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[2025] ACTSC 558
Supreme Court of the ACT
2025-12-19
Mossop J
Original judgment source is linked above.
Source: the ACT Courts (www.courts.act.gov.au). Converted to plain text by ZoeLaw. Not the official version.
SUPREME COURT OF THE AUSTRALIAN CAPITAL TERRITORY
Case Title: Susa v ACT Planning and Land Authority Citation: [2025] ACTSC 558 Hearing Date: 13 – 15 October 2025 Decision Date: 19 December 2025 Before: Mossop J Decision: (1) The report of Matthew Stevenson dated 22 August 2025 and his oral evidence are admitted into evidence. (2) The time in which the plaintiffs may make an application for review under the Administrative Decisions (Judicial Review) Act 1989 (ACT) in relation to the decision of the Heritage Council constituted by the report or recommendation in its letter dated 24 June 2024 is extended up until 13 November 2024. (3) The decision of the Heritage Council constituted by the report or recommendation in its letter dated 24 June 2024 is set aside. (4) The decision of the ACT Planning and Land Authority made on 26 August 2024 (dated 26 August 2023) in relation to development application 202341493 is set aside. (5) Unless any party seeking an order for costs in its favour files and serves written submissions limited to not more than three pages and any evidence by 16 January 2026, there is no order as to the costs of the proceedings. (6) In the event that any party files and serves written submissions in accordance with order 5, further directions will be made in chambers and, unless the court otherwise orders, the issue of costs will be dealt with on the papers. Catchwords: STATUTES – INTERPRETATION – Planning and development – proposed development of site on heritage register – where Heritage Council advised Planning and Land Authority to approve proposed development despite non-compliance with heritage guidelines – where heritage guidelines picked up from old heritage places register without redrafting to accommodate them in new legislative context – whether advice from Heritage Council under s 60 of the Heritage Act 2004 (ACT) was required to be given in accordance with heritage guidelines due to s 27 of that Act – held that requirement in s 27 qualifies extent to which Heritage Council can give advice based on own opinion STATUTES – INTERPRETATION – Planning and development – whether proposed level in development was a “storey” or a “basement” under Territory Plan 2008 (ACT) – where definition of “basement” refers to “datum ground level” – where “datum ground level” must be determined in a field survey at the time of “Operational Acceptance” for the subdivision, if available – whether expression “Operational Acceptance” can be retrospectively applied – where “Operational Acceptance” is an administrative process of the ACT government and has only existed since 2010 – held that “Operational Acceptance” cannot apply to a subdivision that occurred in 1922 ADMINISTRATIVE LAW – JUDICIAL REVIEW – Error of law – where Heritage Council advice treated mandatory requirement in heritage guidelines as one that was open to be departed from – where Heritage Council did not provide advice about minimising non-compliance – Heritage Council did not give advice in accordance with heritage guidelines – erroneous advice of the Heritage Council meant the Planning and Land Authority failed to consider matters in s 119(2) of the Planning and Development Act 2007 (ACT) – errors of law by Heritage Council and Planning and Land Authority – decisions set aside Legislation Cited: Administrative Decisions (Judicial Review) Act 1989 (ACT), ss 3A(2), 5(1)(f), 5(1)(i), 17 Australian Capital Territory (Planning and Land Management) Act 1988 (Cth) Australian Capital Territory (Self-Government) Act 1988 (Cth) Heritage Act 2004 (ACT), ss 3(a), 3(e), 3A(1)(a)(i), 8, 10(a), 10(e), 18, 20, 25, 26, 26A, 26B, 26C, 26D, 26E, 27, 60, 61, 124, 128, 129, Pt 3, Pt 4, Pt 5, Pt 10, Div 6.2 Land (Planning and Environment) Act 1991 (ACT), ss 8, 54, Pt III, Dictionary Planning Act 2023 (ACT), ss 172, 613 Planning and Development Act 2007 (ACT), ss 54, 119, 120(f), 120(h), 148, 149, 150, Dictionary Planning and Development Regulation 2008 (ACT), s 26(3) Texts Cited: ACT Heritage Council, 20024. Forrest Housing Precinct (Entry to the ACT Heritage Register) Planning and Development (Draft Variation No 352) Consultation Notice 2017 (ACT) Planning and Development (Plan Variation No 300) Notice 2011 (ACT) Planning and Development (Plan Variation No 352) Approval 2018 (ACT) Revised Explanatory Statement, Heritage Bill 2004 (ACT) Territory and Municipal Services, Requirements for Operational Acceptance Submission for Hard Public Infrastructure Works (Issue 2, Revision 3, August 2010) Territory Plan 2008 (ACT) Territory Plan 2023 (ACT) Variation to the Territory Plan No. 56 (27 September 1996) Variation to the Territory Plan No. 173 (4 December 2003) Parties: John Susa (First Plaintiff) Sonia Susa (Second Plaintiff) Australian Capital Territory Planning and Land Authority (First Defendant) ACT Heritage Council (Second Defendant) Derek James Taprell (Third Defendant) Judith Dorothy Clarke (Fourth Defendant) Representation: Counsel P Walker SC with J Bird (Plaintiffs) N Sinnathurai (First Defendant) M Hassall (Second Defendant) Solicitors MV Law (Plaintiffs) ACT Government Solicitor (First and Second Defendants) File Number: SC 373 of 2024 MOSSOP J: Introduction
This is an application for judicial review of two administrative decisions connected with the proposed development of a property on Dominion Circuit in Forrest, ACT (the Site).
It is common ground that the Site is located in a precinct that is subject to heritage protection under the Heritage Act 2004 (ACT). The plaintiffs live next door to the Site and are concerned about the impact on heritage values if the development proceeds.
The owners of the Site wish to undertake a further development of the site. They lodged a development application on 17 March 2023, which was approved on 16 May 2023. The decision to grant that approval was challenged in the Supreme Court and, on 20 December 2023, the decision was quashed and the application remitted to the ACT Planning and Land Authority (ACTPLA) for consideration in accordance with law. On 21 May 2024, the owners of the Site submitted an amended development application. That amended application was referred to the ACT Heritage Council, which provided advice to ACTPLA. ACTPLA then approved the application.
The plaintiffs challenge two decisions made by separate Territory government entities relating to the proposed development on the Site: (a) the decision of the Heritage Council under s 60 of the Heritage Act dated 24 June 2024, which provided advice to ACTPLA (the Heritage Decision); and (b) the decision of ACTPLA under the Planning and Development Act 2007 (ACT) (PD Act) dated 26 August 2023 (but in fact made on 26 August 2024) to approve a proposed development on the Site (the Planning Decision).
The challenge to the Heritage Decision is based upon the proposition that the Heritage Act required advice given by the Heritage Council to ACTPLA in relation to the proposed development to be in accordance with mandatory heritage guidelines, but the advice given was not in accordance with the applicable guidelines.
The challenge to the Planning Decision is based upon the challenge to the Heritage Decision and upon the additional ground that, in accordance with the Single Dwelling Housing Development Code (SDHDC) in the Territory Plan 2008 (ACT), the development could not exceed two storeys, but in fact it comprised three storeys.
The owners of the Site, who lodged the development application, entered a submitting appearance and played no part in the hearing.
It is not in dispute that the plaintiffs, whose property adjoins the Site, are entitled to make the application for relief under the Administrative Decisions (Judicial Review) Act 1989 (ACT) (ADJR Act) or for prerogative relief. Further, there is no issue that the decisions made by the Heritage Council and ACTPLA are both decisions reviewable under the ADJR Act. So far as the Heritage Decision is concerned, there is no issue that the advice given by the Heritage Council to ACTPLA was a “decision” for the purposes of the ADJR Act because it was a “report or recommendation” for the purposes of s 3A(2) of the Act.
The challenge to the Heritage Decision
The legislative framework
References to provisions of the Heritage Act are to those provisions at the time of the Heritage Decision, unless otherwise stated. The objects of the Heritage Act include establishing a system for the recognition, registration and conservation of places that have cultural heritage significance: s 3(a). The objects also include providing a system integrated with land planning and development to consider development applications having regard to the heritage significance of places and heritage guidelines: s 3(e).
A function under the Heritage Act must be exercised in a way that, as far as practicable, achieves the conservation of places with heritage significance: s 3A(1)(a)(i). A “place” is defined in s 8 of the Heritage Act to include a site, precinct or parcel of land.
A place has heritage significance if the place, relevantly, has importance to the course or pattern of the ACT’s cultural history or has importance in exhibiting particular aesthetic characteristics valued by the ACT community or a cultural group in the ACT: ss 10(a) and (e).
The Heritage Council is established by Pt 3 of the Heritage Act. Its functions include identifying, assessing, conserving and promoting places in the ACT with natural and cultural heritage significance: s 18(a). It also has the function of working “within the land planning system to achieve appropriate conservation of … cultural heritage places” (s 18(c)) and any other function given to it under another Territory law (s 18(j)). The examples in s 18 of the Heritage Act make it clear that giving advice to ACTPLA about development applications under the PD Act and its successor, the Planning Act, are functions conferred upon the Council by another Territory law.
The Heritage Register is provided for in Pt 4 of the Heritage Act. The Heritage Register is to include details for each registered place. It must also include each heritage guideline applicable to the place: s 20.
Heritage guidelines are provided for in Pt 5 of the Heritage Act. They are intended to promote the effective conservation of places that have heritage significance: s 25(2)(b)(i). Section 25 provides: Part 5 Heritage guidelines 25 Guidelines about conserving heritage significance (1) The council may make guidelines (heritage guidelines) in relation to the conservation of the following: (a) a place or object registered under division 6.2; (b) an Aboriginal place or Aboriginal object. Examples of matters about which guidelines may be made 1 demolition of registered structures 2 alterations and additions to registered buildings 3 residential heritage precincts 4 rural heritage places 5 new buildings in heritage precincts 6 Aboriginal heritage places and objects 7 working with heritage places 8 developing heritage places 9 when, and when not, to undertake a development affecting the heritage significance of a place Note The power to make a statutory instrument (including guidelines) includes power to amend or repeal the instrument (see Legislation Act, s 46) (2) However, the council may make heritage guidelines only— (a) if the Minister has given the council a direction under section 26C—after the council complies with the Minister’s direction; and (b) if satisfied on reasonable grounds that making the guidelines promotes the effective conservation of— (i) places or objects that have heritage significance; or (ii) Aboriginal places or Aboriginal objects. (3) A guideline is a disallowable instrument. Note A disallowable instrument must be notified, and presented to the Legislative Assembly, under the Legislation Act.
Heritage guideline applicable to the Site
The Site is located in Section 4 of the Division of Forrest. It was first the subject of heritage controls in 1996 when Sections 3, 4 and 8 of the Division of Forrest (together, the Forrest Housing Precinct) were added to the heritage places register in the Territory Plan by Variation to the Territory Plan No. 56 (27 September 1996), pursuant to the provisions of Pt III of the Land (Planning and Environment) Act 1991 (ACT) (Land Act). Amongst the specific requirements for the Forrest Housing Precinct identified in the heritage places register was the following: No dwellings or structures shall be erected between the front boundary and a line drawn along the entrance side of the forward most building and then directly to the closest point on the nearest side boundaries.
Variation to the Territory Plan No. 173 commenced on 4 December 2003. It varied the heritage listing for the Forrest Housing Precinct so as to make clear which requirements were mandatory and which involved the exercise of a discretion. The mandatory or discretionary nature of each of the rules was identified through the use of the words “shall” or “should”, with “shall” indicating a mandatory requirement and “should” indicating a requirement subject to the discretion of ACTPLA. The relevant rule concerning the building line was expressed in mandatory terms requiring that “new dwellings, buildings or structures shall not be permitted closer to a front boundary than the original building line”.
It was this entry in the heritage places register that was in place when the Heritage Act commenced on 9 March 2005. The Heritage Act removed the heritage places register from the Territory Plan but, via transitional provisions, provided that places previously covered by the heritage places register under the Land Act were taken to be registered under the Heritage Act: s 128. It further provided that a requirement under the heritage places register “for the conservation of the heritage significance of a place identified in the register, including any requirement for the conservation of features identified as intrinsic to that heritage significance” was taken to be a heritage guideline under the Heritage Act applying to that place: s 129. It was by this means that the requirements in place at the time when the Heritage Act commenced were given the status of heritage guidelines under the Heritage Act.
Therefore, the heritage guidelines applicable to the Site are those entitled “20024. Forrest Housing Precinct” (Forrest heritage guidelines), being the conservation requirements for the Forrest Housing Precinct taken from the old heritage places register. They are contained in the current Heritage Register. They apply to “Sections 3, 4 and 8 and adjacent road reservations bounded by Melbourne Avenue, National Circuit, Hobart Avenue, Arthur Circle and Empire Circuit” in Forrest.
The Forrest heritage guidelines relevantly describe “The features intrinsic to the heritage significance of the place and requiring conservation” to include “An early C20th ‘Garden City’ planned subdivision” including: … (v) predominantly single storey detached dwellings; … (vii) highly-ordered composition of dwellings, driveways and public space; (viii) dwellings with unifying architectural style, scale and materials; (ix) garages sited towards the rear of the block to deliberately down play the presence of a utilitarian structure in the streetscape and to give emphasis to the garden setting of each dwelling; …
The Heritage Decision
On 31 May 2024, ACTPLA wrote to the Heritage Council to request advice on the amended development application for the Site under s 148(1) of the PD Act.
On 24 June 2024, the advice of the Heritage Council was conveyed to ACTPLA by the Chair of the Council, acting as delegate of the Council. This was what constituted the Heritage Decision. The template on which the advice was provided included, as its first substantive part, a summary of the advice as follows: Pursuant to Sections 148 and 149 of the Planning and Development Act 2007 and Section 60 of the Heritage Act 2004, the ACT Heritage Council advises that: Subject to conditions, the proposed development is unlikely to diminish the heritage significance of the place. Should the ACT planning and land authority decide to approve DA202341493, heritage conditions are identified for inclusion in the Notice of Decision.
The document then recited the background to the request for advice and, under the heading “Advice”, included the following: After review of the application, and as a delegate of the Council, I advise that: • With the exception of the basement ramp, and subject to minor conditions, the proposed development complies with the heritage guidelines for the Precinct and is unlikely to diminish the heritage significance of the place; and • The basement ramp, including part of its concrete sleeper wall, does not comply with the heritage guidelines for the Precinct, as it is sited forward of the original building line. The effect of this non-compliance is minor, and is unlikely to have a significant adverse impact on the heritage significance of the place. As such, design amendments to minimise the heritage effects of the basement ramp are not warranted.
The advice then said that if ACTPLA decided to approve the development application, certain conditions were requested to be included. None of those related to the building line issue. Significantly, the body of the letter concluded: Subject to the above conditions being included in any approval decision, the Council does not object to the approval of DA202341493.
The advice also included, as Attachment A, a table showing the Heritage Council’s assessment of the proposed development against the mandatory and discretionary requirements of the Forrest heritage guidelines. A total of 85 different mandatory or discretionary requirements were identified and addressed. Each of those, except for one, was found to be complied with by the development (either in its proposed form or as a result of the imposition of conditions proposed by the Council) or not applicable to it. The one that was identified as not being complied with was mandatory requirement 2.1b, that “Additions to dwellings or the construction of new dwellings, buildings or structures shall not be permitted closer to a front boundary than the original building line, irrespective of existing encroachments”. The assessment against this requirement described in some detail the determination of the location of the “original building line”. Having identified the position of the original building line, the Council assessed that the proposed development included three components forward of that line: infill works to make good the wall of the existing terrace; the new basement ramp; and part of the ramp’s concrete sleeper wall. So far as the first of these was concerned, the Council considered this work to be a “minor alteration to an existing structure, and not the construction of a new addition or structure” and, impliedly, concluded that it was not contrary to requirement 2.1b. In addition, it explained why this aspect of the works was assessed as “unlikely to diminish the heritage significance of the Precinct”.
The statutory interpretation question
These competing contentions raise a question of statutory interpretation. That exercise must be undertaken having regard to the terms of the Heritage Act interpreted in their total context and having regard to the relevant legislative history of the Heritage Act and the Forrest heritage guidelines.
Under the Land Act, heritage places were protected by their incorporation in the heritage places register, which formed part of the Territory Plan. The Territory Plan was given effect by s 8 of the Land Act which, at the relevant time prior to the commencement of the Heritage Act on 9 March 2005, provided: 8 Effect of plan The Territory, the Executive, a Minister or a Territory authority shall not do any act, or approve the doing of any act, that is inconsistent with the plan.
The “heritage places register” was a defined concept in the Land Act. It was defined as “the register of heritage places incorporated in the plan”: Dictionary to the Land Act. Section 54 of the Land Act defined what the heritage places register was required to contain. Relevantly, s 54 provided: The heritage places register must— … (d) specify requirements for the conservation of the heritage significance of each identified heritage place, including any requirements for the conservation of features identified as intrinsic to that heritage significance; …
As noted above, the requirements in the Forrest heritage guidelines were originally implemented by their inclusion in the Territory Plan through Variation to the Territory Plan No. 56 in 1996. The requirements relating to buildings were specified pursuant to s 54(d) of the Land Act, set out above.
In 2003, Variation to the Territory Plan No. 173 revised the specific requirements in the heritage places register for the Forrest Housing Precinct pursuant to s 54. As pointed out above, the amendments, which included requirement 2.1b in its current form as set out above, introduced a clear and explicit distinction between those specific requirements that were mandatory and those which were subject to an exercise of discretion by ACTPLA.
This was the state of affairs when the Heritage Act came into effect on 9 March 2005. Under the Heritage Act, the relationship between the Heritage Council and ACTPLA was altered. Part 5 of the Heritage Act creates the concept of “heritage guidelines” and Pt 10 set out the relationship between the Heritage Council and ACTPLA in relation to development applications.
Section 25(1)(a) of the Heritage Act provides that the Council may make “guidelines … in relation to the conservation of … a place or object registered under division 6.2”. Division 6.2 provides for the registration of places or objects. The guidelines made under s 25 are referred to as “heritage guidelines”. The examples in s 25(1) indicate that the scope of such heritage guidelines is potentially broad. Section 27 of the Heritage Act is the means by which the heritage guidelines are given effect.
Consideration and decision
The issue in the present case arises because the entry in the heritage places register incorporated in the Territory Plan has been picked up and applied as a heritage guideline without any redrafting to accommodate the change in the legislative context consequent upon the enactment of the Heritage Act. It is that context in which the submissions of the parties raise an apparent competition between the operation of s 27 of the Heritage Act and s 61 of that Act.
Prior to the enactment of the Heritage Act, the heritage places register was given direct effect because the specific requirements for the conservation of places having heritage significance identified under s 54 of the Land Act were incorporated in the Territory Plan, which ACTPLA was obliged to comply with under s 8 of the Land Act. The requirements therefore bound ACTPLA when making a decision upon a development application. Under the Heritage Act, that direct link between the Territory Plan and the decision of ACTPLA was severed. Instead, the decision of ACTPLA was informed by non-binding advice from the Heritage Council. However, the non-binding advice from the Heritage Council itself remained bound by the heritage guidelines via s 27 of the Heritage Act, which required advice to be “in accordance with any applicable heritage guidelines”. While the advice from the Heritage Council was not directly binding upon ACTPLA, if “approval would be inconsistent with any advice” given by the Heritage Council, then there were additional statutory obligations upon ACTPLA under s 119(2) of the PD Act before it could approve a development in the merit track.
The requirement that the advice of the Heritage Council be “in accordance with any applicable heritage guidelines” qualifies the extent to which the advice given by the Council can be based upon its own opinion as to the heritage consequences of a particular development application. It is not open to the Council to provide advice under s 60 which is not “in accordance with any applicable heritage guidelines”, even if the honestly held expert opinion of the Council (or its delegate) is contrary to those guidelines. That gives significance to the formal process for the making of guidelines and the fact that such guidelines are disallowable instruments, capable of being disallowed by the Legislative Assembly: s 25(3) of the Heritage Act. The Legislative Assembly has, by s 129 of the Heritage Act, conferred the same legislative status on conservation requirements in the previously applicable heritage places register under the Land Act. Therefore, those conservation requirements also qualify the scope of advice that the Council may provide.
The Heritage Act was engaged because of the referral of the development application to the Heritage Council pursuant to s 148 of the PD Act on 31 May 2024 and the obligation upon the Council under s 149 to give advice to ACTPLA.
All parties approached the matter on the basis that a referral under s 148 of the PD Act in relation to a development application the subject of the transitional provision in s 613 of the Planning Act was to be treated in the same way as a referral for advice to be given under s 172 of that Act, as referred to in s 61 of the Heritage Act at the time of the referral.
The challenge to the Planning Decision: heritage considerations
As noted above, it was uncontroversial that, notwithstanding its repeal by the Planning Act, the PD Act applied to the development application because the application was lodged and not finally decided prior to the commencement of the Planning Act: see s 613 of the Planning Act. As a result, the relevant version of the Territory Plan was the Territory Plan 2008.
The plaintiffs’ amended originating application asserted that the Planning Decision was an improper exercise of the power given by the PD Act because ACTPLA “failed to give proper, genuine and realistic consideration” to the matters that it was required to consider. The particulars for that ground include that the advice given by the Heritage Council was “flawed” for the reasons given in the challenge to the Heritage Decision.
Under s 119(1) of the PD Act, an application in the merit track could only be approved if it was consistent with the relevant code. Section 119(2) limited the circumstances in which ACTPLA could make a decision which was inconsistent with advice it received from the entities to which it was obliged to refer the application: (2) Also, development approval must not be given for a development proposal in the merit track if approval would be inconsistent with any advice given by an entity to which the application was referred under section 148 (Some development applications to be referred) unless the person deciding the application is satisfied that— (a) the following have been considered: (i) any applicable guidelines; (ii) any realistic alternative to the proposed development, or relevant aspects of it; and (b) the decision is consistent with the objects of the territory plan.
Because of this provision, the content of the advice given by each relevant entity was of significance. If approval of the development application was inconsistent with advice from the Heritage Council, then there would be an additional statutory requirement before the proposal could be approved by ACTPLA.
Separately to s 119, ACTPLA was obliged to consider the advice given by the Heritage Council (s 120(f) of the PD Act) and to consider the probable environmental impacts of a proposed development (s 120(h) of the PD Act), which included the consideration of heritage impacts.
The decision of ACTPLA provided, in relation to the advice from the Heritage Council, as follows (at page 10): ACT HERITAGE COUNCIL – The Council The original DA was referred to the Council who provided advice. The advice and Authority consideration of such advice at that time is noted. The S144A application was referred to the Council who provided advice in summary stating that: Subject to conditions, the proposed development is unlikely to diminish the heritage significance of the place. Should the ACT planning and land authority decide to approve DA202341493, heritage conditions are identified for inclusion in the Notice of Decision. Conditions consistent with the Council’s advice have been imposed in the decision – see Part A above. The Council’s advice was carefully considered noting the representations and in particular Heritage concerns for the proposed development. Noting the detailed Heritage assessment and conditions now imposed in this decision, the Authority is satisfied the development is suitable for (conditional) approval regarding Heritage impacts and issues. A copy of the Heritage advice will be provided on the Authority’s website.
The relevant code
Under s 119(1) of the PD Act, approval could be given to a development application unless the development proposal was consistent with the “relevant code”. “Relevant code” was defined to mean a code that the relevant development table applies to the proposal: Dictionary to the PD Act. A development table, in relation to a proposed development, was defined to mean “the development table in the territory plan that covers the zone in which the development or development proposal is to take place”. The requirements for a development table were described in more detail in s 54 of the PD Act.
The Site is located in the RZ1 Suburban zone. The development table in the Territory Plan for the RZ1 Suburban zone specified that the “relevant code” was the Residential Zones Development Code: Pt 3.1 of the Territory Plan. Rule 1 of the Residential Zones Development Code required single dwelling housing to comply with the SDHDC: Pt 3.2 of the Territory Plan. The Introduction of the SDHDC provided (Pt 3.3 of the Territory Plan): This code has a number of elements. Each element has one or more rules, and each rule has an associated criterion (unless the rule is mandatory). Rules provide quantitative, or definitive, controls. By contrast, criteria are chiefly qualitative in nature. In some instances rules are mandatory. Such rules are accompanied by the words “This is a mandatory requirement. There is no applicable criterion.” Non-compliance with a mandatory rule will result in the refusal of the development application. Conversely, the words “There is no applicable rule” is found where a criterion only is applicable. Development must not exceed two storeys
Rule 2 of the SDHDC required that the number of storeys in the RZ1 Suburban zone not exceed two: Pt 3.3 of the Territory Plan. The rule identified this as being a mandatory requirement by using the words: “This is a mandatory requirement. There is no applicable criterion”. The following relevant definitions were included in the Territory Plan (Pt 13, Pt B): (a) “Storey” was defined to mean “a space within a building that is situated between one floor level and the floor level next above, or if there is no floor level above, the ceiling or roof above but does not include an attic or a basement”. The italicised terms were the subject of separate definitions. (b) “Basement” was defined to mean “a space within a building where the floor level of the space is predominantly below datum ground level and where the finished floor level of the level immediately above the space is less than 1.0 metre above datum ground level”. Once again, the italicised terms were the subject of separate definitions. (c) “Finished floor level” was defined to mean “the level of the upper surface of the relevant floor”.
Datum ground level
As will be apparent from the above, the concept of “datum ground level” is of central importance to the definition of a “basement” and hence of central importance to the application of the two-storey limit.
“Datum ground level”. At the relevant time, it was defined in the Territory Plan as follows (Pt 13, Pt B): Datum ground level means the surface ground level as determined in a field survey authorised by a registered surveyor: a) at the time of Operational Acceptance for subdivision; or b) if a) is not available, provided no new earthworks have occurred; or c) at the date of grant of the lease of the block; whichever is the earliest. Where a), b) or c) is not available, datum ground level is the best estimate of the surface ground level determined in a field survey considering the levels of the immediate surrounding area and authorised by a registered surveyor.
A datum ground level will be expressed as a height in metres above the Australian Height Datum, which is reflective of mean sea level, for example 603.58 m.
The term “Operational Acceptance” used in the definition of “datum ground level” was not defined in the Territory Plan. As discussed in detail below, it is a term that is used to refer to the point at which public works associated with a subdivision are completed and accepted by the relevant approval authorities.
Facts relevant to the datum ground level issue The subdivision, the house and the lease
The Stapleton DGL report
On 21 May 2024, the owners of the Site submitted an amended development application. This was accompanied by a Datum Ground Level Report prepared by a surveyor, Michael Stapleton, dated 22 February 2024 (Stapleton DGL report).
In the Stapleton DGL report, Mr Stapleton: (a) identified the definition of datum ground level in the Territory Plan and recognised that it was necessary for the decision-maker to determine “which aspect of the definition applied” (at [1.1]-[1.2]); (b) “estimated” datum ground level “based on the current ground levels of ground considered undisturbed and the shape of the contours from the Scrivener Contour Survey of 1910” (at [1.5]); (c) assumed that a survey carried out at the time of “Operational Acceptance” would require “an ‘as-built’ survey and not a ‘green Fields’ type survey done before construction” (at [3.8]); (d) reasoned that the “estimation” method contemplated by the definition of datum ground level was a matter for the subjective opinion or discretion of the person making the estimation, and that the datum ground levels should, having regard to the terms of paragraphs a) and b) of the definition, be estimated or ascertained “at the earlier of the time of lease and the time of operational acceptance” (at [3.9]-[3.10]); (e) listed the “contour plans” he “found” for the purposes of preparing his report, which included Charles Scrivener’s 1910 contour map of Canberra, but no further surveys after that time until 1960 (being a date well after the construction of the house on the Site) (at [5.1]); (f) did not describe what actual searches were made for survey plans relevant to the area, even though the report stated that a “thorough investigation was made of sources of levels” and listed the sources found (at [5.1], [6.2]); (g) stated that “[t]he only comprehensive source of levels found prior to 1926 was the 1910 contour map of Canberra prepared under the supervision of Scrivener” and that “[t]hese contours would be indicative of the levels at the time of issue of the lease and commencement of the subdivision in 1926” (at [5.2]); (h) stated that the “1910 survey was done prior to any subdivision works and it is not known what the levels were after clearing and levelling for the purposes of the subdivision” (at [5.5]); (i) concluded that the 1910 survey plan “provides an early indication of the levels of the site” but acknowledged that “the accuracy is questionable” for various reasons (at [5.8]); (j) described that he estimated the datum ground level at or around 1926 based on his own survey and the surveys to which he referred at [5.1] (at [6.18]); (k) made reference to other sources used to inform his estimate, including aerial photography and photographs from the National Archives of Australia (NAA) (at [6.7]-[6.10]); and (l) concluded by deriving the datum ground level at the four corners of the area of the proposed development that would become the basement, the results of which were set out at [7] of his report, ranging from 603.36 in the eastern corner to 604.13 in the western corner.
The Planning Decision
The decision to approve the amended development application was made by Mr Davies as a delegate of ACTPLA on the same day as the referral to the Acting Surveyor-General: 26 August 2024.
The number of storeys in the proposed development was specifically addressed in the Notice of Decision for the Planning Decision under the heading “Part C – Public Notification and Entity Advice” (at page 8): Number of stories – The existing dwelling is 2 stories. The introduction of the basement has been challenged whether it meets the definition of basement which could then be considered a storey (and separate/additional 2-storey new component). The amendment was supported by a detailed datum ground level (DGL) report. A detailed alternative opinion was presented as to DGL and was considered. The age of the original development(s) make establishing the DGL accurately a challenge. This was confirmed by the Office of the Surveyor General within EPSDD. There were a number of photographic elements provided in support and opposed to the DA and DGL findings, many of which were considered inconclusive. Noting the various available and used approaches to apply the ‘best estimate’ approach, the verge (and supporting) data is preferred over construction information to inform the best estimate. Based on available information the Authority is satisfied the DGL information is consistent with the Territory Plan and therefore subsequent development is suitably defined and capable of approval as it meets the relevant Territory Plan requirements. Significantly this suitably defines the key development element as a basement and does not add a storey or cause non-compliance of other parts of the Territory Plan.
Later in the same part of the Notice of Decision, the datum ground level issue was returned to (at page 9): Datum Ground Level (DGL) – As above, the DA was supported with a report consistent with the Territory Plan definition of DGL. The resulting development is considered suitable to be defined as basement.
ACTPLA subsequently provided a Statement of Reasons for the Planning Decision dated 16 October 2024. In that statement, at Annexure B – Further reasons in relation to particular Code requirements, the datum ground level issue was dealt with as follows (at page 20): The amended DA was supported by a detailed DGL report (report of Michael Stapleton, dated 22 February 2024). The finished floor level of the level immediately above the proposed garage space is less than 1.0 metres above the DGL determined by that report.
Annexure C of the Statement of Reasons addressed representations made to ACTPLA in relation to the development application and stated (at page 25): It is noted DGL has been subject of interpretation over recent time ... Ultimately accuracy required to establish absolute compliance or non-compliance is considered unachievable. The passing of time and suitable information is unlikely to establish categorical compliance or not. Therefore based on assumptions and information available, the DA info is preferred as suitable and the best estimate.
Datum ground level calculated using the 1922 survey plan
Evidence was given by Matthew Stevenson, a registered surveyor, based upon this 1922 survey plan. Mr Stevenson had provided the earlier report commenting on the Stapleton DGL report during the development approval process: see [83] above. However, for the purposes of the present proceedings, he was asked to prepare a further report with the benefit of the 1922 survey plan. That report was dated 17 January 2025 (second Stevenson report). This evidence was adduced in order to assist the court to determine whether any error of approach in relation to datum ground level was “material” for administrative law purposes.
The approach taken by Mr Stevenson involved converting the information on the paper-based 1922 survey plan to a modern digital terrain model. This involved converting the measurements on the plan from feet to metres and positioning it over a current digital cadastral database. The contours were then digitised so as to create a digital terrain model. A field survey was then undertaken and a comparison made between locations around the Site and the adjoining block considered likely to be undisturbed since the development of the subdivision and levels determined using the digital terrain model. This showed an average difference of 70 mm. Mr Stevenson concluded from this that the datum ground level determination from the digital terrain model was “reasonable and reliable” (at [4.2.6] of the second Stevenson report).
This contrasted with the approach adopted in the Stapleton DGL report, which involved interpolation from known points likely to be undisturbed along the boundary between the Site and Dominion Circuit and the boundary between two nearby blocks. This involved an interpolation over much greater areas, although it was based upon known recently surveyed points in apparently undisturbed areas.
The difference in the outcomes is illustrated by the different levels estimated for the datum ground level at the four corners of the area that would become the basement. These are summarised in the following table, starting at the northernmost corner and working clockwise:
Stapleton DGL report (at [7]) Second Stevenson report Difference (at Annexure G)
603.38 m 602.818 m 56.2 cm
603.36 m 602.911 m 44.9 cm
604.12 m 603.653 m 46.7 cm
604.13 m 603.554 m 57.6 cm
In each case, Mr Stevenson’s estimate of the datum ground level is substantially lower than that in the Stapleton DGL report. Because the datum ground level is lower, the allowable finished floor level above the proposed basement would need to be correspondingly lower in order to ensure that the basement did not become a storey. Given that the finished floor level above a basement is only permitted to be one metre above datum ground level, that would require it to be no more than one metre above the lowest of the datum ground level reference points in Mr Stevenson’s report, that is, the finished floor level above the basement would need to be no more than 603.818 m. The finished floor level of the level immediately above the basement in the proposed development is 604.35 m, approximately 53 cm higher than permitted for it to meet the definition of a basement.
The levels estimated by Mr Stevenson were also consistent with observations made by a town planner, Pieter van der Walt, in a report dated 22 August 2025. Mr van der Walt reviewed a survey plan prepared by Capital Surveys dated 22 October 2021 that accompanied the development application. He observed spot heights very close to the four corners of the proposed basement of 602.82 m, 602.82 m, 602.99 m and 603 m. In his evidence before the court, he confirmed that these numbers were taken directly from the survey drawing. He also explained that he made an assumption that those numbers showed the datum ground levels because that is commonly the case in surveys submitted with development applications and because the levels were very similar to those in the second Stevenson report, as translated from the 1922 survey plan. From this, Mr van der Walt concluded that the finished floor level immediately above the proposed basement of 604.35 was more than one metre higher than the datum ground level, such that the proposed basement would not meet the definition of a basement.
Plaintiffs’ submissions
Statutory interpretation question
So far as the definition of datum ground level is concerned, the plaintiffs’ argument is based upon an interpretation of the definition which allows the words “Operational Acceptance” to be applied in circumstances prior to the date when that expression was first used. In other words, it allows the expression to be applied to a subdivision which occurred between 1922 and 1927, even though the expression only commenced being used from around 2010. This raises a question of statutory interpretation.
The history of the provisions in the Territory Plan relevant to the determination of datum ground level is as follows. When the Territory Plan commenced in 2008, it included the following definition: Natural ground level means the ground level at the date of grant of the lease of the block.
From 16 December 2011, a definition of datum ground level was inserted by Variation to the Territory Plan No 300 (see Planning and Development (Plan Variation No 300) Notice 2011 (ACT)): Datum ground level means the level of the surface of the ground as defined in a field survey and authorised by a qualified surveyor at the time of operational acceptance for greenfield development or prior to any new earthworks having occurred after that time.
The definition of natural ground level remained unchanged.
The definitions of datum ground level and natural ground level were amended by Variation to the Territory Plan No 352. The Planning and Development (Draft Variation No 352) Consultation Notice 2017 (ACT) provided an explanation for the changes to the definition of datum ground level proposed in that draft variation: cl 2.1.6. B. Datum ground level and Natural ground level The Territory Plan currently uses two different terms to specify ground levels – ‘natural ground level’ and ‘datum ground level’. ‘Natural ground level’ means ‘the ground level at the date of grant of the lease of the block’. In late 2010 a new term for ground level known as ‘datum ground level’ was introduced into the Territory Plan on the advice of the Surveyor-general. This was to bring the terminology in line with standard practice in other jurisdictions and address perceived problems with the use of the term ‘natural ground level’. ‘Datum ground level’ means ‘the level of the surface of the ground as defined in a field survey and authorised by a qualified surveyor at the time of operational acceptance for greenfield development or prior to any new earthworks having occurred after that time’. ‘Datum ground level’ was intended to replace ‘natural ground level’ however, certain Territory Plan codes such as the Residential Boundary Fences General Code, as well as the Planning and Development Regulation 2008 still use the term ‘natural ground level’. Unless all instances of ‘natural ground level’ are identified and amended across all relevant statutory documentation, the definition cannot be removed from the Territory Plan. A solution is to amend the definition of ‘natural ground level’ to state that ‘natural ground level’ means the same thing as ‘datum ground level’. However this raises the issue of the practice in established areas where the ground levels at the date of grant of the lease may be the only ground levels available and/or if ground levels were not recorded as having been established at the time when all civil works were completed (when operational acceptance is granted by the ACT Government entity responsible for city services). The definition of datum ground level aims to establish that the surface ground level at the time of operational acceptance for a new subdivision is the official ground level, whether or not a survey is conducted at that time, but before the commencement of any new earthworks. It is also proposed to amend the definition so that the surface ground level at the date of grant of the lease of the block is acceptable if this occurred before or instead of the above requirement. It is further proposed to include a provision for situations where neither of the above conditions can be met, so that the best estimate of surface ground level as determined by a field survey and authorised by a registered surveyor can be used.
Evidence
At the hearing, there was an objection by ACTPLA to the admissibility of the second Stevenson report and also to the report of Mr van der Walt dated 22 August 2025. The report of Mr van der Walt and his oral evidence were admitted for reasons given at the hearing.
The report of Mr Stevenson of 17 January 2025 and his oral evidence explaining it was admissible notwithstanding that it was not before the decision-maker. It was relevant to the exercise of discretion had the ground of review relating to the datum ground level otherwise been established. It demonstrated that there was a real prospect that, if the decision was set aside, a different estimate of the datum ground level would be made as a result of the use of the 1922 survey plan as part of that estimate process. Should relief be granted?
The conclusions reached above are that: (a) the Heritage Decision provided by the Heritage Council to ACTPLA was not consistent with the Council’s obligation under s 27 of the Heritage Act; (b) when ACTPLA made the Planning Decision, it had regard to the erroneous advice provided by the Heritage Council, with the effect that it did not consider the requirements of s 119(2) of the PD Act; and (c) no error is disclosed in the Planning Decision by reason of the failure to take into account the 1922 survey plan.
The error of law involved in the Heritage Decision meant that ACTPLA approached the decision on the development application on the basis that there was nothing in the Heritage Council’s advice that was inconsistent with approval of the development proposal without any conditions addressing requirement 2.1b of the Forrest heritage guidelines. As a consequence, no consideration was given by ACTPLA to the requirements of s 119(2) of the PD Act. As the terms of that subsection make clear, it would have remained open to ACTPLA to have approved the application if it was satisfied that, relevantly, any applicable guidelines and any realistic alternative to the relevant aspect of the development application had been considered and that the decision was consistent with the objects of the Territory Plan. As there was no evidence led in relation to any realistic alternatives to having the basement ramp and its retaining wall forward of the original building line, it is not possible to reach a conclusion that there is no realistic possibility that compliance with s 119(2) could have made a difference to the outcome of the Planning Decision. In those circumstances, there is no basis upon which to refuse relief.
Under the ADJR Act, the appropriate relief is the setting aside of each decision under s 17(1)(a). In circumstances where that power is available and appropriate to be exercised, it is unnecessary to consider the alternative application for prerogative relief.
Orders
I certify that the preceding one hundred and twenty-six [126] numbered paragraphs are a true copy of the Reasons for Judgment of his Honour Justice Mossop. Associate: Date:
Susa
ACT Planning and Land Authority [2025] ACTSC 558
Finally, there is no issue that the PD Act continued to apply to the Planning Decision notwithstanding that, with effect from 27 November 2023, that Act was replaced by the Planning Act 2023 (ACT). That is because of the transitional provision in s 613 of the Planning Act, which provided that the PD Act applied to a development application that was made under the PD Act and not finally decided before the repeal of that Act. As a result, the relevant Territory Plan, made under the PD Act, is the Territory Plan 2008, not the current Territory Plan 2023 (ACT).
For the reasons that follow: (a) the Heritage Decision involved an error of law because, contrary to s 27 of the Heritage Act, the advice given to ACTPLA was not “in accordance with” an applicable heritage guideline; (b) as a consequence of the error in the Heritage Decision, the Planning Decision involved an error of law; (c) the Planning Decision did not involve an error of law as a result of any error in the approach to the determination of datum ground level and hence the number of storeys in the proposed development; and (d) both the Heritage Decision and the Planning Decision will be set aside under the ADJR Act.
Section 26 provides for public consultation in relation to proposed heritage guidelines. Section 26A defines when, in relation to the consultation period and the registration of a place or object, a heritage guideline may be made. Sections 26B and 26C require a report on public consultation to be given to the Minister and permit the Minister to give certain directions to the Heritage Council. Section 26D provides for revocation of a guideline if the place or object ceases to be registered. Section 26E requires notification of certain persons about a proposed guideline, the making of a guideline or the revocation of a guideline. Section 27 is significant for the present case. It provides: 27 Application of heritage guidelines (1) A function under this Act that relates, directly or indirectly, to the conservation of a place or object must be exercised in accordance with any applicable heritage guidelines. (2) Subsection (1) applies, in particular, to the following functions: (a) the giving of advice to the territory planning authority under section 60 (Advice about effect of development on heritage significance), particularly in relation to ways of avoiding or minimising the effect of a development on the heritage significance of a place or object; (b) the giving of a heritage direction; (c) the giving of a repair damage direction; (d) the making of a heritage order; (e) the making of a heritage agreement.
The making of heritage guidelines, including mandatory provisions, and the significance of heritage guidelines for the advice given to ACTPLA, were specifically recognised in the explanatory material that accompanied the Bill which became the Heritage Act. The Revised Explanatory Statement to the Heritage Bill 2004 (ACT) contained the following: The legislation provides for the development and application of Heritage Guidelines. These are formulated by the Heritage Council and set the policy for how registered places and objects with heritage significance are to be conserved. They may control how development is to take place in an area which is a heritage place or contains a heritage object. They will be performance-based but may include mandatory provisions. … Clause 26 provides for the application of heritage guidelines to functions under the Heritage Act 2004 in relation to heritage places and objects. The application of guidelines is especially relevant in the giving of advice to the ACT Planning and Land Authority about the impact of development applications under section 58, the making of a heritage order, the making of a heritage agreement and the giving of a heritage direction.
The reference to “section 58” in the explanatory statement is to what is now s 60 of the Heritage Act.
Part 10 of the Heritage Act contains provisions that apply to development applications relating to land. Under s 148 of the PD Act — together with s 26(3) of the Planning and Development Regulation 2008 (ACT) and the Territory Plan (specifically, r 44 of the SDHDC and r 61 of the Residential Zones Development Code) — ACTPLA was required to refer the development application to the Heritage Council for advice. Section 149(2) then required the Heritage Council to give its “advice in relation to the development application” within a specified period. If no such advice was given, then it was “taken to have given advice that the entity supports the application”: s 150. ACTPLA was then obliged to consider the advice of the Heritage Council when determining a development application in the merit track: ss 119(2) and 120(f) of the PD Act. It was common ground that the development application for the Site was lodged in the merit track.
Sections 60 and 61 of the Heritage Act provide: 60 Advice about effect of development on heritage significance (1) This section applies if the council is satisfied on reasonable grounds that a development would affect— (a) the heritage significance of a registered place or object; or Note A registered place or object includes a provisionally registered place or object (see s 11). (b) a nominated place or object that, in the opinion of the council, is likely to have heritage significance. (2) The council may give the territory planning authority written advice in accordance with section 61 about its decision. Note 1 If the territory planning authority refers a development application to the council under the Planning Act 2023, s 170 or s 171, the council must, within the number of days prescribed by regulation after the day the authority refers the application, give the authority its advice in relation to the development application (see Planning Act 2023, s 172). Note 2 The council may apply to the ACAT for review of the territory planning authority’s decision to approve a development application if the council— (a) made a representation about the development application under the Planning Act 2023, s 180; and (b) is an eligible entity under that Act, ch 15 (Notification and review of decisions) (see Planning Act 2023, s 504 and s 506 and sch 5, pt 5.2, item 2, item 6 and item 8). 61 Requirements for council’s advice about development (1) This section applies if the council gives advice— (a) under section 60 about the effect of a development on a place or object that has, or is likely to have, heritage significance; or (b) under the Planning Act 2023, section 172 in relation to a development application. (2) The council’s advice must include the following: (a) an outline of the effect of the development on the heritage significance of the place or object; (b) advice about ways of avoiding or minimising the impact of the development on the heritage significance of the place or object. (3) Without limiting subsection (2), the advice may set out proposed conditions on any approval of the development, including conditions requiring compliance with 1 or more of the following: (a) if it is not reasonably practicable for the development to avoid harming the place or object—the reasonable steps that must be taken to minimise the extent of the harm; (b) conservation requirements under applicable heritage guidelines; (c) a conservation management plan approved by the council.
The specific requirements for the conservation of the precinct commence from page 7. Relevant to these proceedings, the following requirement applies: 2.0 CONSERVING LANDSCAPE AND STREETSCAPE VALUES Objective 2.1 - Siting, Setbacks and Garden Settings for all dwellings: To conserve and reinstate the historical arrangement of dwellings across the precinct and the provision of a generous garden setting for each dwelling. Mandatory requirements … 2.1b Additions to dwellings or the construction of new dwellings, buildings or structures shall not be permitted closer to a front boundary than the original building line, irrespective of existing encroachments. … Requirements subject to the discretion of the Authority …
Requirement 2.1b is a mandatory one because, as explained on page 7 of the Forrest heritage guidelines, it uses the word “shall” deliberately. The word “shall” identifies that “the requirement is mandatory and must be complied with in any development or action post-dating gazettal of this Register”.
The assessment concluded that the basement ramp and its concrete sleeper wall did not comply with requirement 2.1b. The assessment then explained why, in the opinion of the Council, these works were “unlikely to diminish the heritage significance of the Precinct”. The assessment was quite detailed. It provided: Basement ramp including concrete sleeper wall The proposed new basement ramp would commence c.21m within the block, from the Melbourne Avenue front boundary, and c.5m forward of the original building line. Excluding the initial transition zone, which has a 1:10 gentle slope, the main descent of the ramp commences c.24m into the block and c.3m forward of the original building line. The concrete sleeper wall also commences at this point, c.3m forward of the original building line. These works therefore do not comply with Mandatory Requirement 2.1b. However, the effect of these works on the heritage significance of the Precinct are assessed to be minor, and these works are unlikely to diminish the heritage significance of the Precinct, as: • Front boundary setback requirements imposed by Mandatory Requirement 3.2a function to conserve key features of the heritage Precinct, which include: “generally uniform front setbacks with occasional variations where one or two houses will have an increased setback to break the unity and create visual interest in the streetscape” (Feature intrinsic (1)(vi)); and “patterns of dwellings in a generous garden setting whereby the gardens enhance the streetscape and form a buffer of landscaped open space between adjacent dwellings” (Feature intrinsic (1)(iv)). • Noting the distance of the ramp from the Melbourne Avenue front boundary, it is unlikely to have significant adverse visual impacts on the heritage streetscape; • Any visual effects of the ramp will be minimised by the tree and shrubs planted along the southern boundary of the existing driveway, including adjacent to the initial descent of the ramp; • Any visual effects of the ramp will be further minimised by the natural grade of the block, which gradually slopes upwards from Melbourne Avenue along the northeast side boundary, will assist in obscuring views to the ramp from the public domain; • The siting of the basement ramp would not diminish the generous front garden setting of the original dwelling, as it occurs wholly within the alignment of the existing driveway; • While the ramp would change the existing side boundary conditions, it does not reduce the setbacks between the two original dwellings within Blocks 3 and 4 Section 4 Forrest; and • The siting [of] the ramp is also not inconsistent with front boundary setbacks in the heritage streetscape, being the southern side of Melbourne Avenue within the registered Precinct boundary, which is characterised by original dwellings with front boundary setbacks of at least 15-20m. In this context, the works are generally consistent with front boundary setbacks in the Melbourne Avenue heritage streetscape, and would not diminish the generous garden setting of the original dwelling, or the existing setbacks between original dwellings within Blocks 3 and 4 Section 4 Forrest. As no significant adverse heritage impacts are likely, design amendments to minimise the heritage effects of the works are not considered warranted. The competing contentions
The plaintiffs contended that the Heritage Decision was beyond power because the Heritage Council was required to apply the Forrest heritage guidelines but did not do so. This was because one of the mandatory requirements in those guidelines was that new structures “shall not be permitted closer to a front boundary than the original building line, irrespective of existing encroachments” and the proposed development would permit new structures in that area. The two structures referred to were a portion of the basement ramp and the concrete sleeper wall.
The Heritage Council took the view that it was open to the Council to advise ACTPLA that, after considering the relevant issues, its view was that the proposed development would not diminish the heritage significance of the Forrest Housing Precinct. The path of reasoning was as follows: (a) Section 61(2) of the Heritage Act required that the advice to ACTPLA “must include” both an outline of the effect of the proposed development on the heritage significance of the place concerned and advice about the ways of avoiding or minimising the development’s impact on the place’s heritage significance. (b) It was therefore not the function of the Council to either support or oppose a particular development application. Rather, its function was to provide advice on the two matters referred to in s 61(2). (c) In providing advice, the Council was required to bring to bear its own views and expertise and give proper, realistic and genuine consideration to the potential heritage impact. (d) The fact that s 27(1) of the Heritage Act imposed an obligation on the Council to discharge its function “in accordance with” applicable heritage guidelines did not permit s 61 to be construed by reference to those guidelines. It did not require the Council to advise ACTPLA that the proposed development would diminish heritage value merely because the Council determined that an individual guideline expressed as a “mandatory requirement” would be breached by the proposed development.
Sections 60 and 61 of the Heritage Act provide the means by which advice from the Heritage Council is fed back into planning decisions.
The Heritage Act included transitional provisions in relation to the transition from the regime which had protection of heritage incorporated within the Territory Plan under the Land Act. Section 129 of the Heritage Act provided: 129 Conservation requirements for places on old heritage places register (1) In this section: conservation requirement means a requirement stated in an old heritage places register for the conservation of the heritage significance of a place identified in the register, including any requirement for the conservation of features identified as intrinsic to that heritage significance. (2) A conservation requirement for a place identified in an old heritage places register is taken to be a heritage guideline applying to the place.
The term “old heritage places register” was defined in s 124 to include “a heritage places register under the Land Act”, which I have referred to simply as the heritage places register.
Immediately prior to the point at which the Heritage Act came into force and the Land Act was consequentially amended, the heritage places register was the register of heritage places incorporated in the Territory Plan.
The Council then gave advice pursuant to s 60 of the Heritage Act. Pursuant to s 61, the Council was required to include in its advice the two matters referred to in s 61(2): (a) an outline of the effect of the development on the heritage significance of the place; and (b) advice about ways of avoiding or minimising the impact of the development on the heritage significance of the place.
Further, s 61(3) gave the Council a discretionary power to set out proposed conditions of any approval, including conditions requiring compliance with, inter alia, “conservation requirements under applicable heritage guidelines”.
The obligation in s 27 then operated when the Council was providing that advice. That is made clear by s 27(2), which makes specific reference to s 27(1) applying to the function under s 60, and hence, necessarily, the requirements for exercising that function in s 61. The requirement in s 27 is that the function of giving advice “must be exercised in accordance with any applicable heritage guidelines”.
So far as the “effect” of the development on the heritage significance of the place is concerned (s 61(2)(a)), the identification of relevant effects will necessarily be based upon the expert opinion of the Council. As pointed out earlier, that expert opinion must be “in accordance with” any applicable heritage guidelines. In the present case, the Forrest heritage guidelines included requirement 2.1b as a “mandatory requirement”. The advice given to ACTPLA identified that the proposal was subject to the Forrest heritage guidelines and that the basement ramp, including its concrete sleeper wall, did not comply with those guidelines. Annexure A to the advice identified that the basement ramp and sleeper wall “do not comply with Mandatory Requirement 2.1b”.
So far as “advice about ways of avoiding or minimising the impact of the development on the heritage significance of the place” is concerned, the advice identified that the effect of non-compliance was “minor” and “unlikely to have a significant adverse impact on the heritage significance of the place”. The Council therefore advised that design amendments were “not warranted”. For that reason, the discretionary power in s 61(3) to set out proposed conditions for any approval “requiring compliance with … conservation requirements under applicable heritage guidelines” was not exercised.
As pointed out earlier, the Forrest heritage guidelines were drafted to be part of the Territory Plan, so that they would bind ACTPLA, which was responsible for making a planning decision in accordance with them. It was in that context that they were stated to be mandatory.
The advice given by the Council was not “in accordance with” the applicable heritage guidelines because: (a) while it did identify that requirement 2.1b in the Forrest heritage guidelines was a mandatory one, that did not give rise to any advice that the mandatory requirement should be satisfied; and (b) it did not provide any advice about avoiding or minimising non-compliance with the guidelines by proposing conditions that would require compliance with the guidelines.
So far as (a) is concerned, the Forrest heritage guidelines draw a clear distinction between those specific requirements which are mandatory and use the term “shall” and those which are discretionary and use the term “should”. The advice did refer in its annexure to requirement 2.1b being a mandatory requirement. However, the mandatory nature of the requirement was not given any effect in the substance of the advice given. Rather than treating the mandatory requirement as something binding upon the Council and governing the terms of the advice that it was required to give, the thrust of the advice given was that non-compliance with the mandatory requirement had negligible heritage significance and was therefore permissible. To adopt this approach was directly contrary to the obligation under s 27. It undermined the formality of the statutory processes put in place for the creation of the heritage guidelines and the statutory provision giving requirements for the conservation of heritage places under the previous legislation the same status as heritage guidelines. By treating a mandatory requirement as if it was open to be departed from, the advice given by the Council treated it as being of the same effect as a discretionary requirement. That failed to reflect the content of the Forrest heritage guidelines and hence was not “in accordance with” them.
So far as (b) is concerned, because the opinion of the Council was that the effect of non-compliance was minor, it provided no advice about “proposed conditions” that would require compliance with conservation requirements under the applicable heritage guidelines. That meant that the advice did not include any articulation of a condition which could be imposed so as to permit the development to proceed in a manner which avoided non-compliance with what was identified by the guidelines as a mandatory requirement. Therefore, the advice did not provide to ACTPLA the tools by which ACTPLA could, if it thought fit, require compliance with the terms of the Forrest heritage guidelines. In circumstances where the advice given under (b) was required to be “in accordance with” the guidelines, the discretion as to whether or not to provide advice about a proposed condition that would address the mandatory requirement miscarried because it was based upon an erroneous approach that the Council’s advice was not required to be in accordance with that requirement.
Although attempting to closely follow the requirements of s 61, the effect of the approach taken by the Council was to prioritise its own opinions as to the heritage significance or otherwise of the departure from the guidelines over its statutory obligation to give advice that was “in accordance with” those guidelines.
One of the grounds of review under the ADJR Act identified in the amended originating application is that the decision “involved errors of law”. That is sufficient to engage the grounds in s 5(1)(f) (that the decision involved an error of law) and s 5(1)(i) (that the decision was otherwise contrary to law) and, in turn, give the court the capacity to grant relief under s 17 of the ADJR Act.
It is notable that there was no reference to the mandatory nature of the requirement in the Forrest heritage guidelines that was infringed by the proposal and no reference, either in the quoted passage or elsewhere, to any consideration of whether or not the conditions in s 119(2) of the PD Act were satisfied.
The decision of ACTPLA was plainly significantly influenced by the fact that there was no advice from the Heritage Council with which approval of the development application would be, relevantly, inconsistent. There were some minor and inconsequential conditions proposed by the Council, not relevant to requirement 2.1b of the Forrest heritage guidelines, which were imposed as conditions of the approval. Had the advice of the Council complied with s 27 of the Heritage Act and been in accordance with mandatory requirement 2.1b, then s 119(2) would have been enlivened, and ACTPLA would have been required to consider the matters set out in that subsection.
While on the basis of the (erroneous) advice given by the Council, ACTPLA complied with its obligations under the PD Act, the decision made by ACTPLA clearly “involved” an error of law in that the erroneous advice of the Council meant that ACTPLA failed to consider the matters in s 119(2) or consider imposing a condition that required compliance with requirement 2.1b so as to avoid any inconsistency with it. That is sufficient to provide a foundation for review of the decision under the ADJR Act. The challenge to the Planning Decision: the datum ground level issue
As part of a representation made in response to the amended development application, the plaintiffs provided ACTPLA with a report prepared by another surveyor, Matthew Stevenson, dated 23 July 2024. That involved a review of the Stapleton DGL report and some testing of its accuracy but relied upon the same underlying sources.
The officer within ACTPLA responsible for dealing with the amended development application was Richard Davies.
On 26 August 2024 at 8:54am, Mr Davies sent an email to the Office of the Surveyor-General. In that email, he asked: “By chance would one of your team have the time to review this DGL report and advise me if the assumptions and methodologies are reasonable”. The reference to the “DGL report” was a reference to the Stapleton DGL report.
The Acting Surveyor-General (Joanne Hawkes) responded to Mr Davies’ email of 26 August 2024 at 3:23pm on the same day. She stated that she “generally agree[d]” with the Stapleton DGL report and provided some brief comments using paragraph numbering that corresponded to the numbering used in the Stapleton DGL report.
There is no evidence that Ms Hawkes inquired as to the searches, if any, that Mr Stapleton conducted when determining whether any survey at the time of “Operational Acceptance” for the subdivision existed. Further, there is no evidence that Ms Hawkes interrogated the records held by her own office when providing her comments about the methodology Mr Stapleton adopted.
“Further reasons” were also given in relation to the datum ground level issue later in Annexure C as follows (at page 27): As above, the DA was supported with a report consistent with the Territory Plan definition of DGL. The resulting development is considered suitable to be defined as basement. The 1922 survey plan
In early November 2024, the first plaintiff obtained from the NAA website a survey plan titled Plan of Levels, Blandfordia Subdivision, Canberra, which was prepared in 1922 (1922 survey plan). This plan was held by the NAA in a record series bearing the reference number A6664, L21. It was prepared under the supervision of Harry Mouat, a licensed surveyor (after whom Mouat Street in Lyneham is named). The first plaintiff also obtained the field book containing the data from which the 1922 survey plan was prepared by conducting a search of a database maintained by the Surveyor-General.
The 1922 survey plan itself showed an area described as “Blandfordia Subdivision” bounded by what is now National Circuit, Melbourne Avenue, Dominion Circuit and Sorell Street. The contour intervals are at one-foot intervals, and the scale is 50 feet to an inch. The plan is based upon what is referred to as the “City Datum”.
The draft variation was approved on 2 February 2018: Planning and Development (Plan Variation No 352) Approval 2018 (ACT). The variation had the effect of substituting the definitions of natural ground level and datum ground level as follows: 27. Natural Ground Level and Datum Ground Level Substitute Natural ground level (NGL) has the same meaning as datum ground level Datum ground level means the surface ground level as determined in a field survey authorised by a registered surveyor: a) at the time of Operational Acceptance for subdivision; or b) if a) is not available, provided no new earthworks have occurred; or c) at the date of grant of the lease of the block; whichever is the earliest. Where a), b) or c) is not available, datum ground level is the best estimate of the surface ground level determined in a field survey considering the levels of the immediate surrounding area and authorised by a registered surveyor.
That is the form in which it existed in the Territory Plan 2008 for as long as that plan remained in effect. The ungrammatical paragraph b) is illustrative of the quality of the drafting of this definition. Paragraph b) must be read as if it provided “if a) is not available, after Operational Acceptance, provided no new earthworks have occurred”.
“Operational Acceptance” is not a concept defined by the Territory Plan. ACTPLA’s submissions explained the concept by reference to a document prepared by the Territory and Municipal Services in August 2010: Requirements for Operational Acceptance Submission for Hard Public Infrastructure Works (Issue 2, Revision 3, August 2010). ACTPLA submitted that the concept should be understood as: a specific reference to the point in time, in the estate development process for a subdivision, at which construction of roads and public works (usually for the whole or most of a subdivision) are complete and are accepted wholesale by Transport Canberra and City Services (TCCS) Directorate as broadly meeting required standards and requirements, such that they are suitable for handover to TCCS for ongoing operation and ownership. (Footnote omitted.)
The submissions of the plaintiffs proceeded on the basis that the concept of “Operational Acceptance” could be applied to the point at which the subdivision which included the Site occurred in 1922. It was on that basis that the plaintiffs contended that the 1922 survey plan could be a field survey of the type referred to in paragraph a) of the definition of datum ground level.
This involved applying the underlying concepts involved with the process which now leads to something called “Operational Acceptance” to what occurred in 1922, when that named concept had not been invented and when (because it predated self-government in 1989) the Territory government did not exist.
In my view, such an interpretation is not an available one. The term “Operational Acceptance” is, as its capitalisation suggests, an identified concept which exists in the administrative arrangements for the subdivision of land by or on behalf of the Territory government. It is an administrative process which, so far as the evidence in this case is concerned, has only existed since about 2010. Necessarily, it is a concept associated with the arrangements made by the government of the Territory established by the Australian Capital Territory (Self-Government) Act 1988 (Cth) and the Australian Capital Territory (Planning and Land Management) Act 1988 (Cth). Had the intention of the drafter been to fix not upon the specific administrative process that existed since 2010 but instead upon the general concept of the point in time at which block layout and subdivision infrastructure was completed, then a form of drafting that did not involve the capitalised concept of “Operational Acceptance” would have been used.
The result of that interpretation is that paragraph a) of the definition of datum ground level can have no application in the circumstances of the present case.
Paragraph b), if given the meaning described at [109] above, does not apply because no “Operational Acceptance” ever occurred.
As pointed out above, the lease in the present case was only granted well after the completion of the subdivision. While the subdivision occurred in 1922, the lease was only granted in 1951. There was no relevant survey as at 1951 that was identified or could be relied upon. The survey most proximate to that date was 1960. As a result, even allowing some modest flexibility in relation to the timing of the survey with respect to the grant of the lease, paragraph c) of the definition of datum ground level is not applicable and hence the datum ground level is required to be determined in accordance with the final portion of the definition.
The Stapleton DGL report provided an estimate of the datum ground level that met the terms of the definition of datum ground level in that it was the “best estimate of the surface ground level determined in a field survey considering the levels of the immediate surrounding area and authorised by a registered surveyor”. There was no challenge to the good faith of the report or the appropriate application of professional skill and judgement in the preparation of the report. The only point made about it was that it had not taken into account the 1922 survey plan, being a field survey that was considered to be relevant and was located in the NAA.
No submission was made that the correct datum ground level was a jurisdictional fact. Therefore, proof in this court that the level determined by Mr Stapleton was not the correct level would not have the effect of invalidating the decision.
The decision-maker considered the report provided by Mr Stapleton. He provided the report to the Acting Surveyor-General, who concluded that its methodology was reasonable. The decision-maker then acted upon that report in order to determine that the area identified as a basement was, in fact, within the definition of a basement and hence that the development would, if approved, result in a building that was two rather than three storeys tall.
The conclusion that “Operational Acceptance” is not a concept that can be retrospectively applied to surveys of subdivisions that were completed before the concept was invented and entered into use in the Territory means that it is not necessary to determine the issue that would otherwise have arisen as to whether or not the 1922 survey plan was one which was “available” at the time that the Planning Decision was made. I would have inclined to the view that a survey plan only available by a search of the NAA and which had not in fact been discovered by a person who was, with the good faith application of professional skill, searching for relevant data, was not “available” in the relevant sense. However, given that I have concluded that “Operational Acceptance” can only apply during the period when that concept was, in terms, used, it is not necessary to form a concluded view.