(a) 8.36 m inclusive of a 30 mm roof covering where the natural ground level is RL 71.17, being approximately 9.31 m from the southern boundary at a location where the highest part of the building structure (excluding roof covering) is RL 79.50; and

(b) 8.72 m inclusive of a 30 mm roof covering where the natural ground level is RL 70.61, being approximately 3.96 m from the southern boundary at a location where the highest part of the building structure (excluding roof covering) is RL 79.30.

1. By 3 October 2025, the parties must file and serve any further submissions and/or evidence in support of or in opposition to the Applicants' appeals, the subject of these proceedings.
2. Liberty to apply.
3. Costs reserved.

1. On 25 July 2025, the Building Appeals Board (the BAB) determined and answered a preliminary question raised in the proceedings; namely that the natural ground level of the Subject Land, at a point where the RL of the dwelling constructed on the Subject Land is at its highest, had a reduced level (RL) of 71.17, when measured at a distance 9.31 m from the southern boundary of the Subject Land (the Preliminary Question). That determination was made following a hearing conducted over two days; and after the parties had filed written submissions, expert reports and were given the opportunity to call expert evidence and cross examine the expert witnesses of the other parties.
2. The purpose of that determination was to establish a methodology by which the parties could measure the height of the building erected on the Subject Land (the Dwelling), having regard to the definition of height as defined in reg 5 of the Building Regulations 2018 (Vic). In other words, to enable the parties to measure the vertical distance between natural ground level and the top of the roof covering of the Dwelling and thereby determine whether the Dwelling, as constructed, exceeded permissible building height.
3. The difficulty in measuring the vertical distance between natural ground level and the top of the roof covering of the Dwelling was that the topography of the Subject Land had been altered by the development of the Subject Land. Therefore, it was unclear what was the predevelopment natural ground level.
4. Following our determination of the Preliminary Question, further orders were made giving the parties liberty to file any further material by 11 August 2025 in answer to the following question:

What is the height of the building structure erected on the Subject Land (either as-constructed or as-designed), having regard to the natural ground level at the highest part of the building structure being RL 71.17?

1. On 11 August 2025, the Second Interested Party (the MBS) filed a submission, purportedly pursuant to the orders of the BAB dated 25 July 2025 and in answer to the Building Height Question. However, those submissions introduce further evidence and challenge the finding and determination of the BAB that the natural ground level where the Dwelling would be at its highest is RL 71.17. Those submissions stated, in part:
   1. Consistent with the Board's determination, the MBS respectfully submits that the height of the building should not be considered by reference to a single RL of 71.17 alone. Especially, in view of the extent of detail provided on the Reddie survey and other various levels of NGL in proximity of the highest point of the dwelling.
   2. Attached is a survey commissioned by the MBS from a licensed land surveyor which overlays the buildings footprint (with the proposed or as-built conditions) upon the Reddie survey.
   3. From this survey, wall heights and overall building height can be determined in a way that is congruent with the Planning Permit issued.
   4. The MBS invites the Board to consider the MBS' second attachment which provides an estimated RL of 70.32 and to amend its earlier determination to correct the calculation of 71.17 which it has power to do under the "slip rule" (Attachment 2).
   5. It is respectfully submitted that such an amendment of this particular RL will also be consistent with the Board's determination that the NGL as recorded in the Reddie survey, which the Board has ultimately adopted as being correct.
2. As indicated above, the MBS contended that it is open for the BAB to amend its earlier determination and correct the calculation of 71.17.
3. Clause 18, sch 3 to the Building Act 1993 (Vic) (the Building Act) empowers the BAB to correct orders or determinations. That provision states, in part:
   1. Correction of errors

(1) On its own initiative or at the request of a party to a proceeding, the Building Appeals Board or a panel of the Board may make a determination correcting an earlier determination in which there is -

(a) a clerical error or accidental slip or omission; or

(b) an evident miscalculation of figures; or

(c) an evident material mistake in the description of a person, property or thing.

1. The Applicants oppose any correction order being made. They contend that the application made by the MBS purports to challenge the findings and determination of the BAB, which is not permissible under cl 18, sch 3 to the Building Act.
2. In our view, the additional material filed by the MBS is not limited to answering the Building Height Question but also focuses on the same question that was before the BAB and answered in its determination and reasons dated 25 July 2025.
3. We fail to understand why the additional material and the submissions belatedly made were not advanced by the MBS prior to or during the two-day hearing, which focused entirely on that question. Consequently, we find that the BAB is functus officio, insofar as the Preliminary Question is concerned. It has, after hearing considerable evidence and reviewing voluminous material, made a final finding as to what the natural ground level in the area where the RL of the Dwelling is at its highest. It is not open for the MBS or any other party to seek to re-agitate that finding.
4. Further, we do not consider that the material filed or the submissions made fall within cl 18, sch 3 of the Building Act. As observed by the Victorian Civil and Administrative Tribunal in relation to s 119 of the Victorian Civil and Administrative Tribunal Act 1998 (Vic), a provision which substantially mirrors cl 18, sch 3 of the Building Act, that:
   1. ... The slip rule in terms permits to be corrected an error in the judgment or order arising from an accidental slip or omission. An error in a judgment or order which is the product of a deliberate decision is not within the rule. If the judge has made a mistake in his decision, the remedy is appeal; and if no appeal be brought, or if the appeal be dismissed, litigants are bound by the decision, even though wrong.[1]
5. Similarly, in Body Corporate Strata Plan (No. 334479D) v Scolaro's Concrete Constructions Pty Ltd,[2] the Tribunal observed that s 119 could not be used as a backdoor method by which unsuccessful litigants could seek to reargue their case.
6. We adopt the reasoning of the Victorian Civil and Administrative Tribunal in the cases cited above. The avenue for challenging our finding as to the natural ground level is an appeal to the Supreme Court of Victoria.

What is the highest part of the building structure having regard to a RL of 71.17?

1. The matters raised by the MBS in the Further Submissions of the Second Interested Party dated 11 August 2025 highlight some of the difficulties in determining natural ground level for the purpose of assessing building height.
2. Following the hearing on 19 June 2025, we found that the best evidence as to the pre-development topography of the Subject Land was the survey conducted by M.J. Reddie Surveys Pty Ltd dated 22 September 2011 (the Reddie Survey), notwithstanding that that survey was conducted after the original single level dwelling had been constructed on the Subject Land. Therefore, we found it likely that the topography of the Subject Land was altered from its 'pre-development' natural state at some point prior to that survey being conducted.
3. Nevertheless, having regard to the evidence that was before us, we found that the methodology adopted by Mr Leonard was the most appropriate way to determine the natural ground level of the Subject Land in the area where the RL of the Dwelling is at its highest. In that respect, we accepted Mr Leonard's opinion, based on his review of a land survey conducted by Raven Land Surveyors dated 16 November 2024, that the highest RL of the Dwelling is RL 79.5, measured as a ADH (Australian Height Datum).
4. We also accepted Mr Leonard's methodology to determine natural ground level - by taking spot levels from the Reddie Survey on the north and south side boundaries of the Subject Land, being points where it was less likely that the Subject Land had been altered by the construction of the Dwelling or the original dwelling and any associated site works. Mr Leonard then used those metrics to calculate or determine the likely predevelopment natural ground level at a distance of 9.31 m from the southern boundary.
5. However, and in contrast, the MBS belatedly submitted that the height of the Dwelling should not be considered by reference to a single RL of 71.17 alone.
6. In the Further Submissions of the MBS dated 11 August 2025, the MBS submits that an 'estimated' RL of 70.32 should be adopted. However, those submissions do not explain how that 'estimated' RL was arrived at, other than, presumably, relying upon a spot level or levels on the Reddie Survey and at a point thought to be close to what would be the highest RL of the Dwelling. We do not accept that this is an appropriate way to determine the height of the Dwelling, especially where the topography of the Subject Land changes abruptly within a very small area and in all likelihood, because of excavation work carried out when the original single level dwelling was constructed.
7. In our view, taking one or two spot levels to determine the natural ground level in or around the area where the RL of the Dwelling is at its highest could lead to error, especially if the gradient of the land falls away from that point. Importantly, that methodology was not advanced by any party prior to our determination of the Preliminary Question.
8. Indeed, using a single spot level to determine the height of a building structure would be anomalous, especially where the spot level was taken after building works and any associated site works were undertaken and therefore, would not represent the predevelopment natural ground level. That is why we accepted the evidence of Mr Leonard as being the most appropriate way to determine natural ground level. His methodology effectively disregarded changes in topography due to previous disturbance of the ground level when the Subject Land was first developed.
9. In determining natural ground level where the Dwelling has the highest RL, Mr Leonard adopted a methodology that averages the rises and falls in the topography of the Subject Land and assumes a linear gradient falling from the north boundary to the south boundary at a point intersecting at the highest RL of the Dwelling. By applying this method, Mr Leonard was able to determine the natural ground level at a specified point along that line. Obviously, moving along the side boundary (east to west) and from the side boundary (north to south) will change the RL of natural ground level. For example, a measurement taken closer to the front boundary would yield a higher RL of the natural ground level, as the Subject Land slopes away from front to rear. Likewise, a measurement taken closer to the northern boundary would also yield a higher RL of the natural ground level, as the Subject Land falls from north to south. The point where Mr Leonard measured the natural ground level was 9.31 m from the southern boundary along a straight line, drawn perpendicular from one side boundary to the other which intersected with the highest RL of the Dwelling.
10. Apart from the Applicants and the MBS, none of the other parties have filed material which measures the Dwelling height having regard to the definition of height under reg 5 of the Building Regulations 2018 (Vic).
11. The Applicants have relied upon the report prepared by Mr Leonard previously filed in this proceeding. That report states that the top of the Dwelling is RL 79.53.[3] Therefore, the Applicants submitted that the highest part of the Dwelling, adopting a natural ground level of RL 71.17 is 8.33 m, excluding the 30 mm roof covering.
12. According to the Applicants, the roof covering adds 30 mm to the overall height making a total height of 8.36 m.
13. The Applicants' submission assumes that the Dwelling's height is to be measured 9.31 m from the southern boundary, being the point where Mr Leonard opined, and we accepted, that the natural ground level was RL 71.17. We accept that if the Dwelling's height is measured at that point; namely, 9.31 m from the southern boundary, the Dwelling's height is likely to be 8.33 m, excluding the roof covering. However, the question remains whether that is the correct location to measure the Dwelling's height.
14. Mr Leonard calculated that the gradient of the Subject Land falls 2.1 m from north to south over a 20.12 m run. Having regard to the Reddie Survey, the lowest part of the Subject Land, relative to where the RL of the Dwelling is at its highest is at the southernmost part of the Dwelling, following a line north to south as identified by Mr Leonard. Mr Leonard formed the opinion that the natural ground level should be determined at 9.31 m from the southern boundary, consistent with where the RL of the Dwelling is at its highest.
15. However, determining building height is not always determined by reference to where the RL of the building structure is at its highest. For example, a part of a structure which has a lower RL than another part of the same structure might still have a higher height if that lower part of the structure is located on land which falls away. In other words, located on a section of the land which has a lower natural ground level. Therefore, a measurement from that lower natural ground level may yield a higher building height.
16. In this case, it is unclear to us why Mr Leonard determined that natural ground level should be measured 9.31 m from the southern boundary. We presume that this was done because it aligned with the spot level of RL 79.50 marked on the Raven Land Surveys survey dated 16 November 2024, which showed the upper edge of the steel beam at that RL. Although we accepted his evidence that the gradient line from north to south correctly intersected with the highest RL of the Dwelling, that does not necessarily mean that the height of the Dwelling should be measured at 9.31 m off the southern boundary, especially if the land falls away (to the south) from where that spot level was measured.
17. Having regard to the survey conducted by Raven Land Surveyors dated 16 November 2024, the beam height of the Dwelling at the most south-western corner, being the lowest part of the Subject Land where it intersects the upper level of the Dwelling has a RL of 79.30. That location is approximately 3.96 m from the southern boundary. Therefore, we find that the point where building height should be measured is 3.96 m off the southern boundary. If we adopt the same methodology as outlined by Mr Leonard in his report but extrapolating a distance of 3.96 m from the southern boundary, we calculate building height as follows:
    • Gradient = RL 72.3 (North) - RL 70.2 (South) = 2.1 m fall over 20.12 m run (width of Subject Land) = 0.104 m/m.[4]
    • 3.96 m run (distance off southern boundary) over a gradient of 0.104 = 0.41 m.
    • The height of natural ground level at 3.96 m from the southern boundary along the north-westerly end of the Dwelling = RL 70.2 + 0.41m = RL 70.61.
    • Therefore, the building height to the top of the beam at this point = RL 79.3 - RL 70.61 = 8.69 m
    • Assuming 30 mm to the top of the roof covering, the overall height at this point would be 8.69 m + 0.03 m = 8.72 m.
18. Consequently, we find that the Dwelling's maximum height, adopting the definition of height under reg 5 of the Building Regulations 2018 (Vic) is 8.72 m inclusive of a 30 mm roof covering if measured 3.96 m off the southern boundary.

_______________________ ________________________

[1] Stahle v Camberlea Properties Pty Ltd [2000] VCAT 1883.

[2] [2000] VCAT 45.

[3] The measurement of RL 79.53 is taken from a land survey prepared by Raven Land Surveyors dated 16 November 2024 (Report number 9737-04-09-A).

[4] This is the same gradient as measured by Shane Leonard, although for reasons unknown, he has stated this to be 1.04 m/m.