1. From the written and oral evidence provided at the hearing, and my own observation of the units and trees at the view, I am satisfied of the following facts.
2. The respondents own and occupy a ground floor unit in the complex, unit G03. Unit GO3 has a north facing courtyard which is a unit subsidiary. There is also an east facing courtyard which is a unit subsidiary.
3. The party joined owns and occupies the first floor unit directly above unit G03, unit 103. Unit 103 has a north facing balcony which projects out over part of the northfacing courtyard of unit G03.
4. In 2006 the owners corporation gave the respondents written permission to plant two trees in their courtyard.
5. In fact, three trees were planted and flourished. The three trees are of the variety Albizia julibrissin, commonly called the silk tree. The silk trees are deciduous, and produce a significant amount of foliage during their growing season.
6. In 2010 the silk trees first started to impact on the balcony, and thus the residents, of unit 103. It was suggested that the trees should be pruned to a height below the first floor balcony. While this was initially resisted by the respondents, by 2013 lawyers had become involved, and the trees were pruned later in 2013 as requested.
7. Undaunted, the trees grew back.
8. On 11 March 2015, the owners corporation issued a rules infringement notice to the respondents under section 109 of the UTM Act requiring the silk trees to be pruned to the level of the first floor balcony within 14 days, failing which application would be made to the Tribunal. That notice was not complied with, and so the current proceedings were instituted.
9. The above is the largely uncontentious history of the matter. The parties also asserted a number of more contentious facts. My findings on those contested matters are as follows.
10. I am satisfied that the silk trees grew so successfully that they have at times, despite (or perhaps because of) significant pruning, provided a solid mass of leaves adjacent to, and sometimes encroaching into, the balcony of unit 103. At the height of their seasonal growth, the centre courtyard tree in particular reduces air circulation and light to the north facing balcony and living areas of unit 103. The other trees may also reduce air circulation and light, however they are not situated so proximate to the living area of unit 103.
11. When at a height adjacent to or above the balcony of unit 103, leaves and spent blossoms from any of the silk trees collects on the balcony. The amount accumulating on the balcony depends upon the height and proximity of the tree growth, the time of year, and the prevailing breeze.
12. There was an issue raised as to whether the silk trees impact adversely on the health of the party joined, or her guests or other persons more generally. The party joined gave evidence, and there was also in evidence a medical certificate dated 7 January 2013 to the effect that the trees might be the cause of a skin condition suffered by the party joined. There was also information tendered by the respondents, which did not identify the silk tree as one of the common triggers for asthma or allergy, or as having a high allergenic potential. Information about the kinds of trees located around the units was also submitted, which suggested that there were over 2000 highly allergenic trees growing in close proximity to the units. After having regard to this more objective information I was not satisfied that the silk trees in the unit G03 courtyard posed any particular health risk to the party joined or persons living in close proximity.

1. Section 107 of the UTM Act requires owners and occupiers to comply with Rules of the owners corporation.
2. The Rules of the owners corporation in this matter are the default rules.[1] Two rules were potentially applicable - Rule 5 and Rule 7.
3. Rule 5 provides that in relation to use of the common property:

A unit owner must not use the common property, or permit it to be used, to interfere unreasonably with the use and enjoyment of the common property by an owner, occupier or user of another unit.

(1) A unit owner must not use the unit, or permit it to be used, in a way that causes a nuisance or substantial annoyance to an owner, occupier or user of another unit.

(2) This rule does not apply to a use of a unit if the executive committee has given an owner, occupier or user of the unit written permission for that use.

(3) Permission may be given subject to stated conditions.

(4) Permission may be withdrawn by special resolution of the owners corporation.

1. The term 'unit' in Rule 7 includes unit subsidiaries such as courtyards.[2]
2. Whether Rule 5 or Rule 7 applies in this matter depends upon whether the silk trees are considered to be encroaching into common property when they enter the air space level with or higher than the unit 103 balcony. To put it another way, does the air space above the courtyard of unit GO3 remain the property of unit GO3 as a subsidiary entitlement, or is it common property? The answer to this question depends upon interpretation of the Unit Titles Act 2001 (UT Act) and the registered units plan.
3. Subsection 19(3) of the UT Act provides that the air space above a unit subsidiary which is land must be shown as forming part of that subsidiary, except to the extent of any encroachment:

19 Unit title applications - unit subsidiaries

_(1) A unit title application must show any unit subsidiary as - _

(a) a building, or part of a building, of a kind prescribed by regulation; or

(b) a building, part of a building, or land, that is suitable for a purpose prescribed by regulation.

Note See the Unit Titles Regulation 2001, s 3 for the permissible kinds of unit subsidiaries and purposes.

(2) The application must show any unit subsidiary consisting of a building or part of a building with boundaries defined by reference to the floors, walls and ceilings of the building.

(3) The application must show any unit subsidiary consisting of land as having boundaries unlimited in height except to the extent of any encroachment at, above or below ground level by another part of the parcel.

(4) The application must show unit subsidiaries as annexed to a particular unit, but need not show unit subsidiaries as adjoining the unit.

1. During the view of the complex, it could be seen that the unit 103 balcony projects above part of the unit G03 courtyard.
2. An examination of the registered units plan for Owners Corporation shows a notation on page 11 that the courtyard subsidiaries of the ground floor units are "limited in height from the ground floor level of the courtyard to the projection of the level 1 balcony's soffit." This phrasing is different to that used on pages 31 and 32 of the registered units plan, which simply limit courtyard subsidiaries on level 7 to three metres.
3. The notation on page 11 is ambiguous - it could mean that one draws a horizontal line at the height of the balcony 1 soffit and that is the height limit for the subsidiary; the owners corporation submitted that this would mean that air space above that height limit is common property, although I note that the registered plan does not record it as such.[3]
4. Alternatively, the notation could mean that the height limitation is only for that area of the courtyard that is under the first floor balcony. On the second interpretation, the respondents own all of the air space above the courtyard where it is not encroached upon by the unit 103 balcony, and all of the airspace under the balcony. The unit subsidiary attached to the unit 103 balcony would encompass all the air space in the unit 103 balcony area, and likewise for the next unit above, and so forth.
5. In my view, the second interpretation should be preferred, as it is:
   • (a) consistent with subsection 19(3) of the UT Act, which provides that the height limitation is only 'to the extent of' any encroachment;
   • (b) consistent with the general approach at law that ownership of land includes ownership of the air above it; and
   • (c) avoids an outcome where the registered units plan is non-compliant with subsection 17(3) of the UT Act by failing to specify common property.

Application of Rule 7 - are the trees a nuisance or substantial annoyance?

1. Because the air space where the trees are thriving is taken to be part of the unit subsidiary, and therefore the unit owned by the respondents, Rule 7 becomes relevant. Rule 7 prohibits use of a unit in a way that causes a 'nuisance' or 'substantial annoyance'.
2. Much of the submissions centred on whether the trees create a 'nuisance'. A 'nuisance' at law is a tort. There is a vast body of law about what amounts to a 'nuisance' in the legal sense. However, there is a presumption that words used in a statute are meant to have their ordinary English meaning. It is not clear whether the word 'nuisance' as it appears in default rule 7 is intended to have a technical meaning, and import the legal concept of a 'nuisance', or the ordinary English meaning. In the end it is not necessary to determine that issue because the wording of rule 7 also includes 'substantial annoyance'.
3. Relevantly, the word 'annoyance' means:

noun 1. that which annoys; a nuisance: some visitors are an annoyance.

verb (t) 1. to disturb in a way that is displeasing, troubling, or slightly irritating.

-verb (i) 3. to be disagreeable or troublesome.

1. The word 'substantial' as an adjective has various meanings. In the context in which it appears in rule 7 I consider the second meaning should be adopted:

adjective 1. of a corporeal or material nature; real or actual.

2. of ample or considerable amount, quantity, size, etc.: a substantial sum of money.

3. of solid character or quality; firm, stout, or strong.

4. being such with respect to essentials: two stories in substantial agreement.

5. wealthy or influential: one of the substantial residents of the town.

6. of real worth or value: substantial reasons.

7. relating to the substance, matter, or material of a thing.

8. of or relating to the essence of a thing; essential, material, or important.

9. being a substance; having independent existence.

10. Philosophy relating to or of the nature of substance rather than accidents.

1. The question then is whether the trees amount to a considerable or ample displeasing/troubling/irritating disturbance.
2. I have considered the history of the dealings of the parties, the written and oral evidence provided and viewed the trees (admittedly not in their full splendour due to the time of year). I have seen photographs of the trees at various times and various stages of growth. From this evidence, I am satisfied that the centre tree causes substantial annoyance to the occupants of unit 103 during the months in which it has green leaves. This is because it reduces air circulation and sunlight to the north facing balcony and living area of unit 103, and creates an almost oppressively close wall of foliage. These matters in my view are a displeasing and irritating disturbance to the amenity of occupants of unit 103.
3. This is not to say that every tree planted outside a north-facing balcony is, by virtue of its situation, a substantial annoyance. The peculiarly dense foliage of this tree, at the height of its seasonal growth[4], presents as a green and impenetrable wall at the edge of the balcony, for many months of the year. Situated as it is opposite the living areas of the unit, I am satisfied the central tree is a substantial annoyance.
4. I am not so satisfied in relation to the two other trees, which are located at either end of the courtyard, although they display the same growth habit. This is because those trees are situated more closely to the bedrooms and would not impact so severely on the occupants of unit 103.
5. In relation to the health impacts caused by the trees, I am not satisfied that the trees pose a health impact. The trees are not of a variety which is noted to present a health risk, and many more allergenic trees are located in proximity to the units. It would be an almost impossible evidentiary task to separate any effect on health caused by the silk trees from that caused by other neighbourhood trees, that was not achieved in this matter.
6. Nor am I satisfied that the amount of blossoms or leaves that the trees drop on the unit 103 balcony from time to time is so great or constant as to be a substantial annoyance. While some leaves and blossoms drop, the amount visible in the photographs and on the view were not significant. Even a much higher amount of debris would not, in my view, amount to a substantial annoyance given the short period of time when such a large amount of debris would present itself.

Application of Rule 7 - what about the written permission?

1. Rule 7 does not apply if written permission for the particular use has been provided by the executive committee. Any such written permission can be withdrawn by a special resolution.
2. In this case, permission was given for two trees to be planted. If the middle tree was treated as the third tree, then there would be no permission for it to be planted and as a substantial annoyance it could be the subject of a rules infringement notice.
3. The other two trees, which I consider do not pose a substantial annoyance, could not be the subject of a rules infringement notice.

1. The application before the Tribunal sought enforcement of the rules infringement notice issued 11 March 2015. The application specified that orders were sought to require the owners of unit G03 to undertake on-going maintenance pruning of the trees in the courtyard of Unit G03 to ensure they do not grow higher than the level 1 balcony soffit.
2. There were two problems with the relief sought. First, the orders were directed at all three trees, whereas only the tree which did not have permission to be planted could be the subject of the rules infringement notice, and only the central tree was in my view causing a substantial annoyance.
3. Secondly, the relief sought required action which seemed both practically impossible and, if achieved, more likely to exacerbate than relieve the substantial annoyance. The orders sought required the respondents to prune the trees so that they stayed below the balcony 1 soffit. Given the vigorous growth habit of two to three metres a year exhibited previously, to achieve this outcome the trees would have to be cut back to near ground level every year. Such 'lopping' rather than 'thinning' also seemed to previously have had the effect of creating denser foliage, which led to the impenetrable green wall effect noted above.
4. Thus while it was open to the Tribunal to make the orders sought, at least in relation to the central tree, I formed the view that such orders were likely to be impracticable and ineffective given the evidence and submissions provided at the hearing.
5. When an application such as the present application is filed with the Tribunal, the Tribunal is not limited to making orders enforcing the rules infringement notice as originally issued, nor even to making the specific orders sought by the applicant in the application. The Tribunal is empowered under section 129 of the UTM Act to make any order that it considers reasonably necessary and convenient to resolve the dispute.
6. Accordingly at the resumed hearing I asked the parties whether they would oppose the Tribunal treating the central tree - the one which caused substantial annoyance - as the tree which lacked permission to be planted, and making an order about that tree in order to finalise the matter. The parties were agreeable to that course.
7. Because of the evidence about the previous growth habit of the trees, I was of the view that the only way to resolve the dispute would be to order that the middle tree be removed. I was not satisfied on the evidence that even expert pruning could now salvage the situation being caused by that tree.
8. This was not a conclusion reached lightly. It was clear from the evidence provided by the parties that the presence of the courtyard trees is important in terms of amenity not only for G03 but for other units on that side of the building.
9. Removing the middle tree would impact on the heat level in the courtyard, and consequently in the higher units, particularly in the living areas, in summer. The continued presence of the other two trees may ameliorate that issue to some extent. It may be that when the trees are thinned rather than lopped off horizontally they do not grow quite as densely but are still able to be retained to provide a degree of shade, natural outlook and amenity from which all residents benefit. The point at which the amenity provided by the two approved trees is outbalanced by aspects in which either tree causes an annoyance or nuisance will be a matter which the owners of the ground floor courtyard will have to monitor over time in discussion with their neighbours. It was beyond the scope of these proceedings to control the risk of these or similar issues emerging in the future.
10. Accordingly, I made orders only that the central tree be removed from the courtyard.

[1] The notices issued in this matter referred to previous default rules, which were in the same terms albeit with different numbering.

[2] The definition of 'unit' in the UTM Act refers to section 9 of the Unit Titles Act 2001, which provides that after a units plan is registered, a unit of the units plan includes any unit subsidiary shown on the units plan as annexed to the unit

[3] Section 17(3) of the UT Act requires that a units plan provide that all areas that are not units or subsidiaries are common property.

[4] The density may well have been worsened by regrowth from the earlier lopping to reduce height