Smolak v City of Burnsidenam No ERD-01-1376 [2002] SAERDC 6 (4 January 2002)

Last Updated: 24 June 2002

Court

ENVIRONMENT RESOURCES AND DEVELOPMENT COURT

Judgment of Commissioner Mosel and Commissioner Berriman

Hearing

21/12/2001.

Catchwords and Materials Considered

LOCAL GOVERNMENT --- TOWN PLANNING

Development Application to remove a significant tree (Norfolk Island Pine) - City of Burnside - application refused by the Council - issues limited to the provisions of Principle 141(a)(1)(iv) - Category 4 damage and other cracking and distortions evident in the dwelling in near vicinity of the tree - weight of evidence indicates the tree to be probable cause of cracking to an extent beyond expectations for the dwelling in an area with reactive soils - the terms "substantial damage", "substantial building" and "structure of value" considered - remedial treatment likely to be ineffective and unreasonable in the circumstances - appeal upheld and the decision of Council reversed.

• Development Act 1993 ;
• Environment, Resources and Development Court Act 1993 , referred to.

Representation

Appellant: A J SMOLAK
Counsel: MR M PICKHAVER - Solicitors: CAMATTA LEMPENS

Respondent: CITY OF BURNSIDE
Counsel: MR J HILDITCH - Solicitors: WARD & PARTNERS

ERD-01-1376

Judgment No. [2002] SAERDC 6

4 January 2002

A J SMOLAK

v.

CITY OF BURNSIDE

ERDC No. 1376 of 2001

[2002] SAERDC 6

THE COURT DELIVERED THE FOLLOWING JUDGMENT:

1. Mrs Smolak owns and resides at the dwelling situated at 229 Fullarton Road, Eastwood ("the subject land"). In August 2001, Mrs Smolak applied to the Council of the City of Burnside ("the Council") to remove the large tree situated in her front garden. The application was made pursuant to the Development Act 1993 and was accompanied by a hand written letter and site plan. In her letter Mrs Smolak contends that the position of the tree has caused her house to crack and, as a consequence, problems now occur inside. The Council considered the application and in due course, refused the grant of consent to remove the tree. Its decision and the reasons for so deciding is contained in the decision notification dated 13 November 2001.

2. Mrs Smolak, being aggrieved by this decision, appealed to this Court. There being no settlement reached at the conference held pursuant to the Environment, Resources and Development Court Act 1993, the matter proceeded to hearing. Mr Pickhaver appeared for Mrs Smolak and Mr Hilditch for the Council. During the course of the hearing, the Court viewed the subject land, received exhibits and heard evidence from Mr S Case, a structural engineer, and Mr K Knight, an experienced and qualified arborist and horticulturalist.

3. Mrs Smolak's house is about 100 years old and one of the few original dwellings of the suburb that has been left standing. The original part of the building is constructed of stone with, most probably, a bluestone base. It stands about 4.2 metres from the front boundary (Fullarton Road). It has a solidly constructed verandah across part of its frontage and a driveway along its southern boundary. It is fair to say that the dwelling and its curtilage is not in good condition - a circumstance we suspect has much to do with Mrs Smolak's apparent inability to fully care for an old dwelling on quite a large allotment.

4. The tree concerned is an Araucaria heterophylla (Norfolk Island Pine). It is about 21 metres tall and has a canopy diameter of about 9 metres. Mr Knight estimates its age to be about 60 years although the evidence on this question is equivocal. According to Mr Knight the tree is in average condition, displaying low vigour and symptoms of long term stress. If cared for, the tree can be expected to grow a further 10 metres in height and double the trunk diameter. At present the tree, near its base, is about 1.9 metres in circumference (transcript p.62). The trunk of the tree is situated about 0.5 metres from the Fullarton Road boundary (defined by a fence) and is, at its nearest point, about 1.5 metres from a concrete path adjacent the house and about 2.9 metres from its front wall.

5. It is not disputed that the tree is a "significant tree" within the meaning of that term in Regulation 6A(1)(b) of the Development Regulations 1993. Nor is it in dispute that that which is proposed by Mrs Smolak (tree removal) constitutes "tree damaging activity" and therefore "development" (Section 4 Development Act 1993).

6. The relevant Development Plan is Burnside (City) consolidated 1 February 2001. There are several provisions of the Council's Development Plan which speak about the conservation of significant trees which have important aesthetic and environmental benefits (Council Wide Objective 32 and Principles 139, 140, 141, 142 and 143). However, the parties are on common ground with respect to those provisions most applicable in this matter, that being Principle 141(a)(1)(iv) which is in the following terms:-

"141 Significant trees should be preserved and tree-damaging activity should not be undertaken unless:

(a) in the case of tree removal;

(1) .....

(iv) the tree is shown to be causing or threatening to cause substantial damage to a substantial building or structure of value; and

all other reasonable remedial treatments and measures have been determined to be ineffective."

7. The parties did not call any persons to give evidence in respect of those provisions which speak about the preservation of a significant tree which has attributes conducive to the character and amenity of the local area, the maintenance of habitat or biodiversity or the preservation of a notable visual element. Consistent with the submissions of the parties we have limited our consideration of this matter to those provisions of Principle 141 cited above.

8. Mr Case is a qualified structural engineer. He prepared a statement of evidence for the purposes of this action and also gave oral evidence. In summary, his evidence is as follows:-

•	The house is located in an area of metropolitan Adelaide noted for its highly reactive clay soils.
•	The house is constructed on stone footings and is not designed to accommodate soil movements so characteristic of the soils of the area.
•	His inspection of the property revealed the following:-
Ø	Tilting of the front of the house and, as a consequence, a large crack (Damage Category 4 - AS 2870 - 1996 Residential Slabs and Footings Code) near the front door where two external walls meet.
Ø	Various other cracking of lesser magnitude are evident in other external walls and the distortion of side walls.
Ø	The presence of steel rails and rods to provide structural stability.
Ø	Tilting of the front footpath (nearest the tree) toward the dwelling thereby increasing the possibility of water pooling near the footings.
Ø	Indications of ground settlement around the light pole within the road reserve about 3 metres from the tree.
Ø	The heaving or cracking of the wall defining the front of the verandah.

9. Mr Case concluded that the tree is the most likely cause of the Category 4 crack mentioned previously. He placed a 60%-70% probability on the tree being the cause of the crack. He reached this conclusion having regard to the presence of other cracks of lesser magnitude in walls further away from the tree and by reference to the CSIRO Sheet No.10-91, which information sets out and displays the consequences of subsidence of soils beneath dwellings the cause of which can be directly attributed to large trees near their walls. Mr Case also stated that the most likely cause of the distortion and cracking of the front verandah wall is the presence of roots under it. He reached this conclusion after having acknowledged but dismissing the possibility of the problem being caused by soil swelling from moisture arising from his understanding of cracked water pipes having previously occurred in an unspecified part of the subject land.

10. Mr Case accepted that, given the age and technology of the construction of the house, cracking of walls is inevitable in reactive soils. He stated that the cracking observable in walls further away from the tree are of the type considered to be normal in the circumstances (transcript p.32). He reached this conclusion having regard to the absence of paths around the house, gutter damage and incomplete drains. He is also of the opinion that, in the absence of the tree, the cracking adjacent the front door would not be of a Category 4 magnitude (transcript p.33). He concluded that in the event of several dry years, "additional significant movements of the building can be anticipated" if the tree remained.

11. As to the question of remedial measures after the tree has been removed, Mr Case could provide little assistance to the Court other than to say:-

•	The reversal of the problem is not achievable in the short term because it essentially involves re-moisturisation of the soil.
•	The amount of moisture necessary to have a new equilibrium reached is not easily determined and, if we understand his evidence correctly, it will be a matter of trial and error.

12. We understand Mr Case holds a similar view if the tree was to remain and a re-moisturisation regime was put in place as a remedial treatment envisaged in Principle 141(a)(1)(iv).

13. Mr Knight is an aborist and an expert in his field. He also comes to this Court with experience in the effect and remedies with respect to trees and tree growth in close proximity to buildings. His evidence in relation to the cracking of the house is summarised thus:-

•	The small crack in the footpath is a result of excess water having been applied to pot plants standing against the front wall. Since the path is a "non-engineered" structure with no visible evidence of roots lifting it such a crack can be attributed to the watering or normal seasonal movements.
•	Although his statement of evidence indicates that a root of the tree is the most likely cause of damage to the front wall of the verandah he said in oral evidence that it could have resulted from a burst water pipe - a possibility raised in Mr Case's evidence. In any case Mr Knight, if we understand his evidence correctly, inferred this cracking to be of little consequence and to be expected since he classifies the verandah as a non-engineered structure which "is in all probability not well constructed" (statement p.4).
•	While acknowledging that the tree is a contributing factor to the cracking of the house, Mr Knight said on page 8 of his statement the following:-

"The extent of cracking, the random nature of the damage over the entire building, as well as the long history of crack patching and the presence of long term supportive structures to assist with the wall stability, indicate there have been structural problems in this home for decades.

While the tree will be exacerbating the causative influences of structural instability to a minor extent, it is by no means the major factor. Its removal without attention to the other more important factors previously listed would do little to prevent this situation from deteriorating still further. I base this opinion on the outcomes of many other cases of a similar nature, in which I have been involved.

.....

I also believe the wall movement problems have been made all the worse by the installation of a rigid underpin in circumstances which are on closer inspection, likely to be found unsuitable for their use. The effectiveness of the engineering design and the installation details of this work may also be brought into question upon further examination."

14. On the question of remedial treatment, Mr Knight asserted that a root barrier approach would not be effective. Eventually tree roots will find their way to the environment most conducive to the health of the tree. As a consequence, they will colonise the soil beyond the barrier and again affect soil moisture and consequentially re-establish differential moisture zones and soil reactivity. Mr Knight is firmly of the view that techniques are available to measure, compute and implement re-moisturisation of the soil such that the cracks eventually close. That said, in the circumstances of this action Mr Knight said that a moisture enhancement regime - the result of which could take up to two years to determine - could not be guaranteed to be effective. In that event, Mr Knight said the tree should be removed.

15. The implications to a moisture enhancement regime of the future growth of the tree was put to Mr Knight by the Court after his evidence in respect of its anticipated growth over the next few decades. He said this (transcript p.70):-

"..... the amount of additional moisture that the tree is going to use is not going to be much bigger compared to what the tree is using now. The tree is quite a large tree now. A lot of larger trees don't actually have a particularly great bulk in foliage so as they get to full maturity the amount of foliage they have actually decreases in relation to the woody bulk of the tree. So a fully mature tree doesn't by nature have hundreds of times more than a small tree. It's a matter of the tree having enough foliage to support its requirements."

16. Having considered all that has been put before us and from what we saw on the view, we have reached the following conclusions:-

•

We consider the house and the verandah each to be a "substantial building" or "structure(s) of value" within any reasonable interpretation of those terms of Principle 141(a)(1)(iv). We do not think that the verandah should not be considered a substantial building or a structure of value simply because it may not be an "engineered structure" as put to the Court by Mr Knight.

•

We agree with Mr Case's evidence and that contained in Mr Knight's statement with respect to the cause of the distortion and cracking in the wall of the verandah. The most likely cause is the mechanical action of a large tree root lifting or heaving the soil under the wall. We acknowledge that Mr Knight in his oral evidence raised doubt about this aspect of his written opinion on the basis that the movement could have been caused by soil swelling arising from burst water pipes - a possibility that he became aware of from Mr Case's observations. We do not share that opinion. No evidence, upon which we could rely, supports that conclusion.

•

Principle 141 is not clear about its application to circumstances where a building may have already suffered damage from circumstances other than those arising from a tree. We are of the opinion that it would be wrong to place undue weight on the state of the structure as it stands with respect to this principle. To put it another way, we do not think that a proper application of this principle would discount the effect of subsidence caused by the tree simply because the house is not engineered to withstand soil reactivity or its structural adequacy has already been compromised in one way or another. It seems to us that the principle may be properly applied in circumstances where the damage that has clearly occurred is in excess of that which would arise in the event that the tree were not present.

•

The weight of evidence indicates to us that the most probable cause of the crack near the front door reaching Category 4 damage magnitude is soil subsidence resulting from the depletion of moisture from the soil due to the presence of the tree. We do not accept Mr Knight's evidence on this point. We consider that the tree is a major factor in soil subsidence and cannot be reasonably attributed to seasonal fluctuations in moisture. It is also our opinion that the walls of the building have not been underpinned as suggested by Mr Knight and his assertion that this is a factor is no more than speculation.

•

In the matter before us, we are satisfied for the reasons that follow that the damage caused to both the verandah wall and the wall adjacent the front door is "substantial" within any reasonable interpretation of that term in Principle 141. In the case of the verandah we believe it very likely that a proper repair will involve substantial work or reconstruction albeit with the use of recycled material. In the case of the cracked wall in the house proper we note from Mr Case's evidence that Category 4 damage has the following definition in Appendix C of AS2870-1996 "Residential Slabs and Footings Construction" code. Category 4 damage will involve:-

"..... extensive repair work involving breaking-out and replacing sections of walls, especially over doors and windows. Window and door frames distort. Walls lean or bulge noticeably, some loss of bearing in beams. Service pipes disrupted."

By any measure, a crack in a wall of a dwelling as defined above should be properly regarded as "substantial damage".

We are also of the view that, since the life span of the tree can be anticipated to be at least a further 30 years (Mr Knight's oral evidence - transcript p.69) - a consequence of which is a doubling of the diameter of the trunk - the tree will remain a threat to the structural stability of the house.

•

We are not satisfied with the remedial treatment offered as a solution by Mr Knight. We acknowledge Mr Knight's experience and expertise in this field and respect his determination to preserve trees where possible. However, we do not think that the remedial treatment can be regarded as likely to be effective. At best Mr Knight was not certain on this point. Furthermore, we think that problems that are likely to be encountered in establishing the correct moisture regime - which regime will be conducive to further tree growth (and, consequentially, an ever changing moisture equation) and one in which its effectiveness will not be known for one to two years - could be regarded as "reasonable" as provided for in Principle 141.

17. Mr Hilditch put to us that the "axe should not fall" at this point for two reasons. Firstly, the house is badly damaged perhaps to a point where demolition is indicated. In that case future development would then be designed to accommodate the tree consistent with the many other provisions of the Development Plan that would apply in such circumstances. We do not think that such a course was fully explored by the parties as a serious option. In any event, no evidence as to the future of the ownership or use of the land was put to the Court - they being issues germane to redevelopment decisions.

18. Secondly, Mr Hilditch contends that it would be a premature decision to remove the tree without appropriate opportunity to test the remedies. We acknowledge that Mr Hilditch did not assert that such an approach was implied by Principle 141. That said, the tree is clearly causing the occupant, Mrs Smolak, considerable difficulty and is affecting her lifestyle. We think it unreasonable and unwarranted to take this course given the evidence.

19. We accept Mr Knight's evidence that, even if the tree was removed, the problems with Mrs Smolak's house will not disappear overnight and that particular attention will need to be given to the soil conditions near its footings. Notwithstanding, we are of the view that the tree is the most probable cause of the damage and that its rectification will be unnecessarily impeded and made more complex by the presence of a tree which is clearly inappropriate in the circumstances.

20. The appeal is upheld and the Council's decision is reversed. There will be an order accordingly.