Land and Environment Court New South Wales Medium Neutral Citation: Liu v Ku-ring-gai Council [2021] NSWLEC 1094 Hearing dates: 12 February 2021 Date of orders: 25 February 2021 Decision date: 25 February 2021 Jurisdiction: Class 1 Before: Gray C Decision: The Court orders that: (1) The appeal is upheld. (2) The development control order issued by the respondent on 23 October 2019 is modified in accordance with the terms of the modified development control order in Annexure A. (3) Exhibit 2 is returned. Catchwords: APPEAL – development control order – compliance order – retaining walls and fill on the site – raised levels of rear yard – not authorised by the development consent or construction certificate – no evidence of their design – potential interference with dispersion of water from absorption trench – visual and privacy impacts Legislation Cited: Environmental Planning and Assessment Act 1979 ss 8.18, 9.34 Ku-ring-gai Local Environmental Plan 2015 Land and Environment Court Act 1979 s 39 State Environmental Planning Policy (Exempt and Complying Development Codes) 2008 cl 2.30 Cases Cited: Burwood Council v Ralan Burwood Pty Ltd (No 3) (2014) 206 LGERA 40; [2014] NSWCA 404 Whittaker v Northern Beaches Council [2017] NSWLEC 1379 Texts Cited: Ku-ring-gai Development Control Plan 2012 Category: Principal judgment Parties: Hongbo Liu (Applicant) Ku-ring-gai Council (Respondent) Representation: Counsel: H Liu (self-represented) (Applicant) N Hammond (Respondent) Solicitors: Hones Lawyers (Respondent) File Number(s): 2019/356658 Publication restriction: No Judgment 1. COMMISSIONER: At 1 Sandford Road, Turramurra, there are a number of retaining walls with associated fill that have raised the level of the rear yard up to 2 metres above the natural ground level. Ku-ring-gai Council ("the Council") issued a development control order on 23 October 2019, requiring the removal of the retaining walls and the fill. The applicant, Ms Hongbo Liu, appeals against that order pursuant to s 8.18(1) of the Environmental Planning and Assessment Act 1979 ("EPA Act"). 2. The order was issued on the basis that the construction of the retaining walls and the filling and raising of levels on the site were carried out in contravention of the development consent DA 0604/15 and construction certificate PC16337 for the carrying out of works on the site. 3. The Council maintains that the order should remain in place in circumstances where the works were carried out unlawfully, and cause an unacceptable privacy and visual impact. Further, the Council contends that there is inadequate information to establish that the retaining walls do not interfere with the operation of the site's drainage and stormwater dispersal system, that the imported fill is free from contamination, or that the retaining walls are structurally adequate. The Council's position is that the order should be modified to require that the fill be tested before it is removed from the site, so that the fill can be disposed of appropriately. 4. Ms Liu's position is instead that the retaining walls were constructed as part of the requirements of the stormwater drainage system, and that the retaining walls form part of what has been certified by appropriate professionals. She also contends that the work was carried out in accordance with the design approved in the development consent plans and the construction certificate plans, and that there has been no filling of the site. Further, she contends that the neighbour to the rear has no privacy or visual impact concerns. 5. I have determined that the construction of the retaining walls and the filling of the rear yard required development consent, and the development consent DA 0604/15 and construction certificate PC16337 relied upon by Ms Liu did not incorporate those retaining walls or fill. I have also determined that the retaining walls and the fill are not required for the stormwater drainage system or for the amenity of the rear yard. I also accept that, in the absence of evidence of their design, the retaining walls have the potential to interrupt the subsurface flows from the absorption trench that could lead to the failure of the walls, and that they also have an adverse visual impact. I have therefore determined that the order should be modified to require Ms Liu to restore the rear yard to what was approved by the development consent DA 0604/15. The terms of the order and the power on appeal 1. The order is issued pursuant to s 9.34(1) of the EPA Act, which allows a development control order to be given in accordance with the table to Part 1 of Schedule 5 to the EPA Act. It is issued pursuant to Item 11 of Part 1 of Schedule 5. Item 11 allows a Compliance Order to be issued to the owner of the premises in circumstances where a "planning approval has not been complied with" or a building "has been unlawfully erected and does not comply with relevant development standards". Such an order operates to compel compliance with the planning approval, or require whatever is necessary to be done to bring the building into compliance with the relevant development standards. 2. Consistent with item 11, the order requires: "You are ordered to remove all the retaining walls and fills on the Property that is not permitted under your development consent no DA0604/15 and Construction Certificate no PC 16337." 1. In hearing and disposing of the appeal, the Court has all of the functions of the Council in determining whether the order should be issued (see s 39 of the Land and Environment Court Act 1979 ("the LEC Act")). This includes the power to issue the order pursuant to s 9.34(1) of the EPA Act, which provides as follows: 9.34 Orders that may be given (cf previous s 121B) (1) The development control orders that may be given under this Act are as follows— (a) general orders in accordance with the table to Part 1 of Schedule 5, … 1. In addition, s 8.18(4) of the EPA Act sets out the powers of the Court on an appeal against an order. Those powers are as follows: (4) On hearing an appeal, the Court may: (a) revoke the development control order, or (b) modify the development control order, or (c) substitute for the development control order any other order that the relevant enforcement authority who gave the order could have given, or (d) find that the development control order is sufficiently complied with, or (e) make such order with respect to compliance with the development control order as the Court thinks fit, or (f) make such other order with respect to the development control order as the Court thinks fit. 1. Even if the statutory requirements for the issue of an order in Items 3 and 11 of Part 1 of Schedule 5 are met, the use of the word "may" in both s 9.34(1) and s 8.18(4) imparts on the Court a discretion as to whether to issue an order (s 9.34(1)) and to consider the appropriate orders on the hearing of an appeal (s 8.18(4)). The site and the unauthorised retaining walls and fill 1. The hearing commenced with a site inspection. The subject property is described as Lot 44 DP 11414 and is known as 1 Sandford Road, Turramurra. It is located at the end of the Sandford Road cul-de-sac, and the driveway entrance is on the northern side of the bulb of the cul-de-sac. Travis Park adjoins the site on its eastern boundary. 2. The site is zoned R2 Low Density Residential under the Ku-ring-gai Local Environmental Plan 2015 ("KLEP 2015"). It has a total site area of 1284m2 and a frontage of 21.335m to Sandford Road. The site has a fall from west to east by around 1.8m, and from south to north by around 0.6m. 3. The rear boundary of the site is contiguous with the rear boundary of 76 Murdoch Street, Turramurra. 4. A 2-storey dwelling and swimming pool are situated on the site, and were constructed as a result of development consent DA 0604/15 and construction certificate PC16337. 5. The retaining walls are constructed of cement block, along the eastern property boundary, 5m from and parallel to the rear boundary, along the rear boundary, and between the retaining wall 5m from the boundary and the rear boundary retaining wall. Their locations are depicted in Figure 1, and a photograph of four of the walls, taken from the west in the rear yard at 76 Murdoch Street and looking to the east toward the public reserve, is shown at Figure 2. 1. The retaining walls and the associated fill are described in the order in the following way: "a) A cement block retaining wall has been erected along the rear eastern property boundary to a height of up to 2.0 metres; b) Another cement block retaining wall approximately 12.0 metres in length has been erected 5.0 metres from and running parallel to the rear property boundary. This wall also stands at a height of up to 2.0 metres; c) The area bordering the above retaining walls and the rear of the new dwelling have been filled and the level of the land raised; d) Another cement block retaining wall has been erected along the rear property boundary up to a height of 1.60 metres; e) Another cement block retaining wall 0.90 metres in height is erected between the retaining wall at item b) and the wall at the rear boundary at item d) above. 1. It was clearly evident from the site inspection that the retaining walls, together with the fill, have the effect of raising the finished level of the rear garden to around 140 AHD from its natural level of around 138 AHD. The result is that most of the rear yard is level with the finished floor level of the dwelling house. Given the large natural fall within the rear yard (from 140.20 AHD on the stone tile decking adjacent to the rear yard, to 137.37 AHD at the north eastern corner of the site), the retaining walls are required to be of the height constructed to retain this fill. The development consent 1. Development consent (DA0604/15) was granted on 3 May 2016 for the demolition of an existing dwelling and the construction of a new dwelling, double garage and pool. The approved dwelling has a finished floor level at ground level which is at or near grade to the western rear portion of the site, where the site is at its highest. 2. A construction certificate was issued on 28 November 2016, and was accompanied by a number of plans. In accordance with s 4.16(12) of the EPA Act, the construction certificate is taken to "form part of the relevant development consent". Further, the construction certificate prevails over the development consent plans to the extent of any inconsistency: see Burwood Council v Ralan Burwood Pty Ltd (No 3) (2014) 206 LGERA 40; [2014] NSWCA 404 at [202]. 3. Both the development consent plans and the construction certificate plans show the rear yard having a natural fall away from the location of the pool and the finished floor of the decking area around the dwelling. This is clearly shown in the landscape plan (Ex 3) to be an area turfed with buffalo grass that maintains the natural fall of the land. That natural fall is from around 140 AHD at the pool surrounds and decking, to 138 AHD at the north-eastern turfed area of the rear yard, a fall of around 2m, with a further fall of around 0.75m to the boundary. 4. The development consent, and the construction certificate, both approve the construction of stormwater management system that relies on a sub-surface absorption trench within the rear yard. The size of the absorption trench, as approved in the construction certificate, is 10 x 5m. The pit surface level of the absorption trench, shown in the cross-section, is 138.20, which is consistent with the natural ground level of the rear yard prior to the carrying out of the development. The Council's position on the appeal 1. The Council submits that the retaining walls and the fill were not authorised by the consent and did not fall within the category of exempt development under the State Environmental Planning Policy (Exempt and Complying Development Codes) 2008 ("SEPP ECDC"). The Council relies on the expert opinion evidence, outlined in detail below, that the retaining walls and the fill cause an unacceptable privacy and visual impact, which is inconsistent with what the Council typically considers acceptable in the residential zone. The Council submits that the changed relationships between the rear yards of 76 Murdoch Street and 1 Sandford Road is clear from the site surveys, and is the direct result of the retaining walls and the fill, which causes the privacy and visual impact. 2. Further, the Council contends that there is inadequate information to establish that the retaining walls do not interfere with the operation of the site's drainage and stormwater dispersal system, or that the retaining walls are structurally adequate. It relies on the expert opinion evidence that the stormwater system should not have been certified given that the absorption trench was installed at a level higher than that approved, and that the retaining wall will potentially undermine the operation of the absorption trench system. This evidence is outlined below. 3. The Council also contends that there is no evidence that the imported fill is free from contamination, and comprises virgin excavated natural material ("VENM"). Accordingly, the Council seeks a modification to the order that requires testing of the soil to ascertain whether the fill is VENM, a remedial action plan if it is not VENM, and a construction management plan demonstrating how the fill material is to be removed and the retaining walls demolished 4. The Council therefore seeks that the order remain and be modified by the Court, as follows: "TERMS OF THE ORDER: 1. You are ordered to remove all the retaining walls and fills on the Property that is not permitted under your development consent no. DA0604/15 and Construction Certificate no. PC16337. 2. Prior to the commencement of any work in relation to (1) above, an appropriately qualified land contamination expert is to undertake soil sampling of the fill material at the rear of the Property, for the purposes of determining if the fill material is contaminated or not. Soil sampling of the fill material is to consist of a minimum of 3 boreholes that extend to a distance of 200mm below the bottom of the eastern and northern retaining walls. Testing is to confirm that the fill material is free from contamination and constitutes Virgin Excavated Natural Material (VENM). The land contamination expert who undertakes the soil sampling is to provide to a written report to Ku-ring-gai Council's Coordinator Compliance Services on the findings of the soil sampling of the fill material within 7 days of the testing being completed. 3. If the soil sampling of the fill material required by (2) above identifies that the fill material is contaminated or not of a type that is classified as VENM, the land contamination expert is to prepare a remediation action plan (RAP). A RAP and site audit statement (SAS) are to be prepared by an appropriately qualified expert, and must address all site contamination and remediation issues identified as part of the soil sampling. The RAP is to provide a methodology for the safe removal and disposal of the contaminated fill material as well as ensuring that the rear of the site is to be remediated to the standard for a low density residential property that is free from restriction. A copy of the RAP shall be submitted to Ku-ring-gai Council's Coordinator Compliance Services within 7 days of it being completed. The site audit statement is to be submitted to Council within 14 days of all remediation works being completed. An accredited site auditor is to be appointed to manage all recommended site contamination and remediation measures. 4. Prior to the commencement of any demolition or fill removal works, a Construction Management Plan (CMP) prepared by a suitably qualified engineer is to be submitted to Ku-ring-gai Council's Coordinator Compliance Services demonstrating how the fill material is to be removed and the retaining walls demolished. This plan is to detail how the works are to occur within the boundaries of the site. No access or the undertaking of any work is to occur from the adjoining Council reserve to the east. To ensure this, the CMP is to show construction fencing along the length of the eastern boundary and be installed prior to any works commencing." 1. The Council proposes a period of 90 days for all of the above to be undertaken. The applicant's case on appeal 1. Ms Liu submits that all the works have been done in accordance with the Building Code of Australia and design documents. She says that throughout construction, the structural engineer, stormwater engineer and the principal certifying authority all carried out site inspections at different stages, and issued the compliance certificates following the final inspections. She therefore submits that the retaining walls were constructed pursuant to development consent no. DA0604/15 and Construction Certificate PC16337. 2. Ms Liu submits that the retaining walls were constructed as part of the requirements of the stormwater drainage system, and that the retaining walls form part of what has been certified by appropriate professionals. In support of this submission, she relies on the certifications attached to her Statement of Facts and Contentions, which can be described as follows: * The certification of the stormwater system by Allied Consultants dated 8 February 2019, which certifies that "the stormwater system including rainwater tank and absorption trenches were generally installed in accordance with design documents". * The installation certificate by Well Design Construction dated 16 February 2019, which certifies that "the stormwater has been installed… in accordance with approved plans and connected to the kerb". * The certification of the building structural works by Allied Consultants dated 8 March 2018, which certifies the reinforcement of strip footings, ground floor slab, raft slab, first floor suspended slab and swimming pool. 1. Additionally, following the evidence and closing submissions at the hearing on 12 February 2021, I made a direction for the Council to file and serve its proposed modified development control order, and gave an opportunity to Ms Liu to provide written closing submissions in reply. Despite making it clear to Ms Liu that she was not permitted to introduce further evidence in her reply submissions, Ms Liu attached an email to the reply submissions which contained a certification by Aiping Wen from Allied Consultants dated 18 February 2021 as follows: "We missed including the retaining wall in our issued structural compliance certificate. I confirm that I have inspected the reinforcement of the retaining wall and retaining wall footings, we considered the reinforcement was installed in accordance with design documents, the constructed retaining walls should function as per design intent. This statement shall not be constructed as relieving any other party of their responsibility, liabilities or contractual obligations." 1. Ms Liu submits that these certifications are by professionals and are sufficient to verify that the absorption trench system and the retaining walls were installed in accordance with the design documents. Further, she submits that the Occupation Certificate dated 21 April 2020, and the endorsement of the positive covenant by the Council that is now registered on title, would not have been issued if the works were illegal. She submits that each of the certifications were issued following an inspection, and therefore can be relied upon. 2. She also submits that the site has not been filled, and relies on the Survey Report by BPS Surveyors dated 3 July 2018. 3. Ms Liu also submits that the expert reports and the expert evidence given in Court cannot be relied upon in circumstances where they rely on the wrong drawings. She says that the plans relied upon were Revision B, whereas they should have been Revision C. She submits that the retaining walls were based on the plans given to the builder and the professional engineers, and comply with the typical detail for retaining walls which can be found on the construction certificate plans. She submits that the retaining walls were a structural requirement from the private certifier. Ms Liu considers that the correct plans for the development consent are attached to the Statement of Facts and Contentions, and the correct plans for the Construction Certificate are A101, A122 and Structural Plan 01SAND-ST3 Revision D submitted on 12 February 2021. 4. Ms Liu submits that she complied with all the rules and regulations, and provided the requisite information to support the retaining walls to a council officer. With respect to the retaining wall that is around 5m from the rear boundary, Ms Liu contends that it should be considered exempt, given its distance from the boundary is greater than 2m. She also contends that the retaining wall along the rear boundary is less than 600mm. 5. Further, she contends that the neighbour to the rear has no privacy or visual impact concerns. 6. Finally, with respect to the Council's proposed modified order, Ms Liu submits that there is no evidence that the soil may be contaminated as it is all sourced from her own property, and that the removal of the fill will remove the soil from around the absorption trenches which will cause them to fail. The evidence before the Court 1. In order to assist the Court on the issues before the Court on the appeal, expert opinion evidence was given by Mr Adam Richardson, a qualified town planner employed by the Council, and Mr Brian O'Connell, a qualified engineer employed by the Council. Ms Liu questioned the experts in cross-examination. These questions did not lead them to change or modify their expert testimony. 2. Although Ms Liu submits that the retaining walls and associated fill were constructed as part of the requirements of the stormwater drainage system, and that there are no privacy or visual impacts associated with their construction, she does not adduce any expert evidence in support of that position. Whilst it is open to her to take such an approach, the result is that there is no expert evidence to support her case and no evidence given to contradict the expert opinion evidence adduced in the Council's case. I described the purpose of expert opinion evidence in Whittaker v Northern Beaches Council [2017] NSWLEC 1379 at [19]: "19 Even though the rules of evidence do not apply in development appeals (s38 of the Court Act), expert evidence is given when a party wants to adduce evidence of an opinion regarding an issue raised in the proceedings that falls within the expertise of that expert. Ordinarily, the opinions of witnesses are not considered in evidence. In that respect, there is a distinction between evidence of facts and evidence of opinion. Usually witnesses give evidence of facts, that is, things that have been seen or heard. It is then the role of the Court to make an inference or draw a conclusion based on the evidence of the facts. However, an exception to this is when a witness has specialised knowledge. Where an issue arises that concerns a specialised area, the Court may not have that specialised knowledge and is therefore assisted in drawing the inferences or conclusions by the opinion of an expert with specialised knowledge. If a party seeks to adduce the opinion of such an expert, the evidence must be given in accordance with Part 31 Division 2 of the Uniform Civil Procedure Rules 2005 ("UCPR")." 1. The content of the Statement of Facts and Contentions filed by Ms Liu, does not amount to evidence of expert opinion. The author, Ms Liu, is not relying on having specialised knowledge in the area of engineering or town planning, and the document was not prepared in accordance with Part 31 Division 2 of the Uniform Civil Procedure Rules 2005 ("UCPR"). As such, the Statement of Facts and Contentions can only be taken into account as the contentions (or arguments) that she puts before the Court, and insofar as it records facts. 2. Similarly, the certifications attached to the Statement of Facts and Contentions, which are relied upon by Ms Liu, do not constitute expert opinion evidence. Even though the qualifications of the authors are referenced, the documents were not prepared or filed in accordance with Part 31 Division 2 of the UCPR, the experience of the authors are not known, they did not participate in a joint conference with the other experts in accordance with the Court's policies, and were not available for cross-examination. As such, I cannot take into account the certifications as expert opinion evidence. Evidence concerning the retaining walls and the operation of the stormwater system 1. Mr O'Connell's evidence is that there is no engineering requirement to provide fill and retaining walls for the successful operation of the stormwater drainage system, which includes the operation of the absorption trench dispersal system. His evidence is also that the retaining walls will potentially undermine the proper functioning of the stormwater system. The evidence contained in his expert report concerning this issue is as follows (Ex 4 p 5): "6) There is no engineering requirement to provide fill and retaining walls for the successful operation of the stormwater drainage system. The stormwater system as proposed on the DA and CC plans, which proposed excavation of the existing ground levels for installation of the trenches, and reinstatement of these existing ground levels over the trenches, was satisfactory. This arrangement was considered satisfactory by 2 separate consultant engineers, and assessed and approved by Councils engineer. 7) There was no requirement to construct the retaining walls to hold and prevent soil from sliding over to the other side. 8) The provision of the retaining walls may actually undermine the proper functioning of the stormwater system. An absorption system works on the basis of stormwater being absorbed from the absorption trench into the surrounding soil. This water is then dissipated into the surrounding areas by subsurface flows. The pre-development subsurface flows would have followed the contours of the land to travel in a northeastern direction towards the reserve. The retaining walls along the north and eastern boundaries have interrupted these subsurface flows." 1. There is no expert opinion evidence relied upon by Ms Liu that contradicts this evidence. Evidence concerning the structural stability of the retaining walls 1. Mr O'Connell opines that the interruption of subsurface flows by the retaining walls can lead to an accumulation of water at the back of the retaining walls, which can create hydrostatic pressure and lead to the failure of the walls. His evidence is that the hydrostatic pressure may not develop "if the retaining walls were designed by a suitably qualified and experienced engineer. Methods for relieving hydrostatic pressure include; careful construction with engineers supervision, weep holes, drainage pipe behind the wall." 2. His evidence is that whilst weep holes have been observed at the bottom of the walls, there is no evidence of an engineer's design for the wall, or evidence that there is a drainage pipe behind the wall. His evidence, based on a visual inspection of the wall on the eastern boundary, is that there is a poor standard of workmanship. 3. There was no expert opinion evidence relied upon by Ms Liu that contradicts this evidence. She relies on the certification of the stormwater system by Allied Consultants dated 8 February 2019. However, this certification makes no comment in relation to the retaining walls and the fill, and only certifies that "the stormwater system including rainwater tank and absorption trenches were generally installed in accordance with design documents". Ms Liu also relies on the installation certificate by Well Design Construction dated 16 February 2019, which certifies that "the stormwater has been installed… in accordance with approved plans and connected to the kerb". She also relies on the certification of the building structural works by Allied Consultants dated 8 March 2018, which certifies the reinforcement of strip footings, ground floor slab, raft slab, first floor suspended slab and swimming pool. 4. None of these certifications relied upon by Ms Liu provide any certification with respect to the design and structural stability of the retaining walls. 5. The additional certification relied on Ms Liu, attached to her submissions in reply and in the form of an email that was not tendered in evidence in the course of the hearing, is not sufficiently detailed to contradict the evidence of Mr O'Connell. Evidence concerning the privacy impact of the walls and the fill 1. Mr Richardson's evidence is that, as a result of the earthworks and retaining walls, there is an approximate difference in ground levels of up to 2m between the two properties. His evidence is that this significant difference in ground levels allows "a person at the subject site to look directly into and over the rear private open space of 76 Murdoch Street as well as into the rear habitable rooms of the dwelling." He opines that this is an unacceptable impact on the privacy of occupants of 76 Murdoch Street. 2. Mr Richardson points out that the result of filling of the land is that there is a changed relationship between the rear yards of 76 Murdoch Street and 1 Sandford Road, which causes this privacy impact. Whereas, prior to the development being carried out at 1 Sandford Road, the levels of each of the rear yards was such that the rear yard of 1 Sandford Road is lower than the rear yard of 76 Murdoch Street, this relationship has changed such that the rear yard of 1 Sandford Road is higher than that of 76 Murdoch Street. In support of this opinion, Mr Richardson relies on the survey of 1 Sandford Road that was provided in support of the development application for the construction of the dwelling (dated 4 August 2015), as well as the survey of 76 Murdoch Street that was provided to the Council in support of a development application for alterations and additions to the dwelling on that property (dated 3 November 2016). The survey levels shown thereon clearly establish that the lowest point of the rear yard of 1 Sandford Road, prior to the carrying out of works, is 137.5 AHD, which is lower than the height of the pool coping and surrounds of 76 Murdoch Street, which is 138.13 AHD. From the site inspection it is evident that the height of the rear yard, in the area filled, is substantially higher than the pool surrounds of the rear yard of 76 Murdoch Street. 3. Whilst Mr Richardson agrees that the privacy impacts on 76 Murdoch Street are partially mitigated through the boundary fencing between the two properties, an uninterrupted view from the subject site into 76 Murdoch Street is nonetheless still available from the lawn area of the subject site above the fill, "as this area is higher than the new boundary fence." Whilst he considers that this could be resolved by "a further fence on top of the retaining wall to the lawn area, along with, screen planting and landscaping or a combination of these" (Ex 3 p 8), this would exacerbate the visual impact of the retaining walls, which he also considers to be unacceptable (see below). 4. Mr Richardson opines that these privacy impacts result in development that is contrary to the objectives in Part 23.9 of the Ku-ring-gai Development Control Plan 2012 ("KDCP 2012") concerning privacy. Three of these objectives are as follows: "1 To ensure the impact of development on the visual privacy of neighbouring occupants is minimised. 2 To ensure that the level of visual privacy to principal living areas and private open spaces is appropriate to the development type. 3 To ensure high standards of visual privacy for all occupants within low density residential development." 1. He opines that the loss of privacy suffered by the occupants of 76 Murdoch Street means that these objectives are not met, and that, therefore, this loss of privacy is unacceptable and would not have been permitted, if approval had been sought prior to the construction of the retaining walls and the filling of the land. 2. There is no evidence relied upon by Ms Liu that contradicts this evidence concerning the privacy impacts. She asserts that the neighbour is not concerned about the privacy impacts, but has not furnished any evidence in support of this proposition. The text message relied upon by her does not constitute such evidence, as it relates only to the timing for the construction of the retaining wall and border fence. Evidence concerning the visual impact of the walls and the fill 1. Mr Richardson's evidence is that the extent of the retaining walls (up to 12m long), their height of up to 2m, and their location parallel with the side and rear boundaries, means that they are visually dominating when viewed from the public domain to the east. The eastern wall, he opines, has a dominant effect that far exceeds the effect of a typical lightweight boundary fence. He considers that this visual impact could not be mitigated by landscaping, and is unacceptable in its context. 2. Similarly, with the rear boundary, Mr Richardson's evidence is that whilst their visual impact is obscured by a boundary fence, to screen the walls the boundary fence is in excess of 1.8m in height and is visually dominant, which is of greater height and visual impact than what is acceptable in a domestic context. 3. Mr Richardson points out that where retaining walls are proposed in a development application, the KDCP 2012 requires that they be setback 2m from the boundaries to facilitate and provide sufficient area for landscaping to screen the visual impact of the retaining walls. He relies on control 12 of Part 4A.2 of the KDCP 2012, which requires that side setbacks "are to accommodate shrubs to a height of 3-4m for two storey houses, and 2-3m for single storey houses." The objective of this includes objective 4, to "provide privacy and soften the visual appearance when viewed from the street and from the neighbouring property." He opines that due to the location of the retaining walls, their visual impact cannot be softened by landscaping, contrary to the objective of the control. 4. There is no evidence relied upon by Ms Liu that contradicts this evidence concerning the adverse visual impacts of the retaining walls. Evidence concerning the breach of the KDCP 2012 controls concerning earthworks 1. Controls 3, 5 and 9 of Part 21.1 of the KDCP 2012, which concerns earthworks and slope, require: "3 Landscape cut or fill should not be more than 600mm above or below natural ground line. … 5 Existing ground level is to be maintained for a distance of 2m from any boundary. … 9 Excavated and filled areas are to be constructed so as not to redirect or concentrate stormwater or surface water runoff onto adjoining properties." 1. Mr Richardson's evidence is that the retaining walls and the fill do not comply with these controls, and that there is no justifiable reason for fill of up to 2m in breach of these controls. He opines that: "It is considered that the open space associated with the dwelling facilitated under DA0604/15 was usable and of high amenity, as it orientates north, is improved with a swimming pool and benefits from a generous area of lawn that allows passive recreation. Filling of this area to 2m in height was not required for amenity reasons." The plans approved by the construction certificate 1. As set out above at [19], the construction certificate forms part of the development consent and prevails over the development consent plans to the extent of any inconsistency. The plans approved by the construction certificate are listed as the construction certificate attachments. This includes the Architectural Plans by Archian Architects (Drawing numbers A001, A101, A102, A121, A122, A131, A132, A133), which have been stamped by the certifier from ACE Building Approvals. 2. The plans approved by the construction certificate also includes the structural engineering details by Allied Consultants (drawings 1 to 5), and the Stormwater Drainage Plan by Allied Consultants (drawings 1 to 3). These have not been stamped with an approval stamp, but were attached to the construction certificate application and are Revision B plans dated 30 April 2016 and 29 September 2016 respectively. That these are the approved plans is supported by the Structural and Stormwater Design Statement from Allied Consultants dated 29 September 2015, which identifies these dates and revision numbers, and is also attached to the construction certificate. These documents are contained within Attachment B to Ex 3. 3. Pursuant to s 6.4(c) of the EPA Act, an occupation certificate, when issued, "is taken to be part of the development consent to which it relates". The Occupation Certificate issued on 21 April 2020 therefore forms part of the development consent for the site. It sets out a list of attachments. However, none of those attachments appear to contain a stormwater design or architectural plans that might differ from what was approved by the construction certificate. 4. There are two sets of drawings that Ms Liu erroneously relies upon. The first is contained in Ex C, and are the drawings prepared following the issue of the construction certificate. They are marked in the issue notes as "revised for construction". These are the Revision C, D and E plans that Ms Liu says are the correct plans. However, the revision dates for these drawings post-date the construction certificate and do not constitute an approval for anything depicted therein. Although those plans show the specifications for the purposes of carrying out the construction work, there is no legal basis upon which they are incorporated into the approval of the construction certificate. 5. The second set of drawings Ms Liu erroneously relies upon is three plans that are contained in Ex B, which are prepared by Archian Architects and appear to show the works as executed on the site. Although this set of plans purports to be the Revision A architectural plans, they are not stamped by the certifier and the plot date on the side of the plans is 29 May 2019. These plans therefore post-date the issue of the construction certificate, and there is no basis upon which they constitute an approval for the work that has been carried out on the site. In oral evidence, Mr Richardson gave evidence that these plans were likely received by the Council in the course of their correspondence with Ms Liu concerning a Notice of Intention to issue an order. 6. As such, I cannot accept the submission by Ms Liu that the expert evidence relies on the wrong drawings. It is clear that the plans relied upon by Mr O'Connell and Mr Richardson were those approved by the construction certificate. The retaining walls and fill are not authorised by the development consent 1. Contrary to the arguments put forward by Ms Liu, neither the development consent nor the construction certificate authorise the construction of the retaining walls or the fill. I find that the retaining walls are not authorised by the development consent, and that the rear yard of the site has been filled to a level not authorised by the development consent. 2. Firstly, I accept Mr O'Connell's evidence that the absorption trench was not built in accordance with the approved stormwater drainage plans, given that it was built at a higher level than indicated on the stormwater drainage plan. In accordance with the stormwater drainage plans prepared by Allied Consultants and approved by the construction certificate, the absorption trenches that are within the rear yard are sub-surface trenches. This is clearly seen in the absorption trench detail (Drawing 3 Rev C), which shows the surface level of the soil of the absorption trench as 138.20 and the grated access at 138.70. The levels of 138.20 and 138.70 are consistent with the natural ground levels shown on the survey (dated 4 August 2015), the landscape plan (dated 6 September 2016) and the approved construction certificate plan for the ground floor (Archian Architects A101 Issue A stamped by the certifier). It is apparent from the site inspection, and from the evidence of Mr O'Connell, that the land has been filled and that the absorption trench was not built at the approved level. I accept Mr O'Connell's evidence that, on this basis, the certification that it was installed in accordance with the plans should not have been given. 3. Secondly, the retaining walls are not required for the operation of the stormwater drainage system. I accept the evidence of Mr O'Connell in that respect. I accept his evidence that there is no engineering requirement to provide fill and retaining walls for the successful operation of the stormwater drainage system, and that the provision of the retaining walls may actually undermine the proper functioning of the stormwater system, as it will interrupt the subsurface operation of the absorption trench to disperse water along the contours of the land in a north-eastern direction towards the reserve. There is therefore no basis upon which it could be concluded that the stormwater drainage plans required the construction of the retaining walls. 4. Thirdly, the inclusion of the "1.8m high boundary fence" in the architectural plans approved by the development consent does not authorise the construction of a retaining wall along the same boundary. A boundary fence is not a retaining wall. Further, the fence details and the fence footing detail (Drawing A132 and A133), are approved in the construction certificate and do not depict a retaining wall. Although there is an inconsistency between the notation of a 1.8m boundary fence and the fence detail height of 1.2m, this inconsistency does not give rise to any approval for a retaining wall. 5. Fourthly, I accept that the rear yard has been filled to the extent shown in Ex B, to an approximate level of 139.58 AHD, which is not authorised by the development consent. The filling of the land is also readily perceived from the site inspection, at which it was apparent that the land has filled in the area retained, but has not been filled in other areas. I do not accept that the survey report relied upon by Ms Liu (Ex E) contradicts this evidence of the filling of the land. The natural ground levels of the rear yard are clearly shown in the survey dated 4 August 2015 (Ex 3 Attachment B). The post-development levels of the rear yard are clearly shown on the architectural and landscape plans (Ex 3 Attachment B), which form part of the construction certificate approval, and are consistent with the natural ground level of the rear yard. There is no basis upon which it could be concluded that the consent authorised the change to the rear yard ground level by filling it to the extent that has occurred. 6. Finally, the "typical detail" for retaining walls, which is contained on the construction certificate plans, is not sufficient to establish that there is approval for the construction of the retaining walls. None of the approved plans that form part of the development consent or the construction certificate depict a retaining wall on it. Accordingly, neither the development consent or construction certificate authorised their construction or the filling of the land to increase the levels of the rear yard. The retaining walls and fill are not exempt development 1. Part 2 of the SEPP ECDC sets out development standards for certain types of development, which, if complied with, means that that type of development can be carried out without requiring development consent. This is referred to as exempt development. 2. The development standards for earthworks, retaining walls and structural support are as follows: 2.30 Development standards The standards specified for that development are that the development must— (a) not be a cut or fill of more than 600mm below or above ground level (existing), and (b) be located at least 1m from each lot boundary, and (c) if it is carried out, constructed or installed in a heritage conservation area or a draft heritage conservation area—be located in the rear yard, and (d) be located at least 40m from a waterbody (natural), and (e) not redirect the flow of any surface water or ground water or cause sediment to be transported onto an adjoining property, and (f) if it is a retaining wall or structural support for excavation or fill, or a combination of both— (i) be not be more than 600mm high, measured vertically from the base of the development to its uppermost portion, and (ii) be separated from any retaining wall or other structural support on the site by at least 2m, measured horizontally, and (iii) be located at least 1m from any registered easement, sewer main or water main, and (iv) have adequate drainage lines connected to the existing stormwater drainage system for the site, and (g) if the fill is more than 150mm deep—not occupy more than 25% of the area of the lot, and (h) if the fill is imported to the site—be free of building and other demolition waste, and only contain virgin excavated natural material (VENM) as defined in Part 3 of Schedule 1 to the Protection of the Environment Operations Act 1997, and (i) if the land is in a rural zone—not be fill of more than 100 cubic metres on each lot. 1. If the earthworks, retaining walls and structural support comply with these standards, the development is exempt development and does not require development consent. 2. However, the retaining walls on the site and the filling of the site do not comply with these development standards. Specifically: * The fill on the site involves a fill of more than 600mm above the ground level, contrary to subcl (a), and it is not known that it only contains virgin excavated natural material, contrary to subcl (h). * For all of the four retaining walls, they potentially redirect the flow of surface water or ground water, contrary to subcl (e), and they provide structural support for fill without it being known whether they have adequate drainage lines connected to the existing stormwater drainage system, contrary to subcl (f)(iv). * For the retaining wall furthest to the east, which is up to a height of 2m and longer than 20m, it runs along the eastern boundary contrary to the requirement in subcl (b) to be located at least 1m from the lot boundary, and it provides structural support for fill and is greater than 600mm high contrary to subcl (f)(i). * The retaining wall that is 5m from the rear boundary (and runs parallel to the rear boundary), intersects with the eastern boundary and is therefore non-compliant with the requirement in subcl (b) to be located at least 1m from the lot boundary, and it provides structural support for fill and is of a height of around 2m, which is greater than 600mm as required by subcl (f)(i). * The retaining wall along the rear boundary is not compliant with the requirement in subcl (b) to be located at least 1m from the lot boundary, and is potentially greater than 600mm in height along part of its length but its precise height is not known. * The retaining wall that runs between the retaining wall along the rear boundary, and the retaining wall parallel with the rear boundary, intersects with the rear boundary and is therefore non-compliant with the requirement in subcl (b) to be located at least 1m from the lot boundary, and it provides structural support for fill and is of a height of around 900mm, which is greater than 600mm as required by subcl (f)(i). 1. Further, earthworks, which includes the filling of land that alters the ground level (see the Dictionary to the KLEP 2015), requires development consent pursuant to cl 6.2 of the KLEP 2015. The order should remain 1. In circumstances where the construction of the retaining walls and the filling of the rear yard required development consent, and the development consent DA 0604/15 and construction certificate PC16337 relied upon by Ms Liu did not incorporate those retaining walls and fill, the legislative basis is met for the issue of a development control order in the form of a Compliance Order, pursuant to Item 11 of Part 1 of Schedule 5 of the EPA Act. For the following reasons, I am satisfied that the order the subject of the appeal should remain, but ought to be modified as proposed by the Council. 2. Firstly, I do not accept the submission of Ms Liu that the retaining walls and the fill are required for the operation of the stormwater drainage system. Instead, I accept the evidence of Mr O'Connell that there is no engineering requirement to provide fill and retaining walls for the successful operation of the stormwater drainage system, and that the retaining walls are instead likely to hinder the dispersal of water from the absorption trench system. 3. Secondly, I accept the evidence of Mr Richardson that the retaining walls and the filling of the rear yard are not required for the amenity of the occupants of the dwelling. I accept his evidence that the open space associated with the dwelling was usable and of high amenity, as it orientates north and benefits from a generous area of lawn, and filling of the area to 2m above the natural ground level was not required to maintain that amenity. 4. Thirdly, I accept the evidence of Mr O'Connell that there is a risk of failure of the retaining walls in the absence of the evidence establishing that the retaining walls were designed by a suitably qualified and experienced engineer in a manner that allows for the drainage of water. The certifications relied upon by Ms Liu are not adequate to establish that the retaining walls were so designed. The additional certification relied upon by Ms Liu, contained in the email 18 February 2021 and attached to her submissions in reply, states that they will "function as per design intent" without any indication of what constitutes the design intent, and, as such, it is not sufficient to establish that the retaining walls have been designed by a suitably qualified and experienced engineer with sufficient drainage to accommodate the dispersal of water from the absorption trench system and to relieve the hydrostatic pressure created from the dispersal of that water. In the absence of such evidence, I accept Mr O'Connell's evidence that interruption of subsurface flows from the absorption trench by the retaining walls can lead to an accumulation of water at the back of the retaining walls, which can create hydrostatic pressure and lead to the failure of the walls. 5. Fourthly, I accept the evidence of Mr Richardson that the raising of the levels of the rear yard has created an adverse visual impact, which is readily perceived from the public domain. The resulting structure, with both the retaining wall along the eastern boundary and the fence, is around 4m in height is visually dominating when viewed from the public domain to the east. I accept his evidence that this has a dominant effect that far exceeds the effect of a typical lightweight boundary fence. 6. Finally, the fact that there may have been inspections by representatives of the Council for the purpose of approving the positive covenant, or by a principal certifying authority for the purpose of the occupation certificate, does not mean that there has been any operative approval of the retaining walls or the fill. 7. For these reasons, I accept that a compliance order should be issued to ensure that the site is brought back to compliance with the development consent and the construction certificate. Rather than leaving the terms of the current order in place by confirming the order, I accept that the order should be modified, as sought by the Council. There is no evidence to support the submission of Ms Liu that the soil was from the site itself, and the modified order proposed by the Council will ensure that the fill that is on the site is not contaminated or is remediated if contaminated, and that it will be disposed off-site appropriately. It will also ensure that there is a clear plan of works for the demolition of the retaining walls and the levelling of the site. 8. The levelling of the site will inevitably involve restoring the stormwater system to what was approved by the stormwater plans such that the pit surface level of the absorption trench is consistent with the natural ground level as it was before the land was filled. This is in accordance with the levels shown on the approved construction certificate plans, that is, the stormwater drainage plans by Allied Consultants (drawings 1 to 3) Revision B dated 29 September 2016 and the absorption trench detail contained therein (drawing 3). The outcome of the appeal 1. As I have determined that the order should be modified, the appeal is upheld insofar as it allows the Court to make the orders to modify the development control order. 2. In addition to modifying the order in the manner sought by the Council, I consider it would be useful to specify timeframes around the carrying out of testing and the provision of a remedial action plan, in addition to the timeframe specified for the demolition of the retaining walls and the removal of the fill. I have therefore made changes to the proposed modified order sought by the Council to specify a timeframe of 14 days for the carrying out of testing, and a further 21 days (35 days from the date of the order) for the preparation of a remedial action plan, if required, and the construction management plan. 3. I have also made changes to order 1 of the terms of the order to ensure that it clearly incorporates all of the retaining walls and fill earlier referred to in the order. 4. In addition, Ms Liu will be required to install the stormwater drainage system as it was approved, in accordance with the stormwater drainage plans by Allied Consultants (drawings 1 to 3) Revision B dated 29 September 2016 such that the pit surface level of the system installed is consistent with the absorption trench detail contained therein (drawing 3). This will resolve her concern about the impacts of the removal of the fill around the area where the absorption trench system is currently installed. This work will also need to be certified by an independent qualified engineer, that is, someone other than Allied Consultants. These requirements have also been incorporated in the final modified development control order. 5. All of these changes are reflected in Annexure A, which comprises the final modified development control order the subject of the orders below. 6. The Court orders that: 1. The appeal is upheld. 2. The development control order issued by the respondent on 23 October 2019 is modified in accordance with the terms of the modified development control order in Annexure A. 3. Exhibit 2 is returned. …………………….. J Gray Commissioner of the Court Annexure A (110433, pdf) ********** DISCLAIMER - Every effort has been made to comply with suppression orders or statutory provisions prohibiting publication that may apply to this judgment or decision. The onus remains on any person using material in the judgment or decision to ensure that the intended use of that material does not breach any such order or provision. Further enquiries may be directed to the Registry of the Court or Tribunal in which it was generated. Decision last updated: 25 February 2021