Browse Forums Building Standards; Getting It Right! 1 Mar 30, 2016 4:06 pm Hi all, I have a few questions about retaining wall standards: I am looking at flattening out a portion of our backyard which slopes down into a bush reserve. There is currently about a 4m wide strip of "flattish" ground from the rear wall of the house after which it starts sloping away at a steeper rate. I want to build up about 1-1.5 metres of this steeper slope area with fill and then retain to create a wider flat area we can then turf and fence in for the kids to play in safely. I am still working out details with our landscaper but it looks like we should be able to use up to 600mm high walls, and thus stay within exempt development criteria, however there MAY be a necessity to go higher than this in some parts which would then push us into CDC (NSW) territory. These works are not for the purpose of constructing a dwelling, therefore I have been looking at clause 3.29 of the NSW SEPP which is shown below in italics: (5) Retaining walls and structural support Support for earthworks that are more than 600mm above or below ground level (existing) and within 1m of any boundary, or more than 1m above or below ground level (existing) in any other location, must take the form of a retaining wall or other form of structural support that: (a) has been certified by a professional engineer, and (b) has adequate drainage lines connected to the existing stormwater drainage system for the site, and (c) does not result in any retaining wall or structural support with a total height measured vertically from the base of the retaining wall or structural support to its uppermost portion that is: (i) more than 1m in height and within 1m from a side or rear boundary, or (ii) more than 3m in height in any other location. (6) Any excavation or fill that exceeds 600mm above or below ground level (existing) requires a retaining wall or structural support that must be: (a) constructed in accordance with subclause (5), and (b) designed so as not to redirect the flow of any surface water or ground water, or cause sediment to be transported, onto an adjoining property, and (c) separated from any retaining wall or other structural support on the site by at least 2m, measured horizontally, and (d) installed in accordance with any manufacturer’s specification. Note. Fill and excavation that is not associated with a building may be exempt development under clauses 2.29 and 2.30. Any breach of the 600mm height would be less than 1m and more than 1m inside our boundary, therefore am I correct in interpreting Clause 5 and the Note that this type of wall would then fall under exempt development because it is for landscaping and not dwelling construction purposes? If it is less than the 1m requiring engineering approval do I still need to submit a complying development application? My second question is about the type of wall. It is easy to use timber or concrete sleeper with posts, however a more natural choice for our bush outlook would be to use the large sandstone "stacked boulder" type, which is very common in the Castle Hill/Glenhaven area of Sydney we live in. We also have quite a few of these boulders scattered around the backyard which could be used up before buying more stone and reduce costs. What sort of engineering is required for this type of wall? A lot of them appear to be just very large boulders stacked on each other and using their weight as a anchor rather than concrete etc. Has anyone built one of these before? Would be glad for any advice. Re: Retaining Wall Query - Exempt or Compying Devemopment? 2Jun 24, 2016 8:34 am For anyone in NSW I recommend using this website to check the planning rules for Exempt Developments before you call anyone at your council. You plug in your address and it will tell you which rules apply. http://interactivebuildings.planning.nsw.gov.au/ Thank you again Simeon.. I will call my certifier for that. Have a good day 4 5197 2 7209 There is no reason why building contract reconciliation cannot be done prior to handover, if the builder won't do it get someone to do it for you. Why would you pay for… 3 6690 |