If the neighbors approve, you will be able to build as close to the boundary as 500mm. If your Patio length is longer than 9.5 mtrs you can build to 1500 mm to the fence line without getting neighbors comment. You are able to cover up to 50{64a571fd96de0bb491712e3a64edb04c046ff08c0c0844bd0668059a859e86a0} of your block without restriction, after this you may cover up to 50 sqm. (as per the R-codes).