usually the biggest set back is to the front of the house (not a small open porch area) and the garage usually has to be further back but the actual amount can differ in different areas..a local professional would know all this information immediately .. a rear extension can vary depending on how close the neighbours are on all sides, how big the extension will be, what shaope is it (eg a long narrow extension across the whole of the house or a square extension that almost reaches the back fence?) is it all inside space and/or include open areas, how much back garden will be left over and how much of the whole block the old house plus extension will use..we usually make a rough plan of what we think would be ideal, invite comment from the neighbours and make an appointment to discuss with local council building inspector and usually received useful advice as long as we make a dummy development application to take with us so that we have all the basic information they need including a copy of original house plans and a scale drawing of the proposal (including proposed setbacks) They can't/won't give you a final answer until they receive a formal application but at least they should help you avoid the impossible

thanks oklouise!

Hi Havana007,

Sorry for the late response but I'm an Interior Design and my husband is a Builder and we own Khadye Design and Construction. If you need any helps with boundaries, design, construction etc etc feel free to give me a call on 0411439768. We can hold your hand throughout the whole process and do all the design, drafting, engaging of the certifier/engineer/surveyor and of course the build.

Thanks!

Michelle