As a ballpark starting figure use around $1800 - 2000 per square metre. This just a ballpark figure to use as as starting point and can easily vary either side. So for $150k for that size dwelling is only around $600 per square metre...... Contact a local designer (the good ones understand budgets and costings) and start from there. Material and product choices will vary the cost to construct greatly so keep that in mind. Building costs are always increasing not going down.

Thanks Clipsal. I like to avoid putting more into landfill as much as possible especially when you have great "bones" to work with. I believe the brushed chrome electrical cover plate is from you guys. I've recently used your products on another jobs. :) Detail, details - make a HUGE difference.

Regarding the quote. An electrician is a supplier of goods and services, therefore 10% GST is charged on the full invoice amount. The quote shows that the GST of 10% has been charged on total amount, which is correct. So…..why has the quote stated that gst is for parts only? “No gst charged on labour”. This is incorrect and gst is charged on the full invoice, as the calculation on the quote shows. So…does this mean that they have not charged you the labour component? Or, the electrician doing the quote just doesn’t understand the GST system. GST is charged on all goods and services. When the electrician pays their employees this is completely different and has nothing to do with GST.

I would work out how many square metres you are adding and renovating. Then times that by $5000 per square metre. But there are so many variables. What is the house made of, brick or timber, what is the roof line to be able to be adaptable for an extension? Are the floors concrete or wood, to accommodate changes in plumbing? What specifications are you after, low, middle range, or fancy? Is the land flat, do trucks have good access…..?? Etc etc. only a few years ago I would have had said $3000 per square metre, but now…you need good firm quotes….and good firm time lines….so that is why I have said a very unsure $5000 per square metre.