depending on finish it could be enough for the basic building without the kitchen (mid range new kitchen cabinets and appliances could be about $30,000+) but what about the rest of the house...??

should be enough but with a family of electricians and plumbers they should have contacts in the building industry who could give you a better idea about local costs but check with your local council as "doing it to lock up" may not include legal approval for your occupation certificate to allow you to move in to the house without a functioning kitchen etc (although in one reno we relocated the old kitchen (biggest cost was electrician and plumber to move the old sink and stove) to make a temporary functioning kitchen...received our occupation certificate and then moved into the house and installed a new kitchen much later!!)

I was thinking of a similar reno in Sydney and the cost was 300k minimum. 😒 and my hubby is an electrician. might move to SA!

@rosie acosta Cost per sqm will vary throughout Australia, but we are only taking marginally. First a renovation is going to be a custom build, I.E. there is no volume builder that can easily do these on their very thin margins.

So a custom build is easily twice the cost sqm, you the small builders that complete these don't have the buying power on materials that the big guys do. This makes a massive difference to start.

You do not know what you are going to find when working on an existing home. When you open up the roof or walls where it connects there are often hidden treasures (not in a good way) that need rectified or mean that design may not work as expected.

Finally there is than the questions of what spaces are to be in the addition, is it a kitchen, bathroom or simply a living area. Are you expecting any built in joinery in the spaces, these all add it the cost of the addition that can not easily be reduced to a $/sqm.

Often small (20-80 sqm) renovation that I have done with a kitchen, bathroom or both will begin at $4-5k sqm. So @afjp is much closer, a min of $300k could be more realistic.

You are best to speak with a local architect that does these type of renovation regular and they should be able to sit with, understand what you are looking for and help you set your budget. Please understand this is not the final cost, it is an expected budget and it should be reviewed a couple of time before the builder has been ask to give you a final cost.

Maintaining a project within budget is an ongoing task throughout design and construction. It is about consistent management of decisions along the way. There is less you can do about bringing the cost down when the project is in construction, it is the design Phase that this can happen, cheaply and easily.

$150k not a chance unless you owner builder and implement a lot of DIY. If you want a builder to coordinate and be under contract then factoring in builders margin and GST you'd be lucky to get it to lock up for $150K. $1800/m2 is volume build rates. Anything custom is $3000/m2 min and the less you do the higher the cost/m2.......Site establishment, rubbish removal, demolition etc costs always are underestimated. Think $20-30K before you even start, then stack up earthworks, concrete, plumbing rough in, framing, brickwork, windows, roofing and you're probably at around $120K raw. Add builder's margin and GST on top and you're at $150K. Then you have to finish it (plastering, carpentry finishing, joinery, painting, plumbing and electrical fit-off, fittings & fixtures, floor finishes, light fittings, heating/cooing, external peripherals & make-good) ...that's probably another $150K post-lock-up components )

Good luck! PD :)

www.pauldistefanodesign.com