'How much did that set you back?' was the first question out of my Grandpa's lips anytime someone close to him was showing off their new purchase.

You could see the pride drain from the new owner's face, especially as their response was typically followed by, 'Phewww... that's pretty steep!'

Obviously, no one bothered to tell dear old Pa that's a rude question - even if it's the question we all want to ask!

How much you paid for something can be a touchy subject - especially when it comes to big-ticket items like houses. I try to include the building budgets of projects whenever I can because I know how helpful it can be to potential builders and renovators. But unfortunately many people are reluctant to disclose their building budget - presumably, so people don't think, 'Phewww... that's pretty steep!'

But don't worry, I have a few tricks you can use to get a pretty good estimate of a project's building budget.

The cost to build or renovate a house can vary significantly depending on where you live. On an international scale, an American would spit-take their Budweiser in your face if you told them how much it costs to build in Australia. But our average wage is higher and our isolation and small population mean that materials are generally more expensive too.

At a more local scale, someone building in inner-city Melbourne or Sydney will pay more than someone building on a suburban site or in a regional city. A difficult site, like a heady slope, difficult soil conditions, or a bushfire (BAL) rating are also sure to increase the build costs. And if you live in a really remote part of the country you can expect to pay more too. Put simply, it gets complex. That said, there are a few guides to give you an idea:

I like to use this guide by Cordell, a well-known construction and estimating company. This calculator also offers a good estimate. Really though, your best option is to consult with a professional, an architect, building designer or builder can give you a clearer idea of how much it will cost to build and whether your budget is realistic for your expectations.

Any tips on calculating how much it will cost to build? Let us know in the comments below...