Exclusive: Darren Palmer reveals the biggest mistake you can make while renovating a property

They say that any renovation project will take 20 per cent more time and money than you plan for.

But just like most things that happen to 'other' people, I thought that surely won't be the case for me – and oh, how wrong I was.

It's not that materials blew out or labour expenses were more than expected. Sometimes that does happen, but in my project we'd planned around both of those occurrences.

No, in my case the extra time and money spent can be attributed to one thing and one thing only – my own desire for perfection.

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Changing your renovation plans could be considered the biggest mistake you could make when renovating a house, but there's more to it than that.

There's a deeper issue – the desire to make things 'perfect'.

That desire, instead of making choices based on what is right, most appropriate or most affordable is by far the biggest mistake that anyone can make when renovating.

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Wanting to achieve perfection is a great attribute that can drive you towards a great outcome. When renovating, however, predictability and contractual stability is paramount to delivering a project on time and on budget.

When 'desires and wants' start to overtake the rigidity that is documented in response to the project's 'needs and requirements', you drive your renovation into uncharted territory, a tumultuous sea of unexpected labour, time, certification and approval costs.

You derail your renovation off its tracks and wave goodbye to nice predictable deliverable milestones paced regularly like train stations along a predetermined and agreed network.

You trade off the efficiency of say, the Japanese approach to transit, and end up with something far less predictable and efficient, akin to the ones we're all too aware of in some major Australian capital cities.

If predictability and efficiency is what you're aiming for in a renovation – and those two things above all should definitely be what you're aiming for – then changes to scope are what you need to try and avoid.

If you're looking to have a successful renovation project the process should look something like this...

Write down what you want to achieve

Outline everything you want to achieve and the areas that project that will encompass. Work out the full scope of everything you want to achieve, all the challenges to be solved and all the improvements to be made. Be comprehensive and sensible. Reach for the stars but also consider your available time, budget and resources.

A project may be divided into phases depending on time and available funds. You might have a large plan that is sensible to carry out in parts, and that's just fine. If you're planning to carry out parts of a scope of works at different times, make sure that where you intend to stop your phases makes sense in terms of the work required to continue into the next.

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A perfect example of this is in my own project I had to remove a third of my house and rebuild it. That's where the scope stopped but it also meant that when we went onto phase two, we would have to redo the ceiling and flooring of part of the phase one works.

That meant a part of the phase two works had to be integrated into phase one, meaning the contracted works that were based on the phase one scopes where now subject to new and unplanned costs of works, otherwise known as variations, otherwise known as what you want to avoid.

Have a clear budget

The best thing about being clear and prescriptive in your brief is that you can put your scope of works out to tender and then assign the project to the right builder or contractors.

You can plan your funds and align them to the milestones that are outlined as deliverables in your contract, which means the smoothest process for both client and builder.

When you create a new or additional scope however, you have to consider that there are knock-on effects to the original timings and costs.

The variations don't only have financial costs they have consequences for how long you might be out of your home and how much stress for how long you will be putting yourself and your loved ones under. 

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Think about your resources

When it comes to resources you need to think of not just suppliers, contractors, time and budget but also energy, mental focus and mental and physical wellbeing.

When you're consuming resources that you hadn't planned for, whether that be finding extra trades or craftspeople to deliver a new and exciting vision, or if it means finding the internal fortitude to move house AGAIN, there's going to be a cost.

When you plan for something, things will always need to be adjusted but at least you've planned for them.

When you add things to your project you need to brace yourself for the consequences as the challenge of dealing with a renovation increases unpredictably and often exponentially.

That all said, what we're saying here is that a renovation is a tough thing to carry out and even tougher when you want for bigger, better or more.

That desire ironically is often what is required to elevate a result from something that you're satisfied with to something that exceeds your expectations or sometimes even your wildest dreams.

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