If you go down to the woods today…

JD recently received an email from a customer who was not happy that there had been a “massive cost blowout” on their project.  While the cost of the project was now larger than originally anticipated, this was because there had actually been a “massive scope of works blowout”.  That is, as the job had gone one, they’d asked for more work to be done.

Customers often ask for a fixed price quote, and that’s understandable as people like to know how much their job is going to cost. However, unless they’ve got a comprehensive scope of works, it’s really easier to keep pointing at things around the house and say, “can we just do that? And that. And that.” Before you know it, you’ve gone from a new set of bifolds in the living room to a revamped kitchen and pergola as well. And the costs go up accordingly. (Remember when we talked about the fact that “just” is a very nasty little four letter word that you really shouldn’t use on a building site?)

In addition, while builders can make a reasonable assumption about what to expect when they start working on a house, there are often a fair few surprises lurking beneath the walls and floors.


In older houses particularly, it’s hard to tell what state the wiring is in until you actually start pulling things apart. If you lucky, the house was rewired in the not-too-distant past. If you’re not, the whole house may need to be rewired. Safety wins every time.


A builder can make a guess as whether asbestos has been used in a house by the age of the building (asbestos has not been used in building since the 1980s, so if your house was built prior to that, there may be asbestos) but again, they won’t know for sure until demolition begins. Asbestos removal needs to be undertaken by a professional – this is not a weekend DIY project – and costs will vary depending on how much there is.

Rotten timber 

Gyprock and paint can cover a multitude of sins when it comes to rotten or termite-riddled timbers (remember the termite buffet?), so if damaged timbers are uncovered during the building process they’ll need to be replaced – there’s no fudging this one.

Dodgy building

Everything might look fine from the outside but even if you’ve had a building inspection there could be problems that don’t turn up until you really start investigating. A friend of ours had to entirely reclad their house as incorrectly installed cladding started literally peeling off the walls 18 months after they bought it. The problem really showed up when JD and his crew were there working on a new deck and staircase. Once the problem had been identified they had no choice but to fix it. You never know the quality of workmanship undertaken by a previous builder unfortunately.


If you’re renovating, it’s wise to allow around 20 percent of your budget to allow for contingencies such as these. Best laid plans can come unstuck quickly when hidden problems rear their head. And make sure you use that budget buffer for unavoidable problems, not paying for things that you “just” decided had to be done as you were going alone. Prepare a thorough scope of works before you start so that any budget blowouts really are unexpected ones.

Have you had a “scope of works blowout”? Do you live in an old house that might be hiding some problems? What do you wish you could just do at your place?

Teaming up with Essentially Jess for IBOT


  • Hugzilla

    Aaaah, yes… We are just about to sign off on a complete bathroom reno with our builder today and this stuff scares me a bit. We are already at 20K just for labour alone and a big chunk of that is asbestos removal, with the scope for that to increase if necessary. Frankly, this is the first time we have renovated using professionals and we have been shocked at the cost. Like, really shocked.

    • Bec Senyard

      I was going to say $20,000 for labour? Then I read asbestos removal. It definitely inflates the labour costs for sure. It will be worth it in the end… x

    • alix@thebuilderette.com

      Yep, asbestos removal can be a big one – however prices really vary. Hope the reno goes well!

  • Bec Senyard

    You can never underestimate what can be found behind walls and under floors. We recommend if you’re taking the walls down, you should upgrade the plumbing – and in most cases it requires to be configured to suit the new fixtures. I’d love to renovate one day – just for the experience of doing it on my own house – but I know that I will possibly fall in love with looks that will blow out the budget.

    • alix@thebuilderette.com

      Thanks Bec – yep, updating the plumbing while you’re down there is an excellent idea.

  • Nicole @ The Builder's Wife

    This has also happened to us, now we quote for the extras, as the scope changes (As it nearly always does) and then have the client sign off on the cost for the extra work, as well as the new running job total. No more nasty surprises, no more yucky emails, and no more difficulties at the end of the job. I think 20% is a great contingency amount to have, there will always be difficulties in renovating, it totally makes sense to plan for them.

    • alix@thebuilderette.com

      Oh yes, we always get variations signed off. Trouble was in this case, the wife was signing off the variations but not telling her husband who only saw the final bill! Communication people – really, it’s just so useful! 🙂

  • Cathy@lifethroughthehaze

    We were very lucky when we did our renovations because we actually ended up with a refund lol! Which meant that the little jobs that cropped up like the shower tap leaking behind the wall and requiring a completely new pipe behind the tiles, installing my new dishwasher because my old one died and re-tiling our sunroom to match the bathroom extension so that the two rooms flowed together and didn’t look like an after thought. None of these things were in the initial scope of works because somehow there was extra in the budget which meant that even after the addition of all of these things we still came in under budget.

    I get really annoyed with people who blame the builder when in fact it was their additions to the scope that caused the cost blowout. Many, many years ago I worked for a high quality carpeting organisation and this type of thing would happen all the time. The scope of works would be tendered and accepted and then the client would change the quality of the floor coverings. Then they would argue about the cost!

    Why is everything always someone else’s fault?!

    • alix@thebuilderette.com

      Hi Cathy – sounds like you did well in your reno. Great work and yes, yes, yes to changing quality after you’ve signed off on an allowance. Not the builder’s fault if you decide you want more expensive carpet/tiles/lights than you agreed to. Always pays to be really thorough and realistic with your scope of works at the start.

  • EssentiallyJess

    I’ve never renovated but I feel like if we ever do, I’ve learnt lots about the process just from blog reading. It’s great. 🙂

  • JF Gibson

    I guess it’s a bit like any copywriting. You quote for a job and then the client wants to add this or that. I always quote and advise the clients of the costs whenever there are amendments to the scope of works. That way everyone knows where they stand. However, not as easy to do in the building game (my hubby’s a builder)!

    • alix@thebuilderette.com

      Hi – thanks for visiting. Snap! As I’m a writer married to a builder too – words much easier to change than brick walls. I had a client the other day who completey changed the brief on me – which is all fine, but it will cost you to do again!

  • Emily

    Great post. We undertook a massive renovation (under, up and out, then a remodel of the existing) and I thank the heavens every day that hubster is a builder and construction manager. The knowledge and the contacts were better than money!
    Meanwhile, the tales my husband comes home with of developers totally changing a project’s scope then acting outraged at the revised costs are hilarious! (For me. A nightmare for him!) #teamIBOT

    • alix@thebuilderette.com

      Hi Emily, thanks for visiting! Oh yes, it’s non-stop laughs when it comes to people changing things and then wondering why the price changed! 🙂 That sounds like a huge reno – you’re brave!!

  • Janet aka Middle Aged Mama

    I need to be stricter on this in my own business of building websites! When I provide a quote I have a clause that says the client will be advised if the project is likely to blow out by more than 10% …however I have yet to actually follow through …

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