One of the more frustrating things about refurbishment projects is that when there is a loss of profit, it is not always because of something dramatic.
Sometimes it is not one big disaster at all.
Sometimes it is a series of smaller mistakes, each of which may not look too serious on its own, but together they quietly chip away at the margin until, by the end of the project, what looked like a decent profit has become something much less impressive.
Very often, those mistakes come back to the same basic problem: not having a proper grip on costs before the project started.
That sounds obvious, but it catches people out all the time.
Part of the difficulty is that refurbishment costs are not fixed in the way many beginners hope they will be. They vary by area, by specification, by the type and size of property, by who you use, by how busy trades are, and by the condition of the property itself. A figure that was accurate eighteen months ago in one part of the country may have very little to do with what you will actually pay today in yours.
So one of the first mistakes people make is relying on figures that are too vague, too old, or too general.
They use a rough estimate they found online. They remember what somebody at the property network meeting said they paid for a kitchen or rewire a couple of years ago. Or they use figures from a different part of the country and assume they will translate neatly to their own area.
That is risky.
The only figures that really matter are current, local figures from people who actually do the work in your area.
Another mistake is failing to write everything down properly in the first place.
It is easy enough to remember the big obvious items. Kitchen. Bathroom. Decorating. Carpets. Perhaps central heating or rewiring if the property needs it.
But refurbishment budgets often start going wrong around the edges. Clearing out. Skip hire. Small remedial works. Plastering that turns out to be more extensive than you expected. Joinery. External repairs. Bits of making good at the end. The sort of things that do not always get the same attention at the start, but somehow still manage to turn up on the bill later.
That is why I think it is important to be slightly dull and methodical at the costing stage. Not glamorous, I know, but profitable tends to be.
Labour is another area where people can badly underestimate the true cost.
Materials are easy to focus on because you can see them and price them reasonably neatly. Labour can be more slippery, especially if several trades are involved over a period of time. But labour is a major part of the budget, and if you are casual about it the numbers can move against you quite quickly.
Then there is the question of your own time.
A lot of investors do not cost that at all, which I think is a mistake. If you are project managing the job yourself, your time has a value. If you are doing some of the work yourself (and mostly I do not think you should), your time has a value there too. Ignoring that does not make it free. It simply means you are not accounting for all the costs.
That matters because people often like the feeling that they are saving money, when in reality they may only be hiding some of the true cost from themselves.
The same applies to finance.
If you are borrowing to buy, there is an interest cost. If you are borrowing to fund the works, there is another cost there too. And even if you are using your own money, there is still an opportunity cost because that money could have been doing something else. If those costs do not appear in your appraisal, then your appraisal is incomplete.
And then, of course, there is the contingency.
This is one of the biggest areas where people kid themselves.
On virtually every project I have ever done, something has come up that was not anticipated at the outset. It is not a question of whether unexpected costs will arise. It is a question of how much they will be. That is simply the nature of refurbishment. Once you start stripping things out and looking more closely, you often find that there is a bit more to do than you originally thought.
Which is why leaving out the contingency because you want the deal to look better is such a bad habit.
I would far rather the figures looked a bit less exciting at the beginning than discover later that the margin only existed because I had ignored reality.
So what else can go wrong?
Usually, it is not one thing.
It is a rough estimate here, a missing item there, no proper allowance for labour, no real allowance for your own time, an optimistic assumption about how long the project will take, and a contingency that is too small or not there at all.
By the end, the profit has not disappeared because of one huge dramatic problem.
It has simply leaked away.
That is why I think one of the most useful habits you can develop as a renovator is to be slightly dull and thorough about costs before you buy. Get proper quotes. Write everything down. Include the awkward bits, not just the obvious ones. Allow for finance. Allow for the cost of your own time. Allow for contingency. And only proceed if the deal still works after all of that.
That may not feel very exciting, but it is one of the best ways I know of protecting your profit.
Here’s to successful property renovating.
Peter Jones (ex) Chartered Surveyor, author and property investor
www.thepropertyteacher.co.uk
By the way, I’ve completely rewritten and updated my course for 2026, The Successful Property Renovator’s Workshop — a comprehensive guide to renovating properties properly and profitably, based on my own experience across well over 150 projects over thirty years. For more details please go to: https://thepropertyteacher.co.uk/the-successful-property-renovators-workshop-2/