It starts with a number. A clean, neat figure in your head. Something you’ve scribbled on the back of a receipt or typed into your notes app at 2am.
And then?
Then the builder starts talking. And that number grows teeth.
Renovation costs are like concrete – they set fast. The trick is to keep control before they harden into something you can’t afford.
Here’s how to stay one step ahead, says Steve Walker from www.a2building.co.uk.
Decide what matters most – and stick to it
You want it all: the big sliding doors, the walk-in shower, the heated floor, the handmade tiles.
But if your budget won’t stretch that far, you need to choose.
Pick one or two things that matter most.
Be honest about the rest.
Luxury costs. But so does changing your mind.
Get a fixed quote, not a vague estimate
Some builders like this Wimbledon company, quote like politicians. Big smiles, round numbers, no detail.
Don’t fall for it.
You want a written quote that lists what’s included, how long it’ll take, and who’s doing what.
If it’s not in writing, it doesn’t count.
And when costs change, which they will, you’ll need something to refer back to.
Plan for the unexpected
There’s always something.
Old wiring. Rotten floorboards. A pipe that no one knew was there.
Set aside 10–15% of your budget for surprises.
Call it your “don’t panic” fund.
It’s the difference between rolling with the problem or putting the project on hold.
Keep a running total – every day
This isn’t a guessing game.
You should know, at any point, how much has been spent and what’s left.
A notebook works.
So does a spreadsheet.
It doesn’t need to be fancy.
But if you wait until the end to do the maths, the numbers will hit like a brick through glass.
Don’t change your mind halfway through
Builders hate it.
Suppliers hate it.
Your wallet really hates it.
Every time you change your mind, it slows the job and adds cost.
Choose your tiles. Choose your lights. Choose your layout.
And don’t second-guess yourself unless something’s wrong.
Reuse what you can
Not everything needs to be new.
Can the original doors be sanded and painted?
Can the kitchen carcass stay, with new fronts and handles?
You’d be surprised how much you can keep if you look at it with fresh eyes.
Be wary of DIY extras
Painting one room might save you money.
Building your own fitted wardrobes probably won’t.
Unless you know exactly what you’re doing – and have time to do it – DIY can cost more in the end.
Let your builder do what they’re good at.
Focus on the jobs you know you can finish.
Avoid last-minute shopping trips
That £300 tap you saw on Instagram? It might look nice.
But ordering it late, with next-day delivery, and a plumber waiting on site, will cost more than you think.
Choose your materials early. And stick to the plan.
Watch out for “while you’re here…”
This is how budgets burst.
“Oh, while you’re here, could you just move that wall?”
“Could you re-tile the bathroom too?”
Every extra job adds time, materials, and money. If you want more done, that’s fine. Just don’t pretend it’s still part of the original plan.
Hire the right people
The wrong builder will smile, nod, and charge double.
The right one will ask hard questions.
- Check references.
- Read contracts.
- Ask about insurance.
Paying a little more for someone honest might save you thousands later.
Final Words
Renovations don’t go wrong overnight.
They go wrong slowly – one small change at a time.
But if you ask the right questions, plan properly, and stay involved, you’ll get the home you want without the nightmare you didn’t.
