Buying a run-down property to renovate is as much a pricing exercise as a building one, and the mistakes that blow budgets almost always happen before a single trade sets foot on site.
None of these mistakes are exotic. They repeat across nearly every doer-upper we're asked to quote for, which is exactly why they're worth setting out plainly rather than learning the hard way.
Budgeting from the kitchen backwards
It's natural to walk a rundown house and start imagining the finished kitchen, but pricing a project from its most visible, most desirable room backwards is how contingency disappears before the roof has even been looked at. The correct order is structure and weathertightness first, services second, fabric and finishes last — and the budget should be built in that order too.
A buyer who allocates a generous kitchen budget early, then discovers a chimney needs rebuilding or a roof needs stripping, is choosing between a compromised kitchen and an overspend. Pricing the unglamorous items first removes that choice before it has to be made under pressure.
Treating a survey caveat as a footnote
Survey reports hedge their language for good reason, and phrases like 'further investigation recommended' or 'monitor for movement' get read by buyers as minor when they can represent five-figure repairs. Every caveat in a survey deserves a specific follow-up quote before exchange, not after completion when the leverage to negotiate the price has gone.
Where a seller won't allow further investigation before exchange, that itself is worth factoring into the offer, since it means pricing the worst reasonable interpretation of the caveat rather than the best one.
Starting cosmetic work before the roof is proven sound
It's tempting to get a room finished quickly for morale, or to make a spare bedroom liveable while the rest of the house waits. Decorating a room under a roof that hasn't been confirmed sound is a common way to pay for the same plasterboard twice, once now and once after a leak.
The sequencing discipline that avoids this is simple: roof and structural investigation and repair come first, then services, then fabric and decoration follow once nothing above or behind them can still move or leak.
Access and services assumptions
Doer-uppers are frequently vacant or semi-derelict for a period before purchase, and utilities are sometimes capped off, disconnected or simply unknown in condition. Buyers who assume services can just be switched back on sometimes find a full rewire or a new supply is needed before any other trade can safely start.
Checking the condition and capacity of the electrical supply, water connection and drainage before exchange — or at minimum, pricing a worst-case renewal — avoids an unbudgeted first-fix bill landing in week one.
Underestimating the cost of finding out
Every doer-upper has a stage where opening up walls, floors and roof voids reveals the real condition behind the visible one, and this discovery process itself has a cost in time and labour before any repair even starts. Buyers who price only the repairs they can see, with nothing set aside for investigation, run out of contingency at the exact point they need it most.
Building an allowance for opening-up and investigation into the very first stage of the programme, separate from the repair budget itself, is what stops this stage from feeling like an ambush.
Common questions
How much contingency should a doer-upper budget carry?+
There's no single figure that fits every property, but a doer-upper priced with no contingency at all is a common and avoidable mistake. The right allowance depends on the age, construction and how much has already been surveyed versus assumed.
Should I get a specialist's opinion before exchange or after?+
Before, wherever the seller allows it. Once exchanged, any finding becomes a cost you simply have to absorb rather than a factor you can negotiate on price.
Is it a mistake to live in the house while it's being renovated?+
It isn't a mistake in itself, but it does change the sequencing — some structural and services work is much harder to do safely around a family in residence, and that should be planned for rather than discovered mid-project.
Get a written scope and sequencing review before you commit
We'll walk the property, flag what needs investigating before exchange, and set out the right order of works with a free written quote.