Buying a house is probably the biggest purchase you will ever make. So it is a bit wild that so many people skip the survey, or go for the most basic option just to save a few hundred pounds. A survey is not a formality. It is the thing standing between you and a very expensive surprise six months after you have moved in.
Here are five things a good survey can catch before they become your problem.
Damp You Cannot See
Damp is one of the most common issues surveyors find, and it is also one of the sneakiest. A fresh coat of paint can mask a lot. What looks fine on a viewing can hide rising damp, penetrating damp, or condensation issues that have quietly been doing damage for years.
Left untreated, damp can rot floor joists, damage plaster, cause mould, and lead to far bigger structural issues down the line. Repair costs vary hugely depending on the cause and severity, but treatment alone can run anywhere from a few hundred pounds to well over £5,000. Catching it before you buy gives you the chance to renegotiate the price or ask the seller to fix it first. The HomeOwners Alliance guide to house survey red flags is worth bookmarking if you want to know what to look out for in a report.
Subsidence
This is the one that makes people's stomachs drop. Subsidence, where the ground beneath the property is shifting or sinking, can cause serious structural damage if it goes unaddressed. The tell-tale signs are diagonal cracks around doors and windows, sticking doors, and uneven floors, but these are not always obvious on a quick viewing.
Repair costs can range from around £5,000 for minor work up to £50,000 or more in severe cases. Even a mid-range fix for a three-bed semi can average around £12,500. Knowing about it before you exchange means you can make an informed decision rather than inheriting someone else's problem.
Roof Problems
Roofs are easy to ignore during a viewing because most people are not getting up there with a ladder. A surveyor will inspect the roof covering, chimney, gutters, and loft space for signs of damage, water ingress, missing tiles, or structural weakness.
A full roof replacement on an average UK home can cost anywhere from £5,000 to £15,000 depending on size and materials. Even smaller repairs add up quickly. Spotting roof issues early means you can factor them into your offer or walk away entirely if the scale of work does not make financial sense. Which? has a useful breakdown of what different survey levels actually cover if you want to understand exactly what you are getting for your money.
Electrical and Structural Issues That Affect Your Mortgage
Some survey findings do not just cost money to fix. They can actually affect whether your mortgage lender will proceed at all. Spray foam insulation in the loft is a classic example. It has become notorious for causing lenders to withdraw offers because it can hide roof defects and affect the structure's breathability. Outdated electrics, non-standard construction materials, and certain types of flat roofing can all raise flags too.
Finding this out before you are deep into the legal process saves you from a situation where your mortgage falls through at the last minute. If you are buying in or around South London, getting a specialist Bromley property surveyor like South Surveyors who know the local housing stock well makes a real difference here, particularly with older Victorian and Edwardian properties common in the area.
Unauthorised Work and Missing Building Regulations
Extensions, loft conversions, and garage conversions all sound great in theory, but not if the work was done without planning permission or building regulations approval. A survey can flag when something looks like it was added without the proper sign-off, which matters more than people realise.
Without documentation, you could face problems remortgaging, selling, or even enforcement action from the local council. You can ask the seller to obtain retrospective approval or knock the cost of doing so off the price, but you can only do that if you know about it. RICS has a clear overview of why home surveys matter and what each level covers, which is worth reading before you decide which type to commission.
Summary
A decent survey costs a few hundred pounds. The issues it can uncover can cost tens of thousands. That is not a difficult sum to do.