What to Actually Check Before Buying a House

Everyone tells you the obvious stuff. Get a mortgage. Find a solicitor. Book a survey (and know the difference between a property report and a RICS survey). Great. Thanks. What nobody tells you is the list of things that will keep you awake at 3am six months after you’ve moved in, wondering why you didn’t check them before you signed.

This is that list. The non-obvious stuff. The things that don’t appear on the estate agent’s listing but absolutely will affect your life, your insurance premiums, and your resale value.

Flood risk (both kinds)

Most people, if they check flood risk at all, look at river and sea flooding. Fair enough — that’s the dramatic one. But surface water flooding is the one that actually affects more properties in England, and it’s the one most buyers forget about entirely.

Surface water flooding happens when heavy rain overwhelms drainage systems and water pools on the surface. It can affect properties nowhere near a river. The Environment Agency publishes data on both types, but they’re separate datasets with separate risk categories, and most people only check one.

Here’s why it matters beyond the obvious: insurance. If your property is in a medium or high flood risk area, your home insurance premiums can be significantly higher. Some insurers won’t cover you at all. Flood Re (the government reinsurance scheme) helps, but it’s not available for all properties. Check the flood risk before you fall in love with the kitchen.

Subsidence and ground stability

If you’re buying in London, the South East, or anywhere with clay soils, subsidence should be on your radar. Clay shrinks when it dries out and expands when it gets wet, which causes the ground to move, which causes foundations to crack. The British Geological Survey publishes shrink-swell data that shows which areas are most at risk.

Also look at the trees. Large trees near the foundations of a property can accelerate subsidence by drawing moisture out of the soil. That beautiful oak in the front garden might be slowly pulling the house apart. Your surveyor should flag this, but it helps to know before you get that far.

Lease length (if leasehold)

This is the one that catches people out more than almost anything else. The lease length matters enormously.

Under 80 years: extending the lease becomes significantly more expensive because of something called “marriage value” — essentially, the freeholder gets a share of the increase in value that the extension creates. The cost can run to tens of thousands of pounds. Under 70 years: some mortgage lenders will refuse to lend against it entirely, which means your pool of potential future buyers shrinks dramatically.

Always check the remaining lease length. If it’s below 90 years, factor the cost of extension into your offer. If it’s below 80, get a specialist leasehold valuation before you commit.

Service charges and ground rent

The leasehold trap, continued. Service charges cover the maintenance of communal areas, building insurance, and management fees. They vary wildly — I’ve seen £1,200 a year for a small flat and £6,000 a year for a large one in a managed development. Ask for the last three years of service charge accounts. Look at whether charges have been increasing and by how much. Check if there are any major works planned (roof replacement, cladding remediation, lift refurbishment) that could trigger a large one-off bill.

Ground rent is a separate payment to the freeholder. Some leases have ground rents that double every 10 or 25 years, which can make the property unmortgageable. The Leasehold Reform (Ground Rent) Act 2022 set new ground rents to zero for most new leases, but older leases are not affected. Check yours.

Planning applications nearby

That lovely unobstructed view from the bedroom window? Check the council’s planning portal. There might be a six-storey apartment block approved for the car park next door. There might be a new school, a waste facility, or a major road widening in the pipeline. Planning applications are public information and they can fundamentally change the character of an area.

Check both approved and pending applications. Approved ones are definitely happening. Pending ones might. Either way, you want to know before you buy, not after.

The neighbours

This is the most old-fashioned piece of advice on this list, and also probably the most useful. Knock on the neighbours’ doors. Introduce yourself. Say you’re thinking of buying the property next door and ask if there’s anything you should know about the area.

People will tell you everything. They’ll tell you about the parking, the noise, the neighbours on the other side, the flooding that happened three years ago, the development plans, the local Facebook group drama. You will learn more from a ten-minute chat with a neighbour than from hours of online research. Seriously. Do this. It’s one way to fill the information gap that estate agents won’t fill.

Phone signal and broadband

The listing might say “great broadband available” but that tells you nothing. Check the actual available speeds using Ofcom’s postcode checker. Is full fibre available, or are you stuck on copper ADSL getting 8 Mbps? If you work from home — and a lot of people do now — this is not a nice-to-have, it is essential.

Phone signal is even easier to forget. Check all the major networks for the specific address. Some properties, particularly in dips or behind hills, have appalling mobile reception. You will not notice this during a 15-minute viewing. You will notice it every single day when you live there.

Visit at night

This is the one that everyone says and almost nobody does. Visit the street at 10pm on a Friday night. How does it feel? Is it well-lit? Is there noise from a pub, a takeaway, or a main road that you didn’t notice during the daytime viewing? Are there groups of people hanging around? Is the parking situation different at night when everyone is home?

A property can feel completely different after dark. Your viewing at 2pm on a Tuesday tells you almost nothing about what the area is actually like to live in.

Water pressure

Run the taps during your viewing. Run the shower. Flush the toilet while the shower is running. If the water pressure drops to a trickle, that is something you will deal with every single morning for as long as you live there. Low water pressure is fixable, but it’s not cheap and it’s not fun. Better to know upfront.

Parking

Does the property come with a parking space? If not, is there a residents’ parking scheme? How much does a permit cost? How competitive is it? Some London boroughs charge over £200 a year for a permit, and even then there’s no guarantee you’ll find a space near your house. Visit the street at 8pm when everyone is home and see how many spaces are available. That’s the reality you’ll be living with.

Crime stats

Police UK publishes street-level crime data monthly. Check the actual data for the specific neighbourhood, not just the borough average. Crime varies enormously street by street. A borough might have average crime rates overall but a specific pocket with high burglary or antisocial behaviour. Look at the data by category — burglary and vehicle crime affect homeowners very differently from antisocial behaviour — and check trends over the last 12 months, not just a single snapshot.

Schools (even if you don’t have kids)

School catchment areas affect property prices. A lot. Being in the catchment of an “Outstanding” primary school can add tens of thousands of pounds to a property’s value. Even if you have no intention of having children, your future buyer might, and that will affect how easily — and for how much — you can sell.

Check the Ofsted ratings of nearby schools. Check whether you’d actually be in catchment (some oversubscribed schools have catchment radii measured in hundreds of metres). And check whether there are any new schools planned that might change the picture.

What a Viven report covers (and what you still need to do yourself)

A Viven report covers most of the data checks on this list automatically: flood risk (both river and surface water), subsidence risk, crime statistics, school ratings and distances, broadband speeds, transport links, planning applications, EPC data, comparable sales, and more. It pulls from 15+ government sources and delivers the results in under 30 seconds for £14.99.

The things you still need to do in person: visit at night, check the water pressure, talk to the neighbours, and test the parking situation. No report can replace physically being there. But a report can save you hours of online research and flag problems before you waste a Saturday on a viewing.