Do You Need a Drain Survey When Buying a House?

Short answer: yes, in most cases. A standard building or homebuyer survey does not usually look inside the drains. Yet a damaged drain can cost thousands to put right, and you can’t see it on a walk-round.

A CCTV drain survey before you exchange contracts, or in Scotland before the missives are concluded, is a cheap guard against a very costly surprise. Here’s how to decide whether you need one, and what it gives you.

Why a normal house survey misses the drains

A RICS building survey or homebuyer report looks at the parts of the house a surveyor can see and reach. The drains are underground, so they fall outside almost every standard survey. That leaves a blind spot where some of the costliest faults hide: cracked or collapsed pipes, roots, and poor connections.

So you can pass every other check and still take on a four-figure drain bill when you move in.

When a drain survey is well worth it

Book a homebuyer drain survey if any of these apply:

• The property is more than about 30 years old. Older clay pipes are more likely to crack or let roots in.
• There are mature trees near the house or boundary. Roots find their way into drains and can split them.
• The garden slopes, or there’s an extension. Building work can disturb drains or cover them over.
• You noticed slow drains, smells or damp during viewings.
• It’s a new-build. Site drains can still have faults or debris, and a survey gives you evidence to raise with the developer.

Local housing matters too. The city pages describe what is common where you are buying, from inter-war and post-war homes in Birmingham to Victorian suburbs in Nottingham and mixed post-war streets in Coventry. You can find your own city in the list of cities covered.

Even where none of these apply, the cost is small next to the peace of mind.

What a homebuyer drain survey covers

The survey sends a camera through the drains and records their true state. Ask for:

• Footage of each pipe run.
• A report, ideally WRc/MSCC-coded, listing each defect, where it is and how serious it is. See drain survey reports.
• Plain-English advice and, where useful, a rough idea of repair costs.

Solicitors, lenders and insurers know the WRc/MSCC format. So a coded report is one you can act on straight away, once you know how to read a drain survey report.

The real value: room to negotiate

If the survey finds a defect, you have two strong options before you commit. You can ask the seller to fix it, or you can renegotiate the price to cover the repair.

The survey takes place before exchange, so the problem doesn’t simply pass to you. If it finds a collapse, you can still go ahead with buying a house with a collapsed drain, but agree who pays for the repair first. That one point is why a homebuyer drain survey can more than pay for itself.

Who pays for it?

The buyer normally arranges and pays for the drain survey, just as for the building survey. Why a homebuyer drain survey is worth it covers the timing in more detail. It is a small cost up front that protects a very large purchase. For a sense of the figures, see the CCTV drain survey cost guide.

The bottom line

A house survey tells you about the building. A drain survey tells you about the one system that can quietly cost you thousands, and a standard survey usually leaves it out. Book it before you exchange, while the findings still give you room to negotiate.

Send us the property’s postcode and we’ll pass your request on straight away. Tell us your exchange date, and ask for a report you can give your solicitor.