In short
Before you exchange on a rural home off the mains, find out which drainage system it has. It may be a septic tank, a cesspit or a packaged treatment plant, and the rules differ for each. Ask where it discharges, and whether it meets the Environment Agency's General Binding Rules.
You should also ask for any service history and any test results, because they show how the owner has looked after the system. If you are not sure where to start, send a request online and we will pass it to a local engineer.
Why a homebuyer survey may miss the drains
A RICS Level 2 or Level 3 survey looks at the structure, roof and walls. It covers what the surveyor can see or test from the surface. The drains in the garden are often left out, because checking them needs specialist kit.
As a result, a buyer can inherit a system that leaks, blocks or breaks the rules. Many homes around Deddington and Shipston-on-Stour are off the mains. The gap in the survey therefore matters more here than it does for a town house.
The septic tank trap at sale
The General Binding Rules say a septic tank must not discharge straight into a ditch, stream or river. Since 1 January 2020, the owner of a tank that does so has to replace or upgrade it. Sellers must also tell buyers in writing about the system.
Conveyancing solicitors increasingly ask for proof that a system complies. However, that proof is often missing for older homes. A late surprise can delay completion or add an upgrade to your costs.
Our guide to the General Binding Rules in Oxfordshire explains what the rules require. It also shows why a missing record matters, although many sellers can find one.
A pre-exchange checklist
Work through a short list with the seller or their agent before you commit. The answers tell you what you are really buying.
- Ask what type of system the property has: septic tank, cesspit, treatment plant or soakaway.
- Ask for emptying and service records. A licensed waste carrier's paperwork shows how often the tank was emptied.
- Ask where the system discharges to, and for any permit or paperwork that goes with it.
- Book a CCTV drain survey to check the pipework itself.
The survey matters most on older homes, because clay or pitch fibre pipes may have worn. Our pre-purchase drain survey page shows what a visit involves. If repairs follow, our septic tank services cover repair and upgrade work.
What a CCTV survey shows
A survey feeds a waterproof camera through the pipes and records what it finds, which a visual check cannot do. It can show tree roots working into joints and cracked or displaced pipes. It also reveals pipes with too little fall, as well as silt and fat deposits that nobody can see from above.
Engineers usually grade defects with the WRc MSCC5 scheme. This rates faults from minor wear to severe failure. A buyer then sees what work the system may need, since a standard survey cannot show it. Our CCTV drain survey guide for home buyers gives more detail, and our piece on what a survey costs explains what affects the price.
Final checks before you exchange
Have the following in hand before you exchange contracts. First, a clear description of the system and where it discharges. Second, copies of any service logs, emptying records or permits. Third, the results of a CCTV survey, with any serious defects marked.
Finally, ask your solicitor to confirm that the system meets the General Binding Rules. If it does not, agree in writing who pays for the work. These steps protect you from a repair bill that appears only after completion.
Help near the villages
We cover the rural areas around Banbury, while our reach also extends just across the Warwickshire border. For a camera check, see our pages on drain surveys in Shipston-on-Stour and CCTV drain inspections in Southam. If a survey finds damage, read about drain repairs in Deddington and drain repair help in Shipston-on-Stour.
For the other services we cover, you can also look at our Deddington area page and our Shipston-on-Stour area page. Each lists the work we do there, although the septic pages cover those two areas best.
Related guides
Three guides help with the tank itself. For example, start with the differences between septic tanks, cesspits and treatment plants. Then read how often a septic tank needs emptying. If a pipe crosses your boundary, our guide to whose drain it is under Thames Water rules explains who clears it.
Frequently asked questions
Do I need a drain survey when buying a house?
If the property is off the mains, a drain survey is well worth arranging. A standard survey does not inspect the buried pipes or the tank. A CCTV survey fills that gap and can help you avoid repair costs after completion.
Can a septic tank stop a house sale?
A tank that breaks the General Binding Rules may need an upgrade or replacement. Solicitors often ask for proof of compliance, so a sale can stall until it is sorted. That is why it pays to check the system early.
How do I find out what drainage a property has?
Ask the seller or estate agent directly before you make an offer, since it is a fair question. If they cannot answer, that is useful information too. A site visit or CCTV survey can then establish the facts.
What is the difference between a septic tank survey and a drain survey?
A CCTV drain survey examines the pipework. A septic tank assessment looks at the tank or plant, its condition and where it discharges. For an off-mains home, it is worth having both, because one does not cover the other.
