Do I Need a Drain Survey For an Extension?

Building an extension or modifying your home can be an extremely long, stressful task requiring a lot of planning, budgeting, and managing. The best part of building an extension is that that part of your home becomes uniquely yours, allowing you to custom build your space. However, with construction material shortages, lack of HGV drivers, and the rise in the cost of building, it is vital all of your paperwork is ready to go before applying for permission. This is where a drain survey comes in handy. Drain surveys are almost always forgotten when purchasing a new home or applying for a home extension. When applying for an extension, you will most likely need a pre-build or pre-conditional survey which clarifies drain ownership. If your extension builds over a drain, this makes logistics a little more complicated as your drainage system may need to be updated. A drain survey makes the application for an extension much smoother, and also helps you find and understand any issues which could become more expensive problems in the future.

What is a Drain Survey?

It is highly recommended that prospective home buyers purchase a drain inspection before committing to a new home. Whilst a home receives a general survey, this is not in-depth enough for any drainage problems to be discovered. A surveyor will evaluate a home’s roofing, insulation quality, the condition of the doors and windows, damp proofing, and so on. Surveyors will often recommend homeowners also purchase a drain survey as it provides a much more detailed understanding of the home. A drain survey involves a high-resolution camera being fed through a home’s drains, gaining access from an exposed pipe or manhole. One engineer operates the camera and the other engineer, who stays above ground, maps out your drain system, taking note of any issues. A drain inspector will be able to see:

  • Where your drains connect and if this leads to sewage lines
  • What material your pipes are made from, their condition and size
  • If there are worrying build-ups in your pipes of debris and grease which could cause a blockage or are at risk of becoming a bigger problem
  • If any drains have split, collapsed, or damaged
  • If there is a build-up of scale what could lead to corrosion

A drain survey report can be very quickly created on a same-day basis, meaning you never have to wait on your results. This can be very handy if you are applying for an extension and need a quick turnaround on documents. In a drain inspection report, professionals will give a detailed outline of your drainage systems’ health, outlining every issue and its location. A drain inspection will also outline how close your home sits in relation to public drainage systems. If your extension will be built over areas closer than 3 metres to a public system, you will need to ensure the local water authority also approves the extension.

How do I Get a Drain Survey?

If you are thinking of adding an extension to a property, Aspect’s professional drainage engineers provide a comprehensive drain survey, giving you confidence that your building project will meet industry standards. A drainage system for a small home can take only one hour, if your home is slightly larger it may be up to three hours. As a general rule, engineers work at ‘one hour per manhole’, however, no two surveys are the same. In the future when you possibly sell your home, or if you plan to further modify your home, a drain survey adds value in showing you have a fully functioning system the new homeowner can rely on.