Thames Water build-over CCTV surveys for London extensions and basements. You get a pre-work condition survey and a post-build check. We produce both to the standard Thames Water needs for structures built over or near public sewers.
You need a Thames Water build-over agreement when you build within 3 metres of a public sewer. This covers extensions, outbuildings, basements and driveways. The agreement protects the sewer from damage. It also lets Thames Water reach the pipe for repairs without pulling down your new structure.
Thames Water asks for a pre-build CCTV survey that shows the sewer's current condition. It also asks for structural drawings from your architect. These show how the new structure sits against the sewer run. We write our survey report with WRCm defect grades and a pipe condition check, because their technical team looks for these.
Thames Water usually asks for a post-build CCTV survey as well. It confirms that building work has not harmed the sewer. We work with architects and structural engineers throughout, and we supply both reports under one agreed cost. Complete reports help you avoid delays from resubmitting.
We also advise whether your project needs a full build-over agreement or the lighter build-near process. Build-near applies to structures between 3 and 5 metres from the sewer. It carries a lower reporting load.
Start early with any build near a sewer. Since approval takes time, a late application can hold up your project. While your architect finalises drawings, we can book the pre-build survey. This keeps the whole job on schedule.
Prices vary because every job differs. Build-over surveys depend on scope. A pre-build survey and report cost less than a full package with both surveys and both reports. We produce every report to the Thames Water submission standard. Request a quote online.
Thames Water asks for a pre-build CCTV report that shows the condition of the public sewer, graded to WRCm standards. They also want structural drawings from your architect that show how the structure sits against the sewer. A method statement must explain how the sewer will stay protected during building. We write the CCTV report to the standard they accept.
No. A build-over agreement applies when the structure is within 3 metres of a public sewer, or directly above it. A build-near agreement applies between 3 and 5 metres. Build-near has lighter reporting. We can advise which one fits your project, using your architect's drawings and the sewer position.
The review takes some weeks. A complete application with a well-formatted CCTV report gives you the best chance of avoiding delay. Incomplete applications are the usual cause of rejection and resubmission.
No. Wait until Thames Water gives written approval. Starting early can cause serious problems, including a demand to alter the structure at your own cost. We always advise getting the agreement before any groundworks begin.
While you plan the work, read our guide Thunderstorm Prep: 5 London Drain Checks Before Heavy Rain. It covers what to check before you ask for a quote.