Build Over Agreements
Build Over Agreements – Essential for Sewer-Safe Projects
When extending your home, particularly with rear or side extensions, you may come across shared or public sewers running beneath your property. In such cases, you are legally required to obtain a Build Over Agreement from your local water authority (e.g., Thames Water in London).
At OAS, we guide you through this complex process and ensure your project is legally compliant and structurally safe.
Why Do You Need a Build Over Agreement?
Public sewers are owned and maintained by the water authority. If you build over them without approval, it may:
Cause damage to the sewer line
Increase the risk of flooding or blockages
Lead to refusal of building completion certificates
Even force demolition of your extension if built illegally
Our Build Over Agreement Services
Site Survey & Assessment – Identifying whether your project is affected by public sewers.
Technical Drawings & Calculations – Providing accurate layouts, drainage plans, and structural details.
Application Submission – Preparing and submitting all documents to Thames Water (or relevant authority).
Liaison with Authorities – Communicating with officials to secure fast approval.
Compliance Guarantee – Ensuring your project remains safe, legal, and protected.
Benefits of Using OAS for Build Over Agreements
✔ Avoids project delays and costly legal issues
✔ Provides full technical and engineering support
✔ Protects your investment by ensuring compliance
✔ Peace of mind that your property and sewer system are safe