Build Over Agreement Guide

A build-over (or build-near) agreement is consent from the water company to construct over or close to a public sewer or lateral. Without it, foundation and drainage works can be refused or delayed even if Building Control is otherwise content.

This consent-profile page explains what groundworks teams need from the agreement process. Detailed construction-drainage ownership also sits on build-over drains and sewers. Mainline builds to the consented design; we do not obtain the agreement on your behalf unless separately appointed for that coordination role.

review Bulk Earthworks in Reigate and Groundworks Contractors in Wandsworth.

When consent or agreement is required

When asset plans show a public sewer under or near the extension or new-build footprint; when CCTV reveals a sewer in the dig zone; or when the water company requests protection, diversion, or specific foundation bridging details.

What the consent process usually covers

Typical steps before dig: confirm sewer ownership and location, arrange CCTV if required, submit the build-over application with structural details, and wait for consent conditions.

Construction may then include protection slabs, bridging foundations, diversion, or carefully controlled excavation beside the pipe — exactly as the consent and engineer specify.

Private drains can still need careful workmanship; “build-over” language usually refers to public assets.

If this matches your project stage, send drawings and site details for a scoped quote — or call to talk through programme and access constraints.

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Triggers that start the process

Public sewer on asset plans near the footprint
Water company requesting build-over application
CCTV condition survey required
Protection or diversion detail on structural drawings
Building Control asking for sewer consent evidence

Evidence and submission checklist

Water company asset information
CCTV report if required
Structural build-over / protection drawings
Written consent / conditions on file
Inspection expectations during works

Typical consent pathway

Step 1: Identify the asset
What this step delivers: Public vs private and location clear.
Step 2: Survey and apply
What this step delivers: CCTV and application submitted.
Step 3: Receive consent conditions
What this step delivers: Buildable protection/diversion detail.
Step 4: Construct to consent
What this step delivers: Works and records completed.

Construction constraints after approval

Work only to consented drawings and conditions. Record as-built protection details for the property and water company file.

Programme risk if consent lags

Diversions, protection slabs, and programme waiting for consent dominate. Starting dig before consent is false economy. Cost pages for related drainage works sit under /groundworks-costs.

Frequently asked questions

Can I start foundations while the build-over is pending?

Not over or affecting the public sewer. Consent conditions can change foundation details — wait for approval.

Is a build-over the same as a connection agreement?

No. Build-over is about constructing near an existing public sewer. New connections are a separate consent process.

How This Issue Is Normally Diagnosed and Repaired

Follow the typical path from problem identification through to resolution:

We provide these services across the UK, including

London Richmond Chiswick Wimbledon Kingston Fulham Hammersmith Ealing

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Have build-over consent and drawings? Request a construction quote.

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