Guidelines for building close to or over sewers and drains

15 May Guidelines for building close to or over sewers and drains

A number of regulations are in place to formally protect public sewers and drains that could be impacted when construction works, renovations or extensions are planned over or close to them. These are discussed below:

What regulations are in place for building close to or over sewers and drains?

Anybody planning to build within three metres of public sewers or lateral drains needs to obtain Building Regs H4 approvals, which includes approval from the water authority prior to commencement of any work.

It’s important for any builder to identify locations of any drains that will be impacted by construction works, even if they are not actually public sewers or shared drains.

Identifying the depth of the drain is also critical as shallow drains may not have the ability to enable successful drainage from the new build project, while deeper drains could need deeper foundations.

All these factors need consideration at the planning stage of any new build, and Building Regulations approvals should always be sought in advance. Working collaboratively with the appropriate water authority can help resolve any issues or problems that could arise in future.

Possible restrictions and guidelines for building close to sewers and drains

Working in collaboration with water companies when you need to build close to or over drains and sewers is the best way forward. If there are sewer pipes on the proposed building land no work should be commenced prior to water authority approvals and this is the case even when construction is exempt from building requirements.

Additional restrictions are in place for sewers with a depth of more than three metres or where additional piling is required. Very often water authorities place requirements for underpinning, piling or mini pile construction to be carried out if there has been extensive ground movement prior to works starting or if there is any possibility of further movement or poor soil impacting on the building works. Subsidence of the existing structure can also have a real impact on sewers and drains in the vicinity.

BSB Concrete Services provide underpinning and piling in London and the surrounding area. We specialise in offering all the support needed to ensure building works will not impact on nearby sewers and drains. Get in touch for more details.