Building Regulations Guide for Extensions and Lofts

For many domestic projects, a local authority full plans application allows the proposed technical information to be assessed before construction. An initial notice route through a registered building control approver may also be available for eligible work.

A building notice is a more limited route for appropriate smaller works and does not produce the same up-front formal plans approval. Restrictions apply, including circumstances involving fire authority consultation and certain drainage situations. Confirm eligibility with the building control body; do not choose it simply to avoid producing design information.

Bring together architectural details, structural calculations, insulation, ventilation, drainage, glazing and fire precautions. A planning drawing set normally lacks the construction detail needed to demonstrate all of these matters.

Use the applicable editions of the Approved Documents and check amendments and transitional arrangements. They provide guidance on meeting requirements, not a universal design template that can be copied without assessing the building.

Agree the required notifications and inspections with the building control body before starting. Depending on the project these may include excavations and foundations, drainage, damp-proofing, structure, insulation and fire protection before concealment, and completion.

Do not concrete over an excavation, close a ceiling or board over steelwork before the required inspection or agreed evidence has been obtained. The contractor should know who books inspections and how missed visits will be resolved.

The client, designers and contractors have duties around competence and compliance. Identify the principal designer and principal contractor appointments where required, and distinguish building-regulations duties from the separate CDM health-and-safety roles.

Building control inspection is not continuous site supervision and does not replace design coordination, competent construction or the client's contractual administration arrangements.

Retain the completion documentation together with final drawings, calculations and relevant test and installation certificates. Electrical, heating, ventilation and other systems can require their own evidence.

Changes during construction need coordinated review. A completion certificate does not retrospectively grant planning permission, settle party wall matters or guarantee every element of workmanship.