• Lisa Gardener

What You Need To Know About Building Regulations Before Extending


Building regulations are minimum requirements that apply to almost all new building work, including alterations to existing houses. There to control health, hygiene, safety, welfare, convenience, energy efficiency and sustainability, they are a legal obligation when carrying out building work, and failure to meet them is a criminal offence. Ensuring construction complies with the Building Regs is essential from the outset to ensure costly mistakes don't occur further down the line. Also, if you undertake work without getting it approved, it is likely to make selling the property difficult.


The Regs cover all aspects of construction, including foundations and underpinning, the stability of the building, damp-proofing, insulation, ventilation, heating, fire protection and means of escape. Repairs are not generally covered, provided they are minor or if you're replacing like for like, so if you're updating small areas of brickwork, re-pointing, plastering or rendering, or replacing less than half a roof, you can proceed without approval.



Where repairs involve removing some or all of a load bearing element, rewiring, extending or altering drainage or a heating system, replacing windows, work to any combustion appliances or substantial removal of roof covering or large expanses or wall finishes, then regulations will apply. However, if you're adding a porch, carport, garden outbuilding or small conservatory, approval is unlikely to be required.


The next step is to decide the type of application you need. There are two options: a Full Plans application or a Building Notice Application. The latter tends to be intended for minor works, while Full Plans is for substantial redesigns. Both need to be submitted to your local authority or building control body before you start work, and you'll need to pay the appropriate fee - the standard charges of which will be available from your local authority.


You're likely to need a structural engineer, too, to provide calculations for foundations, roof design and any structural alterations, and use an architect to produce detailed drawings.


When the design is ready, get in touch with a certified building control body, which include approved inspectors in the private sector, as well as your local authority's office. After you've submitted your application, including a written submission of your intention to start work, you can legally begin construction after two working days. If you have made a Full Plans submission, bear in mind that the local authority will not yet have had an opportunity to review drawings or advise on them, but you can expect a response within two weeks to confirm receipt. So if possible, wait for the verdict, just to be sure that no serious changes are required. Once approval is confirmed, it will remain valid for three years after the date of submission and, once work has started, there is no time limit for completion.



If you decide to make slight alterations to the design after work has started, this can usually be done as a minor adjustment, but confirm with the Building Regulations inspector before proceeding. There will be key stages during construction that require inspection, including during excavations for foundations, damp-proof course installation, drainage testing and construction of floor joists and roof timbers. You can request an inspections by phone, email or in writing, but you must give sufficient notice to allow a visit to be scheduled. Once the build is completed, a final inspection will take place and you'll receive an approval certificate or letter confirming compliance.