UK Planning Permission Guides

Usually not on a rear or side roof slope, provided the added volume stays within your allowance (40m³ terraced, 50m³ semi-detached or detached), the dormer is set back at least 20cm from the original eaves and it does not go above the highest part of the existing roof. A dormer on the principal elevation facing a highway always needs permission. Previous extensions count against the same volume allowance, so an already-extended house often has less headroom than owners expect.

A householder application in England has a statutory determination period of 8 weeks from validation. Note that validation is not submission — if the council asks for more information the clock has not started. Allow 10–12 weeks door to door, and longer if you are in a conservation area or the case officer requests amendments.

Planning controls what you can build — size, siting, appearance and impact on neighbours. Building regulations control how it is built — structure, insulation, fire safety, drainage and electrics. They are separate consents from different teams. Permitted Development removes the planning application; it never removes the need for building-control approval and a completion certificate.

Yes. Objections are considered, but the council can only refuse on planning grounds — overlooking, loss of light, scale, design, parking. Objections about loss of view, disruption during the works, or the effect on property value carry no planning weight. Separately, if you are building on or near a shared boundary the Party Wall etc. Act 1996 may apply, and that is a legal process independent of planning.

The council can serve an enforcement notice requiring you to alter or remove the work. In England there is now a 10-year immunity period for most unauthorised building work, but relying on that is risky and it will surface on any sale. If you have already built, a retrospective application or a Lawful Development Certificate is the route to regularise it.