Home Improvement Permissions: What You Need and When

One of the most confusing aspects of home improvement is knowing which projects require formal permission and which do not. Getting this wrong can be costly — either in the form of enforcement action, or in difficulty selling your home later. This guide cuts through the confusion.

Many homeowners conflate planning permission and Building Regulations, but they are entirely separate systems. Planning permission is about whether you are allowed to build something in principle — it is concerned with appearance, impact on neighbours, and land use. Building Regulations are about how it is built — structural safety, fire safety, energy efficiency, and accessibility. You may need one, both, or neither, depending on the project.

Most minor home improvements fall under permitted development rights — meaning you can carry them out without applying for planning permission. This includes single-storey rear extensions within certain limits, loft conversions with no hip-to-gable changes or rear dormers on principal elevations, outbuildings within limits, and most internal alterations. These rights were revised in 2020 to be more generous in many respects.

Permitted development rights allow homeowners to improve their properties without the burden of a full planning application — but these rights have limits and conditions that are easily overlooked.

— Planning Portal, UK Government

Some projects always require full planning permission: building a new dwelling (even an annexe if it will be independent), two-storey side or rear extensions in most cases, adding a new storey to a house, changing the use of a building, and most changes to the exterior of a listed building. When in doubt, submit a pre-application enquiry to your local planning authority — it costs a small fee but gives you certainty.

If your property is in a Conservation Area, an Area of Outstanding Natural Beauty (AONB), a World Heritage Site, or a National Park, your permitted development rights are significantly reduced — particularly for extensions, cladding, and outbuildings. Article 4 Directions can also remove permitted development rights in specific areas for particular reasons. Check with your local authority if you are unsure.

Even where planning permission is not needed, Building Regulations approval usually is for anything that affects structure, drainage, heating systems, electrics in kitchens and bathrooms, or fire safety. Your builder or tradesperson should handle this — but always confirm upfront who is submitting the Building Regulations application and who will obtain the completion certificate.