Home renovating: do I need planning permission?

FEATURED IN DON'T MOVE, IMPROVE! 2020

Dormore by con | form architects used a mix of permitted development and full planning permission © Stale Eriksen

When starting out on your own home improvement project it can be hard to know what you need permission for, or if you need it at all. This article by by Resi & The Hopps Partnership demystifies permitted development rights to show you which kind of projects will fall within these agreements. Permitted development rights are a type of general planning permission granted by Parliament. If your plans fall within certain restrictions, this allows you to bypass submitting a planning application. Permitted development only applies to houses and outhouses (never flats or maisonettes), and there may also be exceptions if you live in a listed building or in a conservation area (‘Article 4’ direction). If you’ve had building work done in the past, you may also have used up some or all of your permitted development rights already. Like planning permission, permitted development is regulated through your local planning authority. You should always speak to a qualified architect or designer to make sure your plans are compliant before you start building, and consider applying for a lawful development certificate. You can use the following checklists to get a rough idea of whether or not your plans will fall within your permitted development rights.

You’re usually within permitted development rights if your single storey extension or conservatory...

Sits to the side (as long as this will not face a highway) or rear of the house (not the front)
Must not extend beyond the rear wall of the existing house by 3m if an attached house or 4m if detached
Uses similar building materials to the existing house
Takes up less than 50 per cent of the size of the land around the original house (‘original’ being the latest of when the property was built or if it was built before 1948, then as it stood on 1st July 1948)
If a side extension is less than 50 per cent of the width of the original house
Is less than 4m in height (or less than 3m if within 2m of a property boundary)
Has eaves and a ridge that are no taller than the existing house

You’re usually within permitted development rights if your loft conversion...

Adds less than 40m³ to a terraced house, or 50m³ to a detached or semi-detached house
Uses similar building materials to the existing house
Sits lower or equal to the highest existing part of the roof
A dormer wall that is set back at least 20cm from the existing wall face
Has windows that are non-opening if less than 1.7m from the floor level
Has side windows that are obscured/frosted

You’re usually within permitted development rights if your porch...

Takes up a total ground area less than 3 sqm
Has a highest point less than 3m
Doesn’t sit within 2m of a property boundary that leads to a road

What building work doesn’t fall under permitted development?

Balconies
Verandas
Raised platforms
Two storey side extensions within 7m of a rear boundary
Extensions with eaves higher than 3m (within 2m of a boundary)
Extensions exceeding 50 per cent of the original land around the original house
Eaves and a ridge of a loft higher than the height of the original house
Extensions over 4m tall or exceeding 50 per cent of the width of the original house
Extensions at the front of the house
Side extensions on designated land
Unobscured side windows above ground floor
Loft windows that can open when positioned less than 1.7m from the floor

What is a lawful development certificate?

If the legislation for permitted development on your project aren’t clear cut, or it has been conditionally withdrawn in your area, you should definitely apply for a lawful development certificate or may even need to submit a planning application. However, we recommend it for everyone using their permitted development rights. The process ensures that your building work (past, present or future) is compliant, and will protect you when you come to sell your property. The application process is similar to a planning application. You’ll need to provide:
An application form
Evidence verifying the information within the application.
This would include architectural plans and elevations
A site location plan
A fee

How can an architect help?

Whatever you’re hoping to build, your architect is likely to be able to make a few small changes that shift your plans within permitted development rights. Even though you can build without applying for a lawful development certificate, it can be extremely risky. On the off-chance that your plans aren’t actually compliant with permitted development, you may have to remove your extension at your own expense or proceed with a lengthy and expensive legal battle over who is to blame.

Don't Move, Improve! 2021

Look out for this year's shortlisted and featured projects announcement on 24 March. As part of it of this year's programme, expect more events including regular advice sessions with architects, engineers, and designers along with a 2021 magazine brimming with house improvement inspiration and an exhibition.