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% 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% 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
To name just a few of the requirements!
However, not all homes qualify for the scheme, even if they follow the rules above. Permitted development rights do not cover…
- Listed buildings
- Homes within conservation areas
If you wish to extend any of these properties, you’ll need to apply for planning permission.
Lawful development certificate
Even if you plan on avoiding planning by using your permitted development rights, you’ll still want to document your decision.
Many future buyers will be wary of purchasing an extended property if there’s no proof the build was legal. This is because, if your extension gets found to be a faction too big, your loft design a little outside the guidelines, you can face not only some hefty fines but can even be made to demolish the work. Naturally, these penalties won’t be something another homeowner will want to risk.
Lawful development certificates can be obtained in retrospect. However, you’ll need to pay twice the application fee. And as we said, if getting a certificate post-construction, and your build falls outside of your permitted development rights, you might face some pretty scary consequences.
What’s more, planning policies change. What might be included in permitted development today, might not be in 15 years. This is why you need proof that, at the time, what you did was considered legal.
Learn more about applying for a lawful development certificate.
Applying for planning permission
Working with an architect, you’ll first need to prepare your planning package. This will include…
- Your application
- Existing drawings of your property
- Proposed designs of your extension
- A site location plan
- Plus a fee
Once this is submitted, you’ll need to wait for the application to be validated and assigned a planning officer. This can take anywhere between 7-14 days or even (in extreme cases) up to 5 weeks.
With a planning officer assigned to your project, they’ll then start their assessment. This too is a lengthy process and, at minimum, reaching a decision will take at least 8 weeks.
To give your project the best chance of success, we recommend having an architect act as your planning agent during this process. Not only will they make sure your package is the best it can be, but they’ll also liaise with your local authority throughout their decision making - even making slight changes to your design, should they be needed to get it across the line.
Learn more about planning.
Want to make sure you nail planning the first time around? Or perhaps you’re unsure whether permitted development applies to your home? Whatever your concerns, Resi provides free consultations to make sure you kick off your project with confidence. Book in your free advice call here.