PPCo Guide: How to build a home extension #3 - planning permission
Updated for 2021/22
This article is the third in our new PPCo Guide: How to build a home extension - a series which will take you step by step through the process of designing, planning and building your extension.
In the first edition of this series we talked about the very initial stage of planning a home extension and then we moved on to the design stage.
Next up is planning permission - whether or not you need it, and what it entails.
What is planning permission?
The planning process involves asking your local authority for permission to do a certain piece of building work. Permission is either granted or refused based on a number of different factors.
Planning permission, however, is not always required and this is where permitted development rights come in.
Permitted Development (PD)
Everyone in England has the right to add to or improve their property under permitted development, as long as the work meets certain conditions.
By keeping a project within permitted development rights, this saves the homeowner the planning fee (£206 for a standard householder application) and 8-10 weeks in time - the typical period taken for a decision to be made by the council. And at the moment, due to the restrictions imposed by the Covid pandemic, planners are sometimes taking several months to issue their decisions. So it’s definitely something to consider during the design stage.
For home extensions, the following works fall under permitted development:
Single storey side extensions up-to half the width of the original house (the house as it stood originally, not including any existing additions, extensions, etc.), not exceeding four metres in height and in matching materials (to the existing property).
AND
Single-storey rear extensions not exceeding more than four metres in height and not extending beyond the rear wall of the original house by more than four metres (detached property) or more than three metres (semi-detached/terraced property), and in matching materials.
There are also permitted development rights for extensions of more than one storey but to apply, the design would need to be further than seven metres away from any boundary opposite the rear wall of the house. In our experience, it is very rare for this to be the case, so for the majority of double storey extensions, planning permission would be required. There are further conditions for extensions of more than one storey, details of which can be found here.
PD rights also state that only half the area of land around the original house can be covered by extensions or other buildings, so this needs to be kept in mind.
And if you want written proof from your local authority that your proposal does not require planning permission, you can apply for something called a ‘Lawful Development Certificate’.
If you’re not sure whether your planned home extension would come under permitted development, or you’d like to apply for a lawful development certificate, please contact our team.
Prior Approval
Something that can be a little confusing is the Notification for Prior Approval for a Proposed Larger Home Extension scheme, which allows homeowners to build larger single storey rear extensions (up to six metres on a terraced/semi-detached property and up to eight metres on a detached property) without planning permission.
It involves ‘notifying’ the local planning authority prior to carrying out the works. The council will then consult with the adjoining neighbours and while they may object, this does not mean the proposal cannot go ahead. It is up to the council to determine whether the proposal’s impact on the neighbours is acceptable or not.
Any limitations to do with permitted development will still apply with prior approval proposals.
When might you need planning permission?
Deciphering whether a proposed project comes under permitted development or not can be quite confusing - and frustrating when it turns you do indeed need permission.
For example, you might own a semi-detached red brick property and you might want to extend out the back. A small rear extension would likely fall under permitted development due to its size and location but as soon as you want to change it to a render, then you need permission from your local council.
You might even find that even though your proposed project technically falls under permitted development, your PD rights have been removed because you’re part of a new build development where certain limitations were imposed as part of the development’s original planning approval.
Below is a non-exhaustive list of some of the reasons why permission might be required:
Materials which don't match existing
Large footprint
Development at corner of property
Development in a Conservation Area
Development on a new build property
Why might planning permission be refused?
All planners and councils have different quirks and preferences but in general, the same standard planning rules apply.
Permission will likely be denied if:
Your build overshadows or overlooks a neighbour, causing a loss of light and/or privacy.
The proposed design is out of character with the existing property and the street scene.
Things like highway/road safety and impact on trees/roots are also taken into account.
A good place to begin is to research the local authority’s online database of planning applications to see what has been approved in the area and then take lead from those builds.
And if you employ an architect or designer, they will negotiate with planners on your behalf and you can rely on their knowledge and experience to get you the best possible outcome.
We would always advise that your top priority should be to speak to your neighbours and give them the heads up on what you’re planning - and make sure your designer is considering them at all stages. There is also something called the Party Wall Agreement, which is separate to planning permission. For any queries on this, please take a look here.
We have a post on our website which includes a link to a useful tool that makes it easy to check planning permission approval rates in your area, as well as a few more our top tips for getting your application approved. You can read it here.
Planning advice is up to date as of 15th December 2021. Further information can be found on the Planning Portal.
Coming up…
How to build a home extension #4: building control
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If this is the first article you’ve seen in this guide, why not check out the first instalment here and catch up!).
No matter what stage you’re at in your project, our team is here to help. If you’re based in the East Midlands and you’d like to book in with our Nottingham team for a free, no obligation design consultation, please give us a call on 0115 874 8570 - or hit the button below.
Our fixed fee packages include all the necessary plans and guidance for a planning application. Plus, we handle the submission and all communications for you. For an idea of prices, please use our online calculator.
If you’re not quite ready to get started, or you’re based elsewhere in the UK, please feel free to check out the rest of our Advice Centre - and connect with us on Instagram and Facebook for tips and inspiration.