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By: grace

How Much Can I Extend My House Without Planning Permission?

planning permission extension

do i need planning permission for an extension?

The answer is no.
You do not need planning permission for all extensions depending on the size, without planning permission you can build up to six metres or eight if your house is detached. However there are other rules we have laid out below:

  • No more than half of the land around the house can be covered by other buildings
  • No extension can be forward elevation or side elevation in front of an highway
  • No extension can be higher than the highest part of your roof
  • Single storey extensions cannot extend beyond the rear wall of the original building by more than 8 metres.
  • Max height of a single-storey extension is four metres
  • Extensions more than one storey cannot be extended beyond the rear wall by more than 3 metres of the house
  • Two storey extensions cannot be closer than seven metres to the houses rear boundary
  • You cannot have balconies, verandas or a raised platform

extension without planning permission

How much can i extend my house without planning?

Ask yourself these questions before building an extension without planning permission:
1. Is your property a house or flat?
Flats and other types of buildings do not have permitted development rights. You won’t be able to build an extension with full planning permission if it is not a house. Also be aware if your house has already been converted in the past it may not be eligible for permitted development rights.
2. Have you extended the house since 1948?
If you have had a previous extension this will make your home not eligible for the permitted development allowance.
3. Is your property a listed building?
Protected areas around your home can stop you having an extension, check if you are near any listed buildings or areas as your permitted development rights will be removed.
This means you cannot do the following:

  • build above one storey
  • build a side extension
  • cladding on the exterior


The guide below to permitted development rules for extensions can help you understand if you will be allowed to build an extension on your home:
Front Extension Permitted Development Rules

You cannot have a front extension without planning permission but you can still apply.
Side Extensions Permitted Development Rules
1. Cannot be more than half the width of the house
2. You cannot extend further than three metres of the original house
3. Your side extension must not front onto a road.
4. You cannot have three metres out from the original house
Single Storey Rear Extensions Permitted Development Rules
Under the new rules you can extend to eight metres for detached homes or six for all other types of homes. For extensions that are over four metres you will need to give notification to your neighbours and with objections you may not be able to build an extension this large.
Double Storey Rear Extensions Permitted Development Rules
Double Storey extensions can only be up to three metres from the original house
Cannot be closer than seven metres to the rear of the home
The shape of the roof must match the existing home
The side facing windows must be above 1.7 metres above the floor


If you are looking for advice about planning permissions and extensions it’s best to consult a professional, here at Create Room we are fully qualified to offer you advice on planning permissions and extensions on any projects you may have questions on.
It’s always best to consult professional advice before building a house extension incase you do break any of the above rules.
Contact us now for free advice on your home extension project.