Adding an Extension as Permitted Development

What Are Permitted Development Extensions?

Permitted development extensions do not require planning permission from the local authority as they utilise Permitted Development Legislation which grants building owners some specific entitlements to develop their buildings. Permitted Development Rights are applicable to both single-storey and double-storey extensions, however they have to meet certain conditions depending on the building type (e.g. detached, semi-detached, terraced, listed building) and their location (e.g. Area of Outstanding Natural Beauty, Conservation Area etc). One significant advantage of Permitted Development extensions is that they can be built without your neighbours being consulted, unlike Planning Permission applications.

A couple of examples of Permitted Development rules affecting extensions are:

  • Extension/s AND ancillary buildings (including sheds and other types of outbuildings) cannot cover more than half the land surrounding the original house.
  • Extensions cannot go beyond the highest part of the roof. Building above the original roof height will require Planning Permission.

How Big Can a Permitted Development Extension be?

  • You can build a single storey extension 8m from the rear wall for a detached house, unless you live on ‘Article 2(3) Land’ (e.g. Conservation Area etc) in which case it is 4m.
  • For a single storey extension on a semi-detached or terraced house you can build backwards 6m from the rear wall, or 3m on Article 2(3) Land
  • The allowances in 1&2 above require at least 7m space between the extension and the rear boundary of the property (usually the garden back fence)

Permitted Development rules can become quite complex in regards the width of a Permitted Development extension, based on whether you have/will have a side extension and whether the house rear wall consists of 2 or more rear walls projecting to different measurements creating a ‘stepped’ rear wall. We recommend getting the advice of an architectural designer who will be able to look at the attributes of your property and advise on what you can do under Permitted Development Rights.

Do I Have to Apply to The Council For Permitted Development?

In short ‘no’ you don’t have to. Permitted Development is your entitlement to build an extension, as long as it qualifies for and is built according to Permitted Development rules. It is advisable to check with the Council that your property has Permitted Development Rights, as sometimes they are removed. For example, Planning Permission may have been granted some time ago for a side extension on a house but Permitted Development Rights were withdrawn as a planning condition when the application was granted. Once you know that your property qualifies for Permitted Development, you can submit drawings to your Council with a Lawful Development Application which provides proof for a mortgage lender, future home buyer or planning officer that your extension complies with Permitted Development Regulations.

What Happens if my Extension Breaks Permitted Development Rules?

The outcome of building an extension that doesn’t qualify as a Permitted Development, is that the Council can issue an enforcement notice which would require the owner to rectify the issue or apply for Planning Permission.

What Should I do Before Building my Permitted Development Extension?

We recommend using a specialist architectural designer to help you design your extension and ensure it meets Permitted Development Regulations. My Home Plans UK is a dynamic business providing architectural design and planning services. We design Permitted Development extensions and loft conversions for homeowners across England and Wales and we submit and manage Lawful Development Applications and Planning Applications for our clients.

How Much do Extension Drawings Cost?

Our house extension drawings cost just £495 and include unlimited changes for this fixed fee.