Building Under Permitted Developments
Not all changes or improvements to your home need planning permission. There are many that you can carry out with implied consent, known as Permitted Development. It is well worth being aware of these rights and recent changes to the rules, if you want to make any significant home improvement. It could save you time and money. But be sure to do your research, otherwise you could find your project costing more.
What is Permitted Development?
Permitted Development allows homeowners to undertake certain types of work without the need to apply for planning permission. There are many opportunities where permitted development right can bring significant benefits to anyone who wants to undertake a project to improve their existing home.
To determine whether your proposed project can be completed under Permitted Developments, we recommend checking with your local authority or getting confirmation from a qualified surveyor that your proposed works are classed as Permitted Development before you begin.
Do I Need Planning Permission When Building an Extension?

Not necessarily. In many cases you will be able to build an extension under Permitted Developments, but there are a few things to bear in mind. Any space added by previous owners since 1948 counts towards your permitted development allocation.
However, if you are planning a significant extension you’ll likely need planning permission. Speaking with your local authority early on and researching local planning polices to know what’s likely to get approved is a good idea.
If your house is located in a Designated Area, such as a National Park, Area of Outstanding Natural Beauty or Conservation Area then your Permitted Development rights may be restricted or removed. This is where rights have been removed in the interest of maintaining the character of the local area. This could also be the case if your property is listed.
Changes to Permitted Development Rights in 2019
The changes that took effect on 30 May 2019 now make permanent the decision that larger single-storey rear extensions of up to 8m (6m for semi or terrace) are permissible under Class A — but do require prior notification.
We believe this decision was made to encourage homeowners to invest in their property to provide relief to the current house shortage in the UK.
Key Permitted Development Rules for Extensions
- You can extend a detached dwelling by 8m to the rear if it’s single storey or 3m if it’s double
- Semi-detached and terraced homes can be extended up to 6m to the rear of the property if single storey
- There are height restrictions but they boil down to a single storey extension not being higher than 4m in height to the ridge and the eaves, and ridge heights of any extension not being higher than the existing property
- Two storey extensions must not be closer than 7m to the rear boundary
- It must be built in the same or similar material to the existing dwelling
- Extensions must not go forward of the building line of the original dwelling
- Side extensions must be single storey, maximum height of 4m and a width no more than half of the original building
- In Designated Areas side extensions require planning permission and all rear extensions must be single storey
- An extension must not result in more than half the garden being covered
- You can only do it once and the original building is either as it was on 1st July 1948 or when it was built. In Northern Ireland it is as it was built or as it was on 1st October 1973
Do you think extending your home is right for you? Whether it fall under Permitted Development or not, we are here to help. With a wealth of industry experience and knowledge, our team have the resources and contacts to make your vision a reality.
Give us a call today or 0117 978 3568 or email Enquiries@jhgroup-sw.com