Do you need planning permission for an oak frame extension? Building an extension can be a great way to get the additional living space you need without moving house. Whether or not you need to make a formal planning application for an oak frame extension will depend on a number of factors. Here we take a closer look at what needs formal planning permission and the key things you need to consider to ensure your project is a success.

Do I need planning permission for an extension?

Many extensions already have Planning Permission thanks to the General Permitted Development Order.  As a general guide, when building a more ambitious oak frame extension you will need planning permission if:

It’s above a certain size 

• Your extension including other buildings will cover more than half the area of land surrounding the original house;
• You are extending above the overall height of the original house;
• Your single storey extension is taller than four metres;
• Your extension is over 100m2. Extensions of this size may be liable for Community Infrastructure Levy (CIL) payments. However, if you’re going to live in the property for three years after completing the extension then you can claim for an exemption;
• Your single storey extension is to the side of the property and more than half the width of the original house;
• Your double storey extension extends beyond the rear wall of the original house by more than three metres;
• You plan on building a balcony or raised veranda;

You are extending near or towards specific things

• You are extending towards a road;
• You are extending more than six metres from the rear of a semi-detached house;
• You are extending more than eight metres from the rear of a detached house;
• You are extending a property that is situated on designated land or a Site of Special Scientific Interest. There are varying rules for extending properties within these areas, even down to the materials you can use therefore it is worth contacting your local planning department in these cases;
• You are extending near a boundary;

If you are using materials that differ from the original style of the house 

• You are using materials that differ from the original style of the house. Planning policies often require extensions to blend with the character of the existing house and not dominate or overwhelm it. But contrasting styles – such as a contemporary extension on a traditional building – can work well too, so don’t be put off this approach if you think it might work for your property;

Whether it is visible from the street

• Your extension is visible from the street;

If your property listed?

• Your house is listed. Policies for extensions to listed buildings are very restrictive. Limitations might even apply if your property is positioned close to a listed building because any nearby development could be deemed as affecting the setting.

If it impacts on neighbours

• Your extension impacts on your neighbours by creating a loss of light or outlook for them as well as a reduction in in their (or your own) privacy from overlooking windows or gardens;

It is worth noting that the term “original house” means the house as it was first built or as it stood on 1 July 1948 (if it was built before that date). Although you may not have built an extension to the house, a previous owner may have done so.

What is designated land?

It is also worth noting that designated land is land within:

• a conservation area; or
• an area of outstanding natural beauty; or
• an area specified by the Secretary of State for the purposes of enhancement and protection of the natural beauty and amenity of the countryside; or
• the Broads; or
• a National Park; or
• a World Heritage Site

Permitted Development and planning permission rules for an extension vary from time to time. It’s worth visiting the Planning Portal for the most up to date information.

Applying for Planning Permission for an extension

If your scheme doesn’t fit under Permitted Development then you’ll need to submit a full planning application for an extension. By the way, we can take this headache away from you as we offer a full design and planning service. Your local council will have a number of policies in place to manage development in the region, which will govern their decision about whether to approve your extension.

Local Plans will cover guidance for extensions, but the details are sometimes expanded on in supplementary documents or design guides. You might also find information in your Neighbourhood Plan, if there’s one covering your area. If you’re unsure about which policies apply to your project, it always worth contacting your local planning department. The wording in these documents varies greatly from council to council, although there are common planning considerations that apply to all extensions.

You can apply for planning permission for your extension online on the Planning Portal website. If your project needs planning permission and you do the work without getting it, you can be served an ‘enforcement notice’ ordering you to undo all the changes you have made.

How much does a planning application cost?

For home improvers, an application in England for an extension currently costs £206*, whereas in Wales the cost of a typical householder application is currently £190*.

Other things to consider that could affect planning permission for an extension

Extensions can impact on trees (both on your land and potentially even next door). If you’re looking to build close to these, you’ll need to include a tree survey and statement as part of your application. Impacting on greenery that forms a part of the street scene can be a particularly sensitive issue.

Protected species are another thing to look out for. Garden ponds nearby could indicate that great crested newts will be affected by development. An ecological survey will be needed in these cases.
While the presence of sewers and drains isn’t a planning issue, they could influence house layout and/or the cost.

*prices in 2019 so could change