How far can you extend a bungalow without planning permission?

For a single storey rear extension, the Planning Portal sets these limits:

• no more than 4 metres beyond the original rear wall for a detached house, or 3 metres for any other house
• no more than 4 metres high
• no higher than the highest part of the existing roof, and the eaves no higher than the existing eaves
• eaves no higher than 3 metres if any part of the extension is within 2 metres of a boundary
• materials of a similar appearance to the existing house
• extensions and other buildings must not cover more than half the land around the original house

The eaves rule matters more on a bungalow than on most houses. The government's technical guidance measures the new eaves against the highest eaves of the existing house, and a bungalow's eaves sit at single storey height, so this is often the limit that decides how tall a permitted development extension can be.

If you want to go further back, you can ask the council for prior approval to build up to 8 metres on a detached house or 6 metres on any other house, as long as the property is not on designated land or a Site of Special Scientific Interest. We explain how that process works in our guide to prior approval for a larger home extension.

Side extensions to a bungalow

A side extension can go ahead under permitted development if it is single storey, no more than 4 metres high and no wider than half the width of the original house. On designated land, every side extension needs householder planning permission.

Does a bungalow loft conversion need planning permission?

Often it does not. Converting a bungalow loft, including adding dormers to make what many people call a dormer bungalow, can be permitted development if it meets the Planning Portal's conditions:

• the extra roof space is no more than 50 cubic metres, or 40 cubic metres for a terraced house, counting any earlier roof extensions
• nothing goes beyond the existing roof slope on the principal elevation that faces a highway, so a dormer on the front of a bungalow facing the road needs planning permission
• nothing is higher than the existing roof
• materials are similar in appearance to the existing house
• there are no verandas, balconies or raised platforms
• side-facing windows are obscure-glazed, and any that open are at least 1.7 metres above the floor
• the enlargement is set back, as far as practicable, at least 20cm from the original eaves

Homes on designated land do not have these loft rights. The technical guidance also says the parts of a hip to gable enlargement do not have to meet the conditions on keeping the original eaves and the 20cm set back.

Because nothing can be higher than the existing roof, the useful space you gain depends on the height and pitch of your roof. That is a design question to settle early, before you assume the loft will work.

Can you add a second storey to a bungalow?

There is a separate permitted development right, Class AA in the General Permitted Development Order, for building additional storeys on top of an existing house. For a house of one storey, it allows one additional storey. It does not apply if:

• the house was built before 1 July 1948 or after 28 October 2018
• the property is on Article 2(3) land or a Site of Special Scientific Interest
• the house has already been extended by adding storeys
• the highest part of the roof would rise by more than 3.5 metres, or end up more than 18 metres high
• the new storey's floor to ceiling height would be more than 3 metres, or more than that of the existing storey

There are extra height limits if the bungalow is semi-detached or terraced. The new storey must use materials of a similar appearance, have no windows in the side walls and match the existing roof pitch. Before you build, you must apply to the council for prior approval and provide a construction management report. The matters the council considers include the impact on neighbours (overlooking, privacy and loss of light) and the external appearance of the house. The work must be finished within 3 years of the date prior approval is granted, and you must tell the council in writing when it is complete.

If your bungalow does not qualify for Class AA, or you want something the rules do not allow, adding a storey needs a planning application. Our guide to the householder planning application explains how that process works.

Bungalows in the Green Belt

Green Belt is not on the list of designated land in the permitted development rules, so a bungalow in the Green Belt usually keeps its permitted development rights. Where a planning application is needed, national policy says an extension in the Green Belt should not result in a disproportionate increase in size compared with the original building, meaning the building as it was on 1 July 1948 or as it was first built.

This is something we explain often in the free planning reports we send to bungalow owners in the Green Belt: the council compares the proposal with the original bungalow (as it stood on 1 July 1948, or as first built if later), not with the bungalow as it is today, so earlier extensions use up some of the room to grow. Because of that, we usually start by checking what could go ahead under permitted development and suggest confirming it with a lawful development certificate. Once granted, work carried out as the certificate describes is presumed lawful, unless there is a material change, such as an Article 4 direction removing the relevant rights, before work begins.

What we ask for before advising on a bungalow

Before we confirm the route for a bungalow project, we ask for a few phone photos of the front, the back and the roof, how close the neighbours are, and roughly when the bungalow was built. The build date matters because it decides whether the extra storey right can apply at all, and the photos usually show straight away whether the front of the roof faces a road and how much height the roof has to work with.

Frequently asked questions

Can I put a dormer on the front of my bungalow without planning permission?

Not if the front of the roof is the principal elevation facing a highway. Permitted development does not allow a roof enlargement beyond the existing roof slope there, so a front dormer facing the road needs planning permission. Rear and side dormers can be permitted development within the volume and other limits.

Can I add a first floor to my bungalow without planning permission?

Possibly, under Class AA, if the bungalow was built between 1 July 1948 and 28 October 2018, is not on designated land and the new storey meets the height and design limits. You still need prior approval from the council before you start.

Do I still need building regulations approval?

Building regulations are a separate matter. Permitted development and a lawful development certificate cover planning only. A certificate does not remove the need to comply with other legal requirements, such as the Building Regulations.

Talk it through with us

The right route for a bungalow depends on its age, where it is and what has been added over the years. If you would like a second opinion before you commit to drawings, book a free advice call and we will talk through your options.