Do I Need Planning Permission for Bifold Doors?

Usually not. Fitting bifold doors into the wall of a house is an alteration rather than an enlargement, so it sits inside Class A of the permitted development order and on most houses no planning application is made.

What that answer does not cover is the more expensive half of the job. Permitted development says nothing about the beam holding the wall up above the doors, nothing about a condition on your original permission that may have removed the right years ago, and nothing at all if the property is a flat.

Why doors are an alteration and not an extension

Nothing projects, so almost none of the limits you have already read about are engaged.

Class A permits the enlargement, improvement or other alteration of a house. Bifolds are the third of those. Because no part of the building moves outward, the limits that dominate every other permitted development conversation attach to an enlarged part that does not exist here: the rear projection depths, the half the width test for side extensions, the 50 per cent ground cover calculation. None of them has anything to measure.

Widening a rear opening from a window to a four metre hole is still an alteration, and so is cutting a new opening through solid brickwork. The wall is being altered rather than moved, and the order treats those as different things.

There is a step before Class A as well. Works that do not materially affect the external appearance of a building are not development at all, so swapping a door set for another of much the same appearance in the same opening never reaches the point of needing a permitted development right.

The conditions that can bite

Only a handful are attached to Class A, and two of them are worth knowing before you place the order.

• Materials similar in appearance to the existing house. Existing, not original, so the reference is the house as it stands today including whatever a previous owner added. Similar is a lower bar than identical, but a dark aluminium screen dropped into a run of white plastic windows is a judgement rather than an automatic pass.
• Upper-floor windows in a side elevation must be obscure glazed and non-opening below 1.7 metres. The condition covers a window in a wall or in a roof slope forming a side elevation. Ground floor doors sit outside it entirely, which is where bifolds nearly always go, but a first floor set onto the flank of the house does not.
• No verandas, balconies or raised platforms. This is the one that catches door projects. A Juliet arrangement, with guarding fixed across the opening and nothing to stand on, is generally not a balcony. A terrace or deck outside the doors that stands more than 300mm above the ground is a raised platform, and the platform falls outside Class A even though the doors did not. People discover this after the deck is built.

What a conservation area actually changes

Less than almost everybody expects, and the restrictions it does impose are not about doors.

Article 2(3) land covers conservation areas, National Landscapes, which the legislation still calls areas of outstanding natural beauty, National Parks, the Broads and World Heritage Sites, and it does cut Class A back. It prohibits cladding the exterior in the materials it lists, which run from stone and pebble dash to render, timber, plastic and tiles, it removes side extensions, and it removes rear extensions of more than a single storey. A set of doors in an existing wall is none of those, so bifolds inside a conservation area boundary generally remain permitted development in the same way as anywhere else.

The instrument that genuinely takes them away is an Article 4 direction. Windows and doors are exactly what those are made for, because the character of a historic street is carried in its joinery more than in anything else on the elevation. A direction applies to a defined area and names the classes it withdraws, so the only check worth doing is against your own address rather than against the town, and the council will confirm it at no cost.

Listing adds a consent, it does not remove one

A listed building keeps its Part 1 rights. What listing adds is listed building consent, a separate regime under separate legislation, covering work that affects the character of the building as one of special architectural or historic interest, inside as well as out. Doing that work without consent is a criminal offence rather than a matter for an enforcement notice, which is why the second consent is in practice much the harder of the two. A wide aluminium screen cut into a historic rear elevation is a difficult application, and it usually turns on what is being removed rather than on what is going in.

What does remove the right

• Flats and maisonettes. Part 1 applies to dwellinghouses, and the definition excludes a flat and a building containing flats. There is no Class A to rely on, so any change to the external appearance is an application, and the lease will usually have something to say too.
• A condition on an earlier planning permission. Common on estate housing built from the 1980s onwards, and almost nobody checks. It takes ten minutes on the council’s planning search.
• A house created by a change of use. Where the dwelling exists only by virtue of the change of use classes, a converted barn, office or shop, Class A does not apply to it at all.

Covenants on the title are a separate matter again. They are private law rather than planning, so the council will not look at them and will happily confirm permitted development for something your deeds forbid.

The approvals that do apply

Planning is the part of this job least likely to cause trouble.

The opening is the real event. A four metre hole in a loadbearing wall needs a beam sized for deflection as well as strength, because a beam that is safe can still sit down far enough on the frame to stop the doors locking. How the beam is sized and where it bears covers that, and where it bears into a shared wall the Party Wall Act brings its own notice period with it.

Building Control is engaged whichever way planning falls. Doors are controlled fittings with a thermal standard to meet, judged on the whole door rather than the centre of the glass, and full height glazing sits in a critical location and has to be safety glass. The room also still needs its background ventilation once the window that used to provide it has gone, and if that window was the escape route, whatever replaces it has to carry on doing that job.

The practical answer

On an ordinary house, in an ordinary street, order the doors. Before you do, check three things: the planning history of the address for a condition, whether any direction covers the property, and the deeds. If the answer matters, a lawful development certificate turns it into a document a buyer’s solicitor will accept in fifteen years’ time.

Which doors go in the hole once you know you can have them is a different question, and how much of the opening each type actually clears is where that one is worked through.

Permitted development conditions are amended from time to time and how they apply depends on your property, its designation and its planning history. Treat this as an explanation of the system rather than as confirmation of what you can install.

Last reviewed August 2026.