A Guide to Building Regulations for Bifold Doors

Bifold doors are a great way to open your home into your garden. They are often used to create a transition between the inside of your property and a patio or decking. Bifold doors have to meet building regulations. There are different ways of doing this. There are also different building regulations which might apply. The precise way that building regulations will apply will depend on your property and the type of bifold door that you’re installing. So read on to find out more about the building regulations that may apply.

What are building regulations?

Building regulations set out standards that building work has to meet. The government sets these standards. They apply to new homes and many kinds of refurbishment and renovation work. The building regulations make sure that buildings are safe and environmentally friendly. They do this by setting standards for a wide range of areas, such as structural stability, ventilation and fire safety.

Building regulations and bifold doors

Bifold doors will have to meet building regulations. The building regulations will usually apply whether you are replacing an existing door or fitting a new bifold door. However, the range of building regulations that your installation has to meet may be different. The best way to make sure that your bifold doors meet building regulations is to use a registered installer. These installers will be able to self-certify that their work meets building regulations. There are several organisations which provide this certification, such as FENSA or CERTASS.

These regulations only apply to external bifold doors. So if your bifold door is entirely internal, you only need to adhere to a set of relaxed regulations.

Some of the building regulations which may apply to your bifold door installation are:

Insulation and thermal efficiency

Properties have to meet strict energy efficiency targets. If you replace doors and windows, the replacements will need to meet these targets. The building regulations set out standards which bifold doors will have to meet. The rate of heat loss is measured as a U-value. In general, bifold doors will have to meet a U-value of 1.8. There are also letter grade ratings for glazing. The minimum standard you can use is E rated glazing. Using higher rated glazing will improve the thermal performance of your bifold doors.

If you install bifold doors in a room or area which already has lots of glazing, you may need to meet different building regulations. These will usually only apply in rooms with existing large windows or roof lights, or in glass conservatories. So in these cases, it’s best to speak to professional double glazing companies or your local authority for advice.

If your bifold doors are part of a home extension or conversion, you may need to revisit the insulation of your entire home. This is because the property must meet thermal efficiency targets. You may be able to offset the impact of bifold doors by upgrading insulation elsewhere, for example in the loft.

Fire safety

Bifold doors will not usually affect the fire safety requirements. However, you may need to show that rooms have acceptable means of escape. There are also restrictions on the number of doors in a property which are ‘unprotected’. Unprotected doors are doors which do not self-close. In general, this will only apply if your bifold door is against a property boundary or a neighbouring wall.


The building regulations establish minimum standards for home security. For bifold doors, this will mean ensuring that the locking mechanisms meet British Standards. These locking mechanisms should feature multi-point locking. Typically you’ll need at least 5 point locking. Glazing on bifold doors should also be internally beaded to prevent the glass from being forced out.


Bifold doors will usually need ventilation. This is generally achieved by including trickle vents into the design of the door. These provide passive airflow to the room.

Structural stability

As bifold doors can require additional support or add extra load to a building, you may have to make extra structural alterations. This could involve adding a lintel or RSJ above the bifold doors to add extra support. Speak to a structural surveyor for advice if you’re concerned about structural issues with your bifold door installation.

Overall, the building regulations are complicated. You should always seek advice from an experienced bifold door installer or your local authority. The way the regulations apply will depend on the specifics of your installation and your property.