Cost to install bifold doors: what the job involves and who is registered to do it

How cost to install bifold doors works

1. Establish whether the opening exists. This single question decides most of the price. An existing opening of the right size makes bifolds a supply and fit job. A new or widened opening needs a lintel or steel sized by somebody competent, temporary support while it goes in, and building control involvement, and that work is typically a large share of the total.
2. Count the panes and pick the stacking. Bifolds are priced per leaf, so a wide opening in more leaves costs more than the same opening in fewer, larger ones. Which way the leaves fold, which side they stack, and whether one leaf works as a normal door for everyday use all change the specification and the price.
3. Decide the threshold before the floor. A low or flush threshold looks better and is easier to walk through, but it has to be detailed properly for drainage and weather. That detail affects the floor build up inside and any drainage channel outside, so it needs settling before the floor is laid rather than afterwards.
4. Choose the material for the sightline. Aluminium is the usual choice for bifolds because the frames can be slim while still carrying the weight and the running gear. uPVC and timber are available and behave differently in wide openings. The visible difference between systems is mostly the width of the frame you see when the doors are shut.
5. Confirm who signs the work off. New glazing is notifiable, and structural work to form an opening is building control work in its own right. Establish early whether the door installer's registration covers the glazing only, and who is responsible for the structural element, so nothing falls between two trades.

Insurance and paperwork

Common questions

Do bifold doors need planning permission?

Changing doors in an existing opening usually does not, but forming a new opening in a rear wall, and any work to a listed building or in a conservation area, can. The local authority is the only reliable answer and the question is cheap to ask early.

Are bifolds or sliding doors cheaper to install?

They are priced differently rather than one being reliably cheaper. Bifolds are priced by leaf and sliders by panel and glass size, so the comparison shifts with the width of the opening and the specification you want.

What maintenance do the running gear and tracks need?

Bifolds have more moving parts than a hinged door and the bottom track collects grit, which is what wears rollers. Keeping the track clear and having the gear adjusted periodically is the difference between doors that keep working and doors that start to bind.

Registered contractors by region

• Registered roofers in the East Midlands postcode area
• Registered roofers in the East of England postcode area
• Registered roofers in the London postcode area
• Registered roofers in the North East postcode area
• Registered roofers in the North West postcode area
• Registered roofers in the Scotland postcode area
• Registered roofers in the South East postcode area
• Registered roofers in the South West postcode area
• Registered roofers in the Wales postcode area
• Registered roofers in the West Midlands postcode area
• Registered roofers in the Yorkshire and The Humber postcode area