Bifold doors are glazed panels that fold and stack to one side to open up a wide gap, while sliding doors glide past each other on tracks; both connect a living space to the garden and bring in more daylight.
Whatever prompted you to look into bifold or sliding doors, whether wear and tear, a growing family or plans to move, we can survey your Harrow home and give you a price in writing. Homes in London typically come in at £3,900–£10,500, VAT included, for this kind of work. We also cover Wealdstone, Brent and Wembley, and the same steps apply wherever you are in London.
- Guide price
- £3,900–£10,500 inc VAT
- Time on site
- 1–2 days to fit into a ready opening
- Postcodes
- HA1, HA2, HA3, HA5 and HA7
- Planning rules
- England
- Local area
- Greater London
- Survey
- Free, with a written quote
Bifold and sliding doors prices in Harrow
Use the table to gauge the cost of bifold or sliding doors in Harrow before we visit. Figures include VAT and are scaled for London, coming out about 30% above the national guide, which gives £3,900–£10,500 overall. After a free survey, you receive a fixed written price.
| Type of job | What it usually involves | Guide in Harrow |
|---|---|---|
| uPVC sliding or French doors | Standard uPVC doors fitted into an existing opening of up to about 2m. | £1,950–£3,900 |
| 3m aluminium bifold | A three-panel aluminium bifold in a standard colour, fitted into a ready opening. | £4,600–£9,100 |
| Wide bifold or slimline slider | Openings of 4m or more and slim-frame doors, often with a new steel above. | £9,100–£18,000 |
Your price depends mostly on:
- Width and height of the opening and number of panels
- Frame material: uPVC, standard aluminium or slimline aluminium
- Widening the opening with a new steel beam
- Threshold type, colour choice and built-in blinds
What does the job include in Harrow?
- Measured survey of the opening, lintel and floor levels
- Toughened double glazing as standard, with solar control options
- Removal of existing doors or windows and disposal of waste
- Level or low threshold options to suit your patio
- Opening widened with a new lintel or steel where agreed
- Weather seals, cills and internal trims finished neatly
Homes in London
London's housing is dominated by Victorian and Edwardian terraces, often in yellow London stock brick, with Georgian terraces in central districts and mansion blocks across many inner areas. Outer boroughs have large belts of interwar semis, and there are extensive post-war council estates. Many houses have been split into flats, and conservation areas are widespread.
London Clay shrinks and swells with the seasons, and street trees close to houses can contribute to movement, which affects foundation design.
In Harrow, as elsewhere in London, we take the building's age and construction into account before recommending anything, because both can change what is involved in bifold or sliding doors.
Do you need permission in Harrow?
For anyone in Harrow, the relevant framework is England's. The summary below is general, so we always contact the council about your address before putting a price in writing.
Replacing windows and doors on a house is usually permitted development in England when the new ones look broadly similar to the old. Flats, listed buildings and homes covered by an Article 4 direction can need consent, and conservation areas may limit materials or styles.
Replacement windows and external doors must meet Building Regulations for energy efficiency, ventilation and, on upper floors, escape. The work is either self-certified by an installer registered with a competent person scheme or signed off by building control.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
The four stages
Free site survey
Book a visit and we'll come to you. The survey covers measurements, the state of what's there now and any obvious constraints, so the price that follows is based on your actual home, not an average.
Quote in writing
The quote arrives in writing, not over the phone. It covers the full scope, the finishes you've chosen, any exclusions and the payment schedule, with a fixed price tied to that specification.
Booking the work
Once you accept, we agree start dates, order materials and deal with any planning, building control or neighbour notices the job needs. You'll know who is coming and when before work begins.
Finish and handover
The job proceeds in the order set out in the programme, with dust and debris kept under control. Finally we tidy away, inspect the work together and pass the finished project over to you with its paperwork.
How we work
Common questions
How long will bifold or sliding doors take?
On a typical home, allow 1–2 days to fit into a ready opening. Larger projects, older buildings and extra work found once things are opened up can extend that, while simpler jobs may be shorter. Your quote includes an estimate of time on site, and your point of contact keeps you updated on the programme as the work progresses.
Will large glass doors make my room cold?
Large glass doors lose more heat than an insulated wall, but modern double glazing with thermally broken frames performs far better than older patio doors. Solar control glass helps stop south-facing rooms overheating in summer. In extensions, building control looks at the total glazed area, so heat-loss calculations may be needed. We can suggest glass specifications that balance light, warmth and cost.
How much do bifold doors cost?
Bifold doors cost £3,900–£10,500 for a typical 3m opening, supplied and fitted. As a rough guide, allow around £900–£2,000 per metre of width plus the fixed costs of fitting, depending on frame material and glass. uPVC sits at the lower end and slimline aluminium at the top. Widening the opening with a new steel adds to the price. We confirm a fixed figure after measuring.
Do you cover Wealdstone, Brent and Wembley?
Yes. As well as Harrow, we cover Wealdstone, Brent and Wembley and the rest of London. Our coverage is UK-wide, so the process is the same wherever you are: a free site survey, a quote in writing that fixes the price for the agreed scope, and one point of contact while the work is planned and carried out.
Are bifold doors secure?
Modern bifold and sliding doors are designed to be secure, with multi-point locks, shoot bolts into the frame, internally beaded glass and toughened or laminated glazing. The traffic door, which you use day to day, has a cylinder lock that can take an anti-snap barrel. Sliding doors also have anti-lift features. We explain the locking on each option so you can compare like for like.
Near Harrow
Our coverage in Harrow includes HA1, HA2, HA3 and HA5. We also travel to Wealdstone, Brent and Wembley, so neighbouring addresses are looked after on exactly the same terms as those in town.

