Bi-fold & sliding door openings · Wembley
Bi-fold & sliding door openings in Wembley
Steelwork, approvals and making good for bi-fold & sliding door openings in Wembley and nearby.
- Free survey visit in Wembley
- Engineer's calculations arranged
- Building control handled for you
- Free survey visit
- Engineer's calculations arranged
- Building control handled
- Fixed written price once scope is agreed
- England, Wales, mainland Scotland & NI
Bi-fold & sliding door openings in Wembley: how it works
We cover bi-fold & sliding door openings in Wembley (HA0, HA1, HA3) and the streets around it. We also cover the surrounding towns and villages in London. Each job is designed by a structural engineer and approved through local building control before work begins.
Replacing a window or narrow patio door with a full run of bi-fold or sliding doors opens a room to the garden. Because it is an external wall, the opening usually carries the first floor, the wall above and sometimes roof loads, and the new steel has to work with the doors as well as hold the house up.
What to expect
- The structural work for a typical bi-fold opening usually takes three to five working days. Doors are often made to order, so the steel goes in once opening sizes are confirmed and the doors are fitted soon after.
- Door suppliers quote a structural opening size, which allows for the frame and fixing tolerances. Agreeing that size before the steel is designed avoids reveals that are too tight or gaps that have to be packed out later.
- Glazed doors need a stiffer beam than a plain opening of the same width. If the steel bends even slightly under load, folding panels can bind, sliders can stick and glass can be stressed, so the engineer sets a tighter deflection limit for door openings.
- New glazed doors must meet the energy efficiency requirements of the building regulations, and a wide opening adds a large area of glazing to the house. The door supplier normally provides the performance data that building control needs.
- Level or flush thresholds are popular with bi-fold doors, but the floor inside and the patio outside need planning together. Drainage at the threshold and a proper damp-proof detail stop water running in when the outside is close to floor level.
Four stages, one team
Survey in Wembley
We visit, look at the wall and what sits above it, measure the opening and note services, access and how the steel can be brought in.
Engineer's design
A structural engineer sizes the beam, padstones and any posts, and sets out the temporary support needed while the wall is out.
Building control
We submit a building notice or full plans application to the local council's building control team, so approval is in place before the wall is touched.
Install and sign-off
Props go in, the opening is formed, the steel is set and packed, building control inspects it, and we make good.
Guide prices for bi-fold & sliding door openings in Wembley
As a guide, budget £3,200–£8,950 including VAT for rear wall opening for bi-fold or sliding doors in Wembley, based on published UK cost guides adjusted for London prices (+28%).
| Job | Typical guide range | What it usually covers |
|---|---|---|
| Rear wall opening for bi-fold or sliding doors | £3,200–£8,950 | External wall opened up to about 5 m with steel, propping, cavity tray and making good (doors supplied separately) |
| RSJ supply and fit (single beam) | £1,000–£3,200 per beam | Beam supplied, delivered, lifted and packed on padstones, with propping (calculations and approval priced separately) |
| Opening into a rear extension | £3,200–£8,950 | Original rear wall removed with a beam or goalpost, approvals and propping, coordinated with the extension build |
| Steel goalpost frame | £2,550–£7,700 | Two posts and a beam bolted as a frame, pad foundations, base plates and fitting |
Figures include our approximate regional adjustment for London prices (+28%) and are rounded. How these figures are worked out.
Building rules for Wembley
Structural openings in English homes need building regulations approval before work starts. The local council's building control team can deal with it, or you can use a registered building control approver. Either way the steel is inspected before it is covered, and a completion certificate is issued at the end. Keep it safe for when you sell.
If the beam bears into a wall you share with a neighbour, the Party Wall etc. Act 1996 applies, and a party structure notice must be served at least two months before that work starts. We arrange this through a party wall surveyor.
Questions about bi-fold & sliding door openings in Wembley
Can you work on older or listed homes in Wembley?
Yes. Older homes often have lime mortar, timber lintels or shallow footings, which the engineer allows for. Listed buildings need listed building consent for internal structural changes as well as building regulations approval, and that must be in place first.
Do you also work near Wembley?
Yes. We also cover nearby towns including Harrow, Greenford, Willesden and Northolt.
Will the house be open to the weather while the wall is out?
Only briefly, and it is protected throughout. Once the wall is out, the opening is sheeted or boarded so it stays weathertight and secure until the doors arrive. Timing the structural work close to the door delivery date keeps that period as short as possible.
Should I order my doors before the opening is made?
It helps to choose them first. The supplier's structural opening size and threshold detail feed into the steel design, so the opening is formed to suit the doors exactly. Many people order once the engineer has confirmed the opening, then time the structural work so the gap is weathered for as short a time as possible.
Do I need planning permission for bi-fold doors?
Usually not for a rear opening in a house, as this generally falls within permitted development. Planning or another consent may be needed for front elevations, flats, listed buildings, conservation areas with extra controls, or homes where permitted development rights have been removed. We flag this at survey so you can check before work is booked.
What happens at the survey visit in Wembley?
We look at the wall, the floor and ceiling either side and what sits above, measure the opening you want, and note cables, pipes and access for the steel. It usually takes under an hour and there is no charge.