Bi-fold & sliding door openings · Croydon
Bi-fold & sliding door openings in Croydon
Bi-fold & sliding door openings in Croydon, from free survey to completion certificate.
- Price fixed in writing once scope is agreed
- Building control arranged
- Temporary works and making good included
- Free survey visit
- Engineer's calculations arranged
- Building control handled
- Fixed written price once scope is agreed
- England, Wales, mainland Scotland & NI
About our bi-fold & sliding door openings service in Croydon
We cover bi-fold & sliding door openings in Croydon (CR0, CR2, CR7) and the streets around it. The wider London area is covered as well. 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.
Key points for your project
- 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.
- In cavity walls a cavity tray above the new head directs any water in the cavity out through weep vents. Without it, damp can show inside above the doors, so the tray is lapped and sealed correctly as the brickwork is rebuilt.
- Replacing a rear window with doors in a house is usually permitted development, but front elevations, listed buildings, flats and homes where permitted development rights have been removed may need planning permission or another consent.
- The house is open to the weather between taking out the wall and fitting the doors. Temporary sheeting or a boarded frame keeps rain out and the house secure, so the gap between the structural work and door fitting should be kept short.
- 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.
From survey to sign-off in Croydon
Survey in Croydon
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.
How much should I budget in Croydon?
As a guide, budget £3,200–£8,950 including VAT for rear wall opening for bi-fold or sliding doors in Croydon, 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 |
| Widening an internal doorway | £1,300–£3,200 | Opening widened with a new lintel or short beam, approval where structural, and making good |
Figures include our approximate regional adjustment for London prices (+28%) and are rounded. How these figures are worked out.
Approvals in Croydon
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.
Bi-fold & sliding door openings near Croydon
- South Croydon 1.5 mi
- Wallington 2.7 mi
- Carshalton 3.1 mi
- Mitcham 3.2 mi
- Purley 3.3 mi
- Streatham 3.4 mi
Questions about bi-fold & sliding door openings in Croydon
Do I need a party wall agreement for bi-fold & sliding door openings in Croydon?
Yes, if the beam bears into a shared wall: the Party Wall etc. Act 1996 applies in England and Wales, and a party structure notice must be served at least two months before that work starts. We arrange it through a party wall surveyor.
How much do bi-fold & sliding door openings cost in Croydon?
As a guide, budget £3,200–£8,950 including VAT for rear wall opening for bi-fold or sliding doors in Croydon, based on published UK cost guides adjusted for London prices (+28%). The exact figure depends on the span, what the wall carries, access and the finish, and is fixed in writing once the scope is agreed.
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.
Do I need a steel beam for bi-fold doors?
Usually, yes. Bi-fold and sliding doors need wide openings, and in a load-bearing external wall that span is normally carried on steel. The engineer designs it for strength and stiffness, because glazed doors can stick or be damaged if the beam deflects. A small opening under light loads might only need a lintel, but that is the engineer's call.
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.
What happens at the survey visit in Croydon?
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.