Bi-fold & sliding door openings · Cricklewood
Bi-fold & sliding door openings in Cricklewood
Bi-fold & sliding door openings for homes in NW2, NW3, NW4, designed by a structural engineer.
- 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
What bi-fold & sliding door openings involve in Cricklewood
Our bi-fold & sliding door openings service in Cricklewood covers everything from the first visit to the completion paperwork. The wider London area is covered as well. Postcode districts we cover here include NW2, NW3, NW4, NW6 and NW10.
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.
Things to plan for
- A wide glazed opening changes the security of the back of the house. During the works the opening is boarded at night if the doors are not yet fitted, and it is worth checking the locking and glass specification of the doors you choose.
- 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.
- New brickwork at the reveals and above the opening should match the existing in colour, size and bond. Sound bricks from the wall being removed are often cleaned and reused, and the mortar colour is matched as closely as possible.
- 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.
- 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.
What happens, step by step
Look and measure
We check the wall, the span you want and what the wall is carrying, and photograph anything the engineer needs to see.
Design and price
Calculations come back from the engineer and we confirm your fixed written price, line by line.
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.
Fit, inspect, finish
The work is propped and the steel installed and packed tight. After inspection the opening is boxed, plastered and left clean.
Guide prices for bi-fold & sliding door openings in Cricklewood
As a guide, budget £3,200–£8,950 including VAT for rear wall opening for bi-fold or sliding doors in Cricklewood, 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) |
| Steel goalpost frame | £2,550–£7,700 | Two posts and a beam bolted as a frame, pad foundations, base plates and fitting |
| 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) |
| Lintel replacement | £510–£1,540 per lintel | Propping, removing the old lintel, new lintel set on beds and brickwork made good |
Figures include our approximate regional adjustment for London prices (+28%) and are rounded. How these figures are worked out.
Approvals in Cricklewood
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 Cricklewood
- Kilburn 1.1 mi
- Willesden 1.8 mi
- Chalk Farm 3.0 mi
- Notting Hill 3.2 mi
- Finchley 3.2 mi
- Camden Town 3.3 mi
Bi-fold & sliding door openings in Cricklewood: your questions
What happens at the survey visit in Cricklewood?
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.
Do I need a party wall agreement for bi-fold & sliding door openings in Cricklewood?
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 wide can a bi-fold door opening be?
There is no fixed limit, as it depends on the loads above and what the beam can bear on. The engineer designs the steel and, for very wide openings or ones near a corner, may specify columns or a goalpost frame. The door system's own maximum panel sizes and configurations also need checking.
What does a bi-fold opening quote include?
Our itemised written quote covers the survey, calculations, building control, propping, removing the wall, steel and padstones, outer leaf support, cavity trays and closers, temporary weather protection and making good. Doors, threshold drainage and patio work are shown separately unless agreed. The price is fixed in writing once the opening size and specification are agreed.
How long does it take to make an opening for bi-fold doors?
The structural opening usually takes three to five working days, including propping, cutting out the wall, fitting the steel and outer leaf support, and forming the reveals. The doors can then be fitted, with inside making good and outside brickwork finishing following on. Lead times on made-to-order doors affect the overall timeline more than the steelwork.