Bi-fold & sliding door openings · Pimlico
Bi-fold & sliding door openings in Pimlico
Bi-fold & sliding door openings for homes in SW1, W1, WC2, designed by a structural engineer.
- Survey, design and installation in one
- Covering SW1, W1, WC2
- Inspected before it is covered
- 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 Pimlico: how it works
Planning bi-fold & sliding door openings in Pimlico? Our team covers SW1, W1 and WC2 and the streets around them. Our coverage runs across London, so nearby villages are included too. You get one written quote for the calculations, approvals, propping, steel and making good.
We coordinate the structure with your door supplier's sizes, so the finished opening matches the frame. The survey visit, structural calculations from a qualified engineer, building control, propping, steel, cavity trays, weather protection while the wall is open and making good are all covered in one itemised written quote.
Worth knowing before you start
- 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.
- Both leaves of a cavity wall need support over the opening. Depending on the design, the outer brickwork may sit on a plate fixed to the beam or on a separate external lintel, and the engineer specifies which suits the loads and the look.
- 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.
How the job runs in Pimlico
Survey in Pimlico
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.
What do bi-fold & sliding door openings cost in Pimlico?
As a guide, budget £3,200–£8,950 including VAT for rear wall opening for bi-fold or sliding doors in Pimlico, 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) |
| Widening an internal doorway | £1,300–£3,200 | Opening widened with a new lintel or short beam, approval where structural, and making good |
| 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 Pimlico
In England, taking out a load-bearing wall or putting in a beam is building work under the Building Regulations 2010. It needs approval from building control, either the local council's building control team or a registered building control approver, through a full plans application or a building notice. Part A covers the structure and Part B covers fire safety, which is why steel in homes is usually fire protected.
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.
Local questions answered
Do you cover Pimlico for bi-fold & sliding door openings?
Yes. We carry out bi-fold & sliding door openings in Pimlico and the SW1, W1 and WC2 postcode districts. Book a free survey visit and we will check the wall, arrange the engineer's calculations and send an itemised written quote.
Do I need a party wall agreement for bi-fold & sliding door openings in Pimlico?
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.
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.
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.
What happens at the survey visit in Pimlico?
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.