Steel BeamInstallers
Rear wall opened for wide doors with a galvanised steel beam and props, garden beyond

Bi-fold & sliding door openings · Chippenham

Bi-fold & sliding door openings in Chippenham

Bi-fold & sliding door openings in Chippenham, from free survey to completion certificate.

  • Itemised written quote
  • Beam sized by a structural engineer
  • Covering Chippenham and nearby

Free survey in Chippenham

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  • 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 Chippenham

Planning bi-fold & sliding door openings in Chippenham? Our team covers SN14 and SN15 and the streets around them. We also work in nearby Bath, roughly 11.8 miles away. You get one written quote for the calculations, approvals, propping, steel and making good.

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

  • 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.
  • Very wide openings, or ones that run close to the corner of the house, may leave too little wall for the beam to bear on. In that case the engineer may specify steel columns or a goalpost frame standing on its own foundations.
  • Width, what sits above, whether columns or a goalpost are needed, outer leaf support, threshold works and how much brickwork needs matching all affect the price. The doors themselves are normally supplied separately unless agreed otherwise.
  • 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.

What happens, step by step

  1. Survey in Chippenham

    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.

  2. 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.

  3. Building control

    We submit a building notice or full plans application to Wiltshire Council, so approval is in place before the wall is touched.

  4. 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 Chippenham?

As a guide, budget £2,600–£7,200 including VAT for rear wall opening for bi-fold or sliding doors in Chippenham, based on published UK cost guides adjusted for prices in the South West (+3%).

JobTypical guide rangeWhat it usually covers
Rear wall opening for bi-fold or sliding doors£2,600–£7,200External wall opened up to about 5 m with steel, propping, cavity tray and making good (doors supplied separately)
Lintel replacement£410–£1,240 per lintelPropping, removing the old lintel, new lintel set on beds and brickwork made good
Widening an internal doorway£1,050–£2,600Opening widened with a new lintel or short beam, approval where structural, and making good
Structural calculations for a beam£260–£770Site measure or photos, beam and padstone design and calculations for building control

Figures include our approximate regional adjustment for prices in the South West (+3%) and are rounded. How these figures are worked out.

Approvals in Chippenham

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 Wiltshire Council 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.

Building rules in England

Bi-fold & sliding door openings near Chippenham

Questions about bi-fold & sliding door openings in Chippenham

How much do bi-fold & sliding door openings cost in Chippenham?

As a guide, budget £2,600–£7,200 including VAT for rear wall opening for bi-fold or sliding doors in Chippenham, based on published UK cost guides adjusted for prices in the South West (+3%). 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 a party wall agreement for bi-fold & sliding door openings in Chippenham?

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.

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.

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.

Do you also work near Chippenham?

Yes. We also cover nearby towns including Trowbridge, Bath, Yate and Swindon.

Planning to take a wall out?

Book a free survey visit. You get an itemised written quote covering calculations, building control, steel and making good.