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

Bi-fold & sliding door openings · Horley

Bi-fold & sliding door openings in Horley

Bi-fold & sliding door openings for homes in RH6, designed by a structural engineer.

  • Free survey visit in Horley
  • Engineer's calculations arranged
  • Building control handled for you

Free survey in Horley

Tell us about the bi-fold & sliding door opening job in Horley.

Please enter your name.
Please enter a UK phone number.
Please enter a valid email.
Please enter a UK postcode.
Please tell us a little about the job.
  • 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 Horley

For homes in Horley and the RH6 district, we handle bi-fold & sliding door openings from survey to sign-off. We also work in nearby Crawley, roughly 4.4 miles away. The beam is sized by a structural engineer and inspected before it is boxed in.

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.
  • 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.
  • 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.
  • 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.

From survey to sign-off in Horley

  1. Free visit

    A short visit to Horley to see the job, agree what you want and check the bearings, floors and services that affect the design.

  2. Calculations

    The engineer's calculations and a simple drawing are prepared for your opening and shared with you before anything is ordered.

  3. 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.

  4. Steel in, made good

    On site we prop, open up, fit and pack the steel, then fire protect, box in and plaster once the inspection is done.

How much should I budget in Horley?

As a guide, budget £2,800–£7,850 including VAT for rear wall opening for bi-fold or sliding doors in Horley, based on published UK cost guides adjusted for prices in the South East (+12%).

JobTypical guide rangeWhat it usually covers
Rear wall opening for bi-fold or sliding doors£2,800–£7,850External wall opened up to about 5 m with steel, propping, cavity tray and making good (doors supplied separately)
Widening an internal doorway£1,100–£2,800Opening widened with a new lintel or short beam, approval where structural, and making good
Lintel replacement£450–£1,340 per lintelPropping, removing the old lintel, new lintel set on beds and brickwork made good
RSJ supply and fit (single beam)£900–£2,800 per beamBeam supplied, delivered, lifted and packed on padstones, with propping (calculations and approval priced separately)

Figures include our approximate regional adjustment for prices in the South East (+12%) and are rounded. How these figures are worked out.

Approvals in Horley

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.

Building rules in England

Bi-fold & sliding door openings near Horley

Bi-fold & sliding door openings in Horley: your questions

How soon can bi-fold & sliding door openings start in Horley?

Start dates depend on the engineer's calculations, the building control approval and, where needed, party wall notice periods. We give you a realistic timetable after the survey and keep you updated as each approval comes through.

Can you work on older or listed homes in Horley?

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 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.

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 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.

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.