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

Bi-fold & sliding door openings · Dunbar

Bi-fold & sliding door openings in Dunbar

Bi-fold & sliding door openings for homes in EH42, designed by a structural engineer.

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

Free survey in Dunbar

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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

Bi-fold & sliding door openings in Dunbar: how it works

For homes in Dunbar and the EH42 district, we handle bi-fold & sliding door openings from survey to sign-off. Our coverage runs across East Lothian, so nearby villages are included too. 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.

Worth knowing before you start

  • 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 standards needs.
  • 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.
  • 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.
  • External walls can have gas meters, boiler flues, soil pipes, outside taps or cables near the new opening. These are found at survey and moved by the right trade, with any gas pipework done by a Gas Safe registered engineer as the law requires.
  • 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.

What happens, step by step

  1. 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.

  2. Design and price

    Calculations come back from the engineer and we confirm your fixed written price, line by line.

  3. Building warrant

    A building warrant is applied for from East Lothian Council, and work starts only once the warrant has been granted.

  4. Fit, inspect, finish

    The work is propped and the steel installed and packed tight. After inspection the opening is boxed, plastered and left clean.

How much should I budget in Dunbar?

As a guide, budget £2,300–£6,350 including VAT for rear wall opening for bi-fold or sliding doors in Dunbar, based on published UK cost guides adjusted for prices in Scotland (-9%).

JobTypical guide rangeWhat it usually covers
Rear wall opening for bi-fold or sliding doors£2,300–£6,350External wall opened up to about 5 m with steel, propping, cavity tray and making good (doors supplied separately)
Lintel replacement£360–£1,090 per lintelPropping, removing the old lintel, new lintel set on beds and brickwork made good
RSJ supply and fit (single beam)£730–£2,280 per beamBeam supplied, delivered, lifted and packed on padstones, with propping (calculations and approval priced separately)
Opening into a rear extension£2,300–£6,350Original rear wall removed with a beam or goalpost, approvals and propping, coordinated with the extension build

Figures include our approximate regional adjustment for prices in Scotland (-9%) and are rounded. How these figures are worked out.

Approvals in Dunbar

Scottish rules are stricter on timing than in England: the building warrant must be in place before the wall is touched. We prepare the application with the engineer's calculations and submit it to East Lothian Council. The finished work is then certified and a completion certificate submitted for acceptance.

There is no party wall notice system in Scotland. Instead, check your title deeds and, for flats, the tenement management scheme, and talk to neighbours early if the beam bears into a shared wall.

Building rules in Scotland

Bi-fold & sliding door openings near Dunbar

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

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

As a guide, budget £2,300–£6,350 including VAT for rear wall opening for bi-fold or sliding doors in Dunbar, based on published UK cost guides adjusted for prices in Scotland (-9%). 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.

What happens at the survey visit in Dunbar?

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.

What does a bi-fold opening quote include?

Our itemised written quote covers the survey, calculations, building standards, 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.

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 building regulations for bi-fold doors?

Yes, when you are making a new or wider opening in an external wall, because that is structural work. Building standards also checks the doors meet energy efficiency and safety glazing requirements. In Scotland a building warrant is needed before the work starts. Replacing doors like for like in an existing opening is different and is often handled through an installer's competent person scheme.

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.