Bi-fold & sliding door openings · Pembrokeshire
Bi-fold & sliding door openings in Pembrokeshire
Survey, engineer's design and installation of bi-fold & sliding door openings anywhere in Pembrokeshire.
- Itemised written quote
- Beam sized by a structural engineer
- Covering Pembrokeshire and nearby
- 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 Pembrokeshire
Bi-fold and sliding door openings are wide gaps formed in an external wall, usually at the back of the house, to take a run of folding or sliding glazed doors. A steel beam carries the wall, floor and roof loads above, and it is designed stiff enough that its movement does not press on the glass or stop the doors running.
Looking for bi-fold & sliding door openings in Pembrokeshire? We work in Tenby, Pembroke and Pembroke Dock and the surrounding villages. Our teams handle the calculations, the building control approval, the propping and the steel itself, and leave the opening ready for plastering and decoration.
Worth knowing before you start
- 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.
- 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.
- 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.
- 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.
Four stages, one team
Free visit
A short visit to Pembrokeshire to see the job, agree what you want and check the bearings, floors and services that affect the design.
Calculations
The engineer's calculations and a simple drawing are prepared for your opening and shared with you before anything is ordered.
Building control
We submit the application or notice to Pembrokeshire County Council under the Building Regulations as they apply in Wales, before work starts.
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 Pembrokeshire?
As a guide, budget £2,300–£6,350 including VAT for rear wall opening for bi-fold or sliding doors in Pembrokeshire, based on published UK cost guides adjusted for prices in Wales (-9%).
| Job | Typical guide range | What it usually covers |
|---|---|---|
| Rear wall opening for bi-fold or sliding doors | £2,300–£6,350 | External wall opened up to about 5 m with steel, propping, cavity tray and making good (doors supplied separately) |
| Lintel replacement | £360–£1,090 per lintel | Propping, removing the old lintel, new lintel set on beds and brickwork made good |
| Steel goalpost frame | £1,800–£5,450 | Two posts and a beam bolted as a frame, pad foundations, base plates and fitting |
| Widening an internal doorway | £910–£2,280 | Opening widened with a new lintel or short beam, approval where structural, and making good |
Figures include our approximate regional adjustment for prices in Wales (-9%) and are rounded. How these figures are worked out.
Building rules for Pembrokeshire
In Wales, structural alterations come under the Building Regulations 2010 as they apply in Wales. Pembrokeshire County Council handles building control for Pembrokeshire. For work started or approved from 1 July 2026, the Welsh system uses an application to building control, dutyholders appointed in writing, a commencement notice before work starts and a compliance statement at the end.
Where the steel bears into a wall shared with next door, notice must be served under the Party Wall etc. Act 1996. If your neighbour dissents, surveyors agree how the work is done before it starts.
Bi-fold & sliding door openings by town
Questions about bi-fold & sliding door openings in Pembrokeshire
How much do bi-fold & sliding door openings cost in Pembrokeshire?
As a guide, budget £2,300–£6,350 including VAT for rear wall opening for bi-fold or sliding doors in Pembrokeshire, based on published UK cost guides adjusted for prices in Wales (-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.
Can I stay at home while the work is done in Pembrokeshire?
Usually, yes. The work area is screened and floors are protected. The rooms either side of the opening are out of action for a few days, and there is some noise and dust while the masonry comes out.
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.
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.
Why does the beam need to be stiffer for glazed doors?
Because glazed doors tolerate very little movement. Every beam bends slightly under load, and with bi-folds or sliders that movement can make panels bind, tracks drag or glass crack. The engineer sets a stricter deflection limit for these openings, which often means a heavier section than strength alone would need.
Can I have a level threshold with bi-fold doors?
Often yes, but it has to be designed. The inside floor, outside paving and drainage all need to work together so water cannot run in, usually with a drainage channel outside and the right damp-proof detail under the door frame. We look at levels at the survey and plan the threshold with the door supplier.
Which towns in Pembrokeshire do you cover?
We cover towns including Haverfordwest, Milford Haven, Pembroke Dock and Tenby, plus the villages and smaller towns around them.