Bi-fold & sliding door openings · Kent
Bi-fold & sliding door openings in Kent
Survey, engineer's design and installation of bi-fold & sliding door openings anywhere in Kent.
- Itemised written quote
- Beam sized by a structural engineer
- Covering Kent and nearby
- Free survey visit
- Engineer's calculations arranged
- Building control handled
- Fixed written price once scope is agreed
- England, Wales, mainland Scotland & NI
Planning bi-fold & sliding door openings in Kent
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.
If you are planning bi-fold & sliding door openings in Kent, the order of work matters as much as the steel: survey, calculations, approval, propping, installation, inspection and making good. Coverage takes in Ashford, Sittingbourne and Maidstone and everywhere in between. We run that sequence for you as one job with one point of contact.
What to expect
- 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.
- 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.
- 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.
- 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.
- 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.
How the job runs in Kent
Survey in Kent
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.
How much should I budget in Kent?
As a guide, budget £2,800–£7,850 including VAT for rear wall opening for bi-fold or sliding doors in Kent, based on published UK cost guides adjusted for prices in the South East (+12%).
| Job | Typical guide range | What it usually covers |
|---|---|---|
| Rear wall opening for bi-fold or sliding doors | £2,800–£7,850 | 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) | £900–£2,800 per beam | Beam supplied, delivered, lifted and packed on padstones, with propping (calculations and approval priced separately) |
| Widening an internal doorway | £1,100–£2,800 | Opening widened with a new lintel or short beam, approval where structural, and making good |
| Lintel replacement | £450–£1,340 per lintel | Propping, removing the old lintel, new lintel set on beds and brickwork made good |
Figures include our approximate regional adjustment for prices in the South East (+12%) and are rounded. How these figures are worked out.
Building control and neighbours in Kent
Structural openings in English homes need building regulations approval before work starts. The local council's building control team can deal with it, or you can use a registered building control approver. Either way the steel is inspected before it is covered, and a completion certificate is issued at the end. Keep it safe for when you sell.
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.
Questions about bi-fold & sliding door openings in Kent
Do you cover Kent for bi-fold & sliding door openings?
Yes. We carry out bi-fold & sliding door openings in Kent. Book a free survey visit and we will check the wall, arrange the engineer's calculations and send an itemised written quote.
Can you work on older or listed homes in Kent?
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.
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.
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.
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.
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.