Bi-fold & sliding door openings · Portsmouth
Bi-fold & sliding door openings in Portsmouth
Bi-fold & sliding door openings in Portsmouth, from free survey to completion certificate.
- Free survey visit in Portsmouth
- Engineer's calculations arranged
- Building control handled for you
- 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 Portsmouth
Planning bi-fold & sliding door openings in Portsmouth? Our team covers PO1, PO2, PO3, PO4 and PO5 and the streets around them. The wider Hampshire area is covered as well. 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.
What to expect
- 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.
- 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.
- 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.
- 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.
From survey to sign-off in Portsmouth
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.
Design and price
Calculations come back from the engineer and we confirm your fixed written price, line by line.
Building control
We submit a building notice or full plans application to Portsmouth City Council, so approval is in place before the wall is touched.
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 Portsmouth?
As a guide, budget £2,800–£7,850 including VAT for rear wall opening for bi-fold or sliding doors in Portsmouth, 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) |
| Opening into a rear extension | £2,800–£7,850 | Original rear wall removed with a beam or goalpost, approvals and propping, coordinated with the extension build |
| Lintel replacement | £450–£1,340 per lintel | Propping, removing the old lintel, new lintel set on beds and brickwork made good |
| Steel goalpost frame | £2,250–£6,700 | Two posts and a beam bolted as a frame, pad foundations, base plates and fitting |
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 Portsmouth
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 Portsmouth City 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.
Terraced and semi-detached homes often need party wall notices, because cutting into a shared wall to take a beam end is notifiable under the Party Wall etc. Act 1996. Allow at least two months for the notice period unless your neighbour agrees sooner.
Bi-fold & sliding door openings near Portsmouth
- Gosport 1.7 mi
- Fareham 5.3 mi
- Havant 6.1 mi
- Waterlooville 6.2 mi
- Chichester 13.8 mi
- Hythe 14.2 mi
Local questions answered
Do you cover Portsmouth for bi-fold & sliding door openings?
Yes. We carry out bi-fold & sliding door openings in Portsmouth and the PO1, PO2, PO3, PO4 and PO5 postcode districts. Book a free survey visit and we will check the wall, arrange the engineer's calculations and send an itemised written quote.
Do you also work near Portsmouth?
Yes. We also cover nearby towns including Gosport, Fareham, Havant and Waterlooville.
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.
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.
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.
Can you work on older or listed homes in Portsmouth?
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.