Rear extension steels · Derry City and Strabane
Rear extension steels in Derry City and Strabane
Rear extension steels across Derry City and Strabane, designed by a structural engineer and signed off by building control.
- Itemised written quote
- Beam sized by a structural engineer
- Covering Derry City and Strabane 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 rear extension steels in Derry City and Strabane
Rear extension steels are the beams, columns and frames that let the original back wall of a house be opened up into a new extension. Sized by a structural engineer, they pick up the floor, wall and roof loads that the old wall carried and pass them into bearings or foundations, so the new and old spaces join as one open room.
We carry out rear extension steels throughout Derry City and Strabane, for homeowners, landlords and builders who need the structural part done properly. That includes Derry/Londonderry and Strabane, plus smaller towns and villages nearby. You get an itemised written quote that shows the calculations, approvals, steel, labour and finishing as separate lines.
What to expect
- When bi-fold or sliding doors sit directly beneath the new steel, the beam has to stay stiff enough not to bind the door panels. The engineer sets a tighter deflection limit, which can mean a deeper or heavier section than strength alone would need.
- A single beam works where solid masonry is left at both ends of the opening. Where the opening runs nearly the full width or the corners are weak, the engineer may use columns or a goalpost frame, which is two posts and a beam bolted together.
- The building control completion certificate for the extension covers the steelwork to the old rear wall. Keep it with the engineer's calculations and drawings, as a buyer's solicitor will expect to see the structural paperwork for the extension.
- The opening is usually formed once the extension walls and roof are up, so the house stays secure and dry. Leaving it too late can hold up plastering and floor screeding, so the steel date is agreed with the builder early on.
- The original rear wall of most houses is load-bearing because it supports first-floor joists and the bedroom wall above. Even where the joists run parallel to it, the masonry overhead still needs carrying, so steel is almost always part of opening it up.
How the job runs in Derry City and Strabane
Free visit
A short visit to Derry City and Strabane 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
A full plans application or building notice goes to Derry City and Strabane District Council under the Building Regulations (Northern Ireland) 2012 before work begins.
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.
What do rear extension steels cost in Derry City and Strabane?
As a guide, budget £2,150–£6,000 including VAT for opening into a rear extension in Derry City and Strabane, based on published UK cost guides adjusted for prices in Northern Ireland (-14%).
| Job | Typical guide range | What it usually covers |
|---|---|---|
| Opening into a rear extension | £2,150–£6,000 | Original rear wall removed with a beam or goalpost, approvals and propping, coordinated with the extension build |
| Steel column or post | £430–£1,290 per column | Column supplied and fitted with base and cap plates on a pad foundation |
| Rear wall opening for bi-fold or sliding doors | £2,150–£6,000 | External wall opened up to about 5 m with steel, propping, cavity tray and making good (doors supplied separately) |
Figures include our approximate regional adjustment for prices in Northern Ireland (-14%) and are rounded. How these figures are worked out.
Approvals in Derry City and Strabane
Building control in Derry City and Strabane is run by Derry City and Strabane District Council. Beams and new openings are controlled work under the Northern Ireland regulations, so we apply before anything is removed and the steel is inspected before it is covered.
The Party Wall etc. Act does not extend to Northern Ireland. Shared walls are dealt with under your title and the general law, so we recommend agreeing access and the work with your neighbour before it starts.
Rear extension steels by town
Local questions answered
Can I stay at home while the work is done in Derry City and Strabane?
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.
Who approves rear extension steels in Derry City and Strabane?
Structural work in Derry City and Strabane needs a full plans application or building notice to Derry City and Strabane District Council. We prepare and submit it with the structural engineer's calculations and arrange the inspections, so the completion paperwork follows the job.
How wide can a rear extension opening be?
There is no fixed limit, and openings across the full width of a house are common with the right steel. The engineer sizes the beam or frame for the span and the loads above. Wider spans need deeper or heavier steel and possibly columns, which affects headroom and cost.
When does the back wall come out during an extension build?
Usually once the extension walls and roof are up and the new space is weathertight. That keeps the house secure and dry while the opening is formed. The steel goes in, building control inspects it, and the builder then carries the floors and ceilings through.
Will my kitchen be out of action while the rear wall is opened?
For a few days, usually. The kitchen often sits against the rear wall, so units, sinks or appliances near the opening may need disconnecting while the wall is propped and removed. The work area is sheeted off and the rest of the house stays in use.
Can I use my own builder for the extension and you for the steels?
Yes. We can supply and fit the steel package while another builder handles the extension shell and finishes. Dates are agreed with them so the rear wall is opened at the right stage, and the engineer's details are shared so levels, padstones and foundations line up.
Which towns in Derry City and Strabane do you cover?
We cover towns including Derry/Londonderry and Strabane, plus the villages and smaller towns around them.