
Rear extension steels · Mid and East Antrim
Rear extension steels in Mid and East Antrim
Survey, engineer's design and installation of rear extension steels anywhere in Mid and East Antrim.
- Survey, design and installation in one
- Covering BT38, BT40, BT42, BT43
- Inspected before it is covered
- Free survey visit
- Engineer's calculations arranged
- Building control handled
- Fixed written price once scope is agreed
- England, Wales, mainland Scotland & NI
What rear extension steels involve in Mid and East Antrim
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.
If you are planning rear extension steels in Mid and East Antrim, the order of work matters as much as the steel: survey, calculations, approval, propping, installation, inspection and making good. That includes Carrickfergus, Ballymena and Larne, plus smaller towns and villages nearby. We run that sequence for you as one job with one point of contact.
Worth knowing before you start
- Columns carry concentrated loads, so each normally sits on a pad foundation designed by the engineer. Digging these inside an existing kitchen or through a solid concrete floor takes planning, especially where drains run close to the back wall.
- Opening the rear wall is usually the dustiest stage of an extension project. The work face is sheeted off from the rest of the house, and the kitchen is often out of use for a few days while the opening is formed and the steel goes in.
- Two-storey rear extensions add a second level of loads to think about. Steels at first-floor level may carry the existing rear wall of the bedrooms or tie the new roof into the old one, so the engineer looks at both floors 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 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.
From survey to sign-off in Mid and East Antrim
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
A full plans application or building notice goes to Mid and East Antrim Borough Council under the Building Regulations (Northern Ireland) 2012 before work begins.
Fit, inspect, finish
The work is propped and the steel installed and packed tight. After inspection the opening is boxed, plastered and left clean.
What do rear extension steels cost in Mid and East Antrim?
As a guide, budget £2,150–£6,000 including VAT for opening into a rear extension in Mid and East Antrim, 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 goalpost frame | £1,700–£5,150 | Two posts and a beam bolted as a frame, pad foundations, base plates and fitting |
| Side return extension steelwork | £3,000–£7,300 | Beams and posts along the old side wall line, propping and approvals (extension build extra) |
| 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.
Building rules for Mid and East Antrim
Removing a load-bearing wall in Northern Ireland needs building control approval from the council. Mid and East Antrim Borough Council covers Mid and East Antrim. The engineer's calculations support the application, and a completion certificate is issued after the final inspection.
Northern Ireland has no Party Wall Act, so there is no statutory notice to serve. Where the steel bears into a shared wall, the title deeds and the general law apply, and agreeing the work with your neighbour in writing first is good practice.
Rear extension steels by town
Local questions answered
Who approves rear extension steels in Mid and East Antrim?
Structural work in Mid and East Antrim needs a full plans application or building notice to Mid and East Antrim Borough Council. We prepare and submit it with the structural engineer's calculations and arrange the inspections, so the completion paperwork follows the job.
Which towns in Mid and East Antrim do you cover?
We cover towns including Carrickfergus, Ballymena and Larne, plus the villages and smaller towns around them.
Do I need a steel beam for my rear extension?
If the original back wall is being opened up into the extension, almost certainly yes. That wall normally carries the first floor and the wall above, so a beam, columns or a goalpost frame takes over the job. A structural engineer confirms exactly what is needed once the opening width and loads are known.
What is a goalpost frame in an extension?
A goalpost frame is two steel columns with a beam across the top, bolted together and standing on their own foundations. It is used where the opening is so wide that little masonry is left to bear on, or where the existing corners cannot take the load. The engineer decides whether one is needed.
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.
Can I have a flat ceiling between the house and the extension?
Often, yes, but it depends on the floor depth above and the loads involved. The steel can sometimes be set up into the floor zone so the ceiling runs through level, which usually means more work to the joists. This needs deciding before the engineer designs the steel.
What happens at the survey visit in Mid and East Antrim?
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.