RSJ and Steel Beam Installation Windsor

Once a wall is removed from a Windsor home, its load passes to a steel beam known as an RSJ. Around that beam we cover surveying, temporary propping, padstones, making good and the inspections needed for sign off. A structural engineer appointed by us supplies the calculations, and our installation follows them. We never produce those calculations ourselves. This page sets out what an RSJ job on a Windsor property involves, and who checks it.

For Windsor, on London-derived ranges a steel beam for one opening typically costs £1,500 to £4,000 fitted and signed off, or £2,500 to £6,500 or more for a full knock-through with the engineer's fee and making good; Berkshire work generally runs below that. GS Renovation Ltd, a building contractor based in Potters Bar, does the work in Windsor.

How the job runs

1. Free site survey at your Windsor address and an itemised quote.
2. The engineer we appoint sizes the beam, and the work is registered with Royal Borough of Windsor and Maidenhead building control or an approved inspector. On a shared wall you serve the party wall notice as building owner; we supply the drawings.
3. Props go in, the opening is cut and the beam is set on padstones, packed tight above.
4. Building control inspects the steel before it is covered. We make good, and the completion certificate follows.

Windsor building control books your steel in for its own inspection before it is encased

Steel beams and columns get their own inspection stage with the Royal Borough of Windsor and Maidenhead, held before encasement and booked on one day's notice. That is the point at which the beam, its bearings and its padstones can still be seen. Once the steel is boxed in and plastered, that opportunity has gone. We hold the programme so the inspection happens while the work is still open.

The council's other notice periods sit around it. The council wants two days' notice ahead of starting, one day's notice for foundation excavations and again for steel beams before encasing, and seven days' notice ahead of occupation. We make the building control application and book each of those dates against our own programme, so the trades that follow are not waiting on a visit nobody arranged.

Housing in Windsor

Windsor's housing, as the Council Tax list records it, is about 16,960 homes: 66% houses, 34% flats, with 22% pre-1919, 8% interwar and 68% built since 1945. 30% of homes here are terraced; a beam in a terrace in Windsor often bears on the party wall, bringing in the Party Wall Act.

What the Royal Borough charges to sign off a single beam

Charge category C3 in the council's building control schedule applies to structural alterations of a single beam or chimney breast removal. Including VAT, the fee from 1 April 2026 is £300.00 via a full plans application and £345.00 via a building notice. Those are the council's figures, not ours, and they sit alongside the build cost rather than inside it. You know our intended route before accepting any quotation.

Three storey houses with cellars change where the beam has to land

Everything above a steel beam ends up on two small bearing points, and each of those must carry it all the way down. On major streets like Clarence Road, Frances Road and Kings Road, the Inner Windsor appraisal from the council records three storey dwellings with cellars. Where a cellar sits beneath a bearing, the load path continues below the ground floor. Before any steel is ordered, we expose the bearing position, note what we find and send that to the engineer.

Getting a steel into a narrow fronted terrace needs a route, not just a lorry

Steel comes by lorry and goes in by hand, which is why we price access instead of assuming it. Minor side streets, in the council's Inner Windsor appraisal, are two storey terraces with narrow frontages. Reaching the rear, it records, means going through the dwelling, along a rear alleyway, or via passageways between individual properties.

At Gardner Cottages the pattern is set out in the building itself. In every twelve cottage terrace, larger cottages close both ends, and a larger pair stands in the middle either side of a passage to the rear. Whether the beam comes through the front door or round the back changes the length that can be handled and the propping sequence. We measure both routes at survey and agree the delivery point with you.

• Goalpost frames where two walls meet at a corner
• Beam boxing, fire protection and plasterboard encasement
• Structural openings for open-plan living

VOA Council Tax stock of properties, March 2025, for all 5 statistical areas in Windsor. Counts rounded by the VOA.

When comparing RSJ and steel beam installation in Windsor with other work, it helps to read home renovation in Windsor, RSJ and steel beam installation in Slough, building control sign-off for a steel beam, the Party Wall Act when a beam bears on a shared wall, how we handle RSJ and steel beam installation across London and Lintel Replacement Cost.

The GS Renovation Difference in Windsor

Engineering is not our practice; contracting is. On a Windsor beam, the structural engineer is ours to appoint, their calculations set what we install, and propping stays in place until the steel bears as it should. The building control application goes to the Royal Borough of Windsor and Maidenhead, and we make it and book the pre-encasement inspection around our own programme rather than after the fact. You deal with a single contact for the engineer, steel, brickwork and sign off. We are fully insured.

Checked by Abdelaaziz Saaid, founder and director of GS Renovation Ltd (Companies House no. 14611254). Structural design is by the consulting engineer appointed to your project.