RSJ and Steel Beam Installation Soho

GS Renovation installs RSJs and structural steel across Soho and the wider W1 postcode, working in the characterful period buildings and upper-floor apartments that define the area. We prop and set every beam to the engineer's sizing correctly, from knock-throughs inside upper-floor flats to openings in buildings with a shop at street level.

In Soho, 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 (indicative London ranges, MyBuilder and Checkatrade, 2026). GS Renovation Ltd, a building contractor based in Potters Bar, does the work in Soho.

How the job runs

1. Free site survey at your Soho address and an itemised quote.
2. The engineer we appoint sizes the beam, and the work is registered with Westminster City Council 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.

Removing load-bearing walls in Soho flats

Most steel work in Soho happens inside upper-floor flats, taking out the wall between a front room and a back room or kitchen to create one bright, connected space. The structural engineer we appoint calculates the beam size and the padstones it bears onto, then we install temporary props, carry out safe staged demolition and lift the RSJ into position. Every stage is inspected and signed off by Westminster building control.

Because dividing walls and chimney stacks in these W1 buildings usually sit within a shared party wall, the work often triggers the Party Wall Act. We flag this early, so you can serve the correct notices on neighbours before demolition begins. Most Soho homes are upper-floor flats, often above other flats or a shop, which means propping and access have to be planned carefully around occupied rooms and narrow period staircases.

Housing in Soho

The Fitzrovia West & Soho statistical area's housing, as the Council Tax list records it, is about 6,840 homes: 2% houses, 98% flats, with 48% pre-1919, 5% interwar and 47% built since 1945. A beam in a leasehold flat in Soho needs the freeholder's licence for alterations, since the lease usually keeps the structure with the freeholder, which matters here because most homes are flats.

Old brick or post-war frame: dating a Soho building before steel

In Soho 48% of homes were built before 1919 and 47% after 1945, so the building your flat sits in is close to an even chance of being either. That decides what an RSJ is even for. In a pre-1919 building the walls carry the floors, and a beam replaces masonry that was doing real work. In a post-war building the load may run through a concrete or steel frame, an internal wall may carry nothing, and a new opening may need no steel at all. The first question the structural engineer we appoint asks is the date and form of the building, before any beam is sized.

Westminster's building control schedule has a minor works category for new openings in a structural wall, in one property with fewer than 5 openings. In a Soho flat that can cover the whole scheme, and it pays to confirm the count before applying, because a second opening added later means going back to building control. If Westminster is your building control body, it must also be told the start date at least 2 days before work starts. We give that notice before the first prop goes in, and book the inspection of the bearings to fall between the steel going in and the ceiling going up.

Structural steel for Soho knock-throughs

Steel is not just for ground-floor rooms. In Soho we install beams for chimney breast removals, openings between flats being combined, and the occasional rear or roof alteration where the freeholder and Westminster allow it. Taking out a breast on one floor leaves the stack above needing support, now usually a steel beam, with gallows brackets only where the engineer and building control accept them. Each situation is different, so nothing goes in without engineer's calculations. We match the steel to the exact load, whether that is a single lintel or a heavy multi-span beam.

Once the beam is set on its padstones and the props come out, we make good the surrounding structure, fireproof the steel to regulations, and building control issues the completion certificate you will need when you sell. Working in central W1, we keep dust down, protect original cornicing and floors, and coordinate deliveries around the tight streets and parking restrictions that come with Westminster addresses so the job runs smoothly.

• Goalpost frames where two walls meet at a corner
• Party wall process explained, and the beam built to the award
• Load-bearing wall removal and knock-throughs

VOA Council Tax stock of properties, March 2025, for the Fitzrovia West & Soho statistical area, which also covers west Fitzrovia. Counts rounded by the VOA.

Once you know the scope of the RSJ and steel beam installation in Soho, it helps to read home renovation in Soho, RSJ and steel beam installation across Westminster, 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 Cracks in Walls: When to Worry.

Why Choose GS Renovation in Soho

Homeowners in Soho choose GS Renovation because steel is our core work, not a sideline. One team manages the engineer, the props, the demolition and the building control sign-off, so nothing falls between trades. With our founder's 30+ years on the tools, we install beams safely in occupied, characterful period homes.

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.