RSJ and Steel Beam Installation Lambeth

GS Renovation installs RSJs and steel beams across Lambeth, from the Georgian townhouses of Kennington to the Victorian terraces around Clapham Common. We open up period homes safely, with beams sized by a structural engineer and signed off by building control.

In Lambeth, 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 Lambeth.

How the job runs

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

Steel beams for Lambeth period homes

Lambeth's Georgian, Regency and Victorian houses were built with solid brick walls and internal load-bearing partitions, so removing a wall to create flow means transferring real weight onto a new steel. In SW2 and SE24 the structural engineer sizes the RSJ; we cast or supply padstones at each bearing, and install temporary propping before any masonry comes down. Every stage is planned so the structure above stays supported throughout.

Because many Lambeth homes sit within conservation areas or carry listed status, we keep steelwork discreet, dropping beams into the ceiling line where head height allows and boxing them cleanly afterwards. We stage demolition carefully in occupied houses around Brixton and Streatham, protecting original cornicing and floors. Once the beam is bearing correctly on its padstones, building control inspects the work before we close everything up.

Housing in Lambeth

Of the 148,600 homes the valuation list records in Lambeth, 40% were built before 1919, 14% between the wars and 46% since 1945; 77% are flats and 23% are houses. Where most homes are flats, a beam in a leasehold flat in Lambeth needs the freeholder's licence for alterations, since the lease usually keeps the structure with the freeholder.

Choosing the Lambeth building control route before the steel is ordered

Lambeth gives you two ways to get building regulations approval for work at home: a building notice or a full plans application. For a steel beam that choice sets the programme. Lambeth says a building notice is the quicker of the two, and works can commence 48 hours after it receives one. That speed suits a simple opening where the structural engineer we appoint has already finished the calculations. What it does not give you is an approved drawing before the wall comes out. The inspector judges the beam, the bearings and the padstones against those calculations on site, and nothing is closed in until that visit is recorded.

A full plans application is slower but settles the design on paper first. Lambeth recommends submitting it at least five weeks before you plan to start on site, and within three working days of receiving either kind of application its building control team sends a letter confirming whether it can process it. On a Lambeth job we treat that letter, not the day the drawings were finished, as the point at which steel is ordered. A beam made to a design that is later queried is an expensive length of scrap, so for a long span or an awkward bearing on old brickwork we suggest full plans.

Party wall steelwork across Lambeth terraces

A large share of Lambeth's terraces and semis share a party wall with the neighbouring house, and chimney breasts and dividing walls often sit right on that boundary. Where your beam bears into a shared wall, the Party Wall Act applies, so you serve the correct notices on adjoining owners in good time. This keeps SW8 and SE27 projects lawful and avoids disputes once the drilling and cutting begin.

We handle the practical side too, from propping the floors above to protecting the neighbour's side of the wall during breaking out. Our teams work to a sequence agreed with building control, so inspections happen at the right moments and nothing is hidden. Whether you are removing a chimney breast in Vauxhall or a spine wall in Clapham, the steel is specified by the engineer, installed by us and signed off by building control to keep your home sound for decades.

Needles, props and holding the house up

The temporary works are the part of a steel installation that keeps everyone safe, and they are designed rather than improvised. Where the wall carries a floor and a wall above, we cut needles, short beams passed through holes in the masonry above the line of the new opening, and prop them from below on both sides. That takes the load off the wall before a single brick is removed.

Props have to stand on something solid. On a suspended timber ground floor in a Lambeth terrace that means spreader plates across the joists, or taking the props down to a solid base below. The propping stays until the beam is seated and packed tight to the masonry above and the padstones have gained strength. Striking props early is one of the few genuine ways to cause damage on this kind of job, so it happens in order rather than to suit a diary.

• Load-bearing wall removal and knock-throughs
• Beam boxing, fire protection and plasterboard encasement
• Concrete and high-density padstones at every bearing

VOA Council Tax stock of properties, March 2025, for all 35 statistical areas in Lambeth. Counts rounded by the VOA.

Two or three things usually come up alongside RSJ and steel beam installation on a Lambeth job: home renovation in Lambeth, our Lambeth area guide, building control sign-off for a steel beam, the Party Wall Act when a beam bears on a shared wall, RSJ and steel beam installation anywhere in London and Knock-Through Guide.

Why Choose GS Renovation in Lambeth

Homeowners across Lambeth trust GS Renovation because we treat structural work as the serious job it is. One team coordinates the engineer's design, the propping and the building control sign-off, working tidily in occupied period homes. With our founder's 30+ years on the tools, we deliver steelwork that is safe, signed off and built to last.

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.