Removing a load-bearing wall in London: steel beams and RSJ installation

London cost guides put a single opening with one steel beam at £2,500–£5,000 all in, engineer's calculation, RSJ and building control included, and a through-lounge or a full open-plan ground floor with several beams at £5,000–£15,000. The steel is a small part of either figure; the propping, the labour and the making good are the cost. Add party wall fees where the beam bears into a shared wall. Market ranges from September 2026, not our quotes.

London guides quote an RSJ supplied and fitted at £1,500–£5,000 per beam. The steel itself is usually a few hundred pounds (one UK guide puts a three-to-five-metre beam at £250–£600 and a large or heavily loaded one at £600–£1,200 or more); the rest is the temporary works, the padstones, the labour to lift and bed it, the dry-packing and the plasterboard casing. Longer spans, a two-storey wall, a beam split and spliced to get into a terrace, and a goalpost frame on new foundations all push a beam towards the top.

Yes. Removing an internal wall or forming an opening in one is controlled by the Building Regulations whether the wall is load-bearing or not, and a new beam has to have proper bearings and fire protection. Building control hears about the work before it starts, sees the beam before it is boxed in and signs it off with a completion certificate. The London boroughs that publish a clear schedule charge £360–£515 including VAT for a structural opening. When you sell, that certificate is the first thing the buyer's solicitor asks for.

Yes, for anything load-bearing. The engineer confirms what the wall carries, sizes the beam for the load and the span, checks deflection and specifies the padstones; building control then inspects against that calculation. In London a single beam with a site visit is charged at £450–£800, more for several beams or a goalpost frame. We include the engineer's design, so the person who sized the beam and the crew who fit it answer to one contract.

Treat it as structural until proved otherwise. A wall the floor joists run into rather than past, a wall that continues on the floor above, a spine wall down the middle of a terrace, a wall thicker than a stud partition and any wall carrying a chimney breast or a purlin should all be assumed to be load-bearing. A wall that sounds hollow is not automatically safe to remove, because stud walls sometimes carry ceiling joists. The only reliable answer is to open a small area and trace the load path.

Padstones: blocks of dense concrete or engineering brick built into the wall at each end of the beam, which spread the concentrated load from the steel into the brickwork below so it does not crush. The Planning Portal's guidance says a beam should normally have at least 150 mm of bearing on each side, and the engineer sizes the padstones for the load. Where there is nothing solid to bear on, for example an opening that runs to the outside wall, the beam sits on a steel post instead, forming a goalpost frame down to a foundation.

All of it, if the design allows for it. Leaving a nib of wall at each end gives the beam something to bear on and keeps the cost in the single-opening bracket; removing the wall from face to face means posts at each end, a goalpost frame and usually new foundations under the posts, which is the £5,000–£15,000 case in the published London figures. The limit is not the wall but what the floor above, the walls above and the foundations below can be made to accept, which is the engineer's question rather than the builder's.

There is no lookup table that is safe to use. The section depends on the load the beam carries, which is different for a wall supporting one floor, two floors or a roof, on the span, on how much deflection the floor above can tolerate and on what the bearings can take. Two six-metre openings in the same street can need different beams. The engineer works it out from the survey, and a beam ordered from a guess is the reason floors bounce and ceilings crack.

Steel is priced by weight, so a longer or heavier section costs more, but the beam is still the smaller part of the job: London guides put a beam supplied and fitted at £1,500–£5,000, with the steel usually a few hundred pounds of that (£150–£1,200 in one UK guide, by size). What a long beam adds is logistics. A seven-metre length rarely gets down a terrace hallway, so it arrives in two pieces with an engineer-designed bolted splice, and needs more props, more hands and a heavier goalpost frame if it has no wall to bear on.

Yes. Section 2 of the Party Wall etc. Act 1996 gives a building owner the right to cut into a party structure to take the bearing of a beam, provided a party structure notice is served no less than two months before the work begins. On a mid-terrace with a beam spanning wall to wall that means both neighbours. Written consent within 14 days is the agreement; otherwise an award is drawn up, and published London figures put an agreed surveyor at £700–£1,800 per neighbour, more where each side appoints their own.