
Flat & HMO conversion steels · London
Flat & HMO conversion steels in London
Survey, engineer's design and installation of flat & HMO conversion steels anywhere in London.
- Free survey visit in London
- Engineer's calculations arranged
- Building control handled for you
- Free survey visit
- Engineer's calculations arranged
- Building control handled
- Fixed written price once scope is agreed
- England, Wales, mainland Scotland & NI
What flat & HMO conversion steels involve in London
Flat and HMO conversion steels are the beams, columns and frames needed when a house or building is reworked into self-contained flats or a house in multiple occupation. New layouts move walls, stairs and bathrooms, so steel picks up the loads that old walls used to carry, designed to work alongside the fire separation and sound insulation the conversion also needs.
From the first survey visit to the completion certificate, we take care of flat & HMO conversion steels across London. That includes Westminster, Barking and Islington, plus smaller towns and villages nearby. The engineer sizes the steel, we deal with building control, and our team fits and packs the beam before making good.
Things to plan for
- The engineer looks at the whole building rather than one opening at a time. Loads from upper floors, new bathrooms and water storage are traced down to the foundations, and steel is placed so it suits the new layout without awkward downstands in habitable rooms.
- Keep the structural calculations, building control completion certificate and fire protection records together in one place. They are needed for signing off the conversion, and buyers, lenders and licensing officers may ask to see them later.
- A conversion to flats or an HMO may need planning permission for the change of use, depending on the scheme, its size and any local restrictions. Checking the planning position before design work begins avoids redesigning the layout and its steel later.
- Converting a house into flats is treated as a material change of use for building regulations purposes, so fire safety, sound insulation and other requirements apply across the building, not just to the structural work. The steelwork forms one part of that wider approval.
- The reduced 5% rate of VAT may apply to some conversion work, such as changing the number of dwellings in a building. Whether it applies depends on the details of the scheme, so confirm the position with your accountant before relying on it.
From survey to sign-off in London
Survey in London
We visit, look at the wall and what sits above it, measure the opening and note services, access and how the steel can be brought in.
Engineer's design
A structural engineer sizes the beam, padstones and any posts, and sets out the temporary support needed while the wall is out.
Building control
We submit a building notice or full plans application to the local council's building control team, so approval is in place before the wall is touched.
Install and sign-off
Props go in, the opening is formed, the steel is set and packed, building control inspects it, and we make good.
Guide prices for flat & HMO conversion steels in London
As a guide, budget £3,200–£11,500 including VAT for steelwork for a flat or HMO conversion in London, based on published UK cost guides adjusted for London prices (+28%).
| Job | Typical guide range | What it usually covers |
|---|---|---|
| Steelwork for a flat or HMO conversion | £3,200–£11,500 | Beams and posts for a revised layout, with approvals; fire and sound separation priced with the conversion |
| Load-bearing wall removal with steel beam | £2,550–£6,400 | Typical internal wall up to about 4 m: calculations, building control, propping, steel, padstones, fitting, fire protection and making good |
| Structural calculations for a beam | £320–£960 | Site measure or photos, beam and padstone design and calculations for building control |
| Building control fees | £320–£830 | Building notice or full plans fee and inspections; varies by council or approver |
Figures include our approximate regional adjustment for London prices (+28%) and are rounded. How these figures are worked out.
Building rules for London
For London, building control is provided by the local council's building control team, or by a registered building control approver if preferred. We send them the engineer's calculations with a building notice or full plans application and book the inspections. Work done without approval can cause problems at sale and is far dearer to put right later.
Terraced and semi-detached homes often need party wall notices, because cutting into a shared wall to take a beam end is notifiable under the Party Wall etc. Act 1996. Allow at least two months for the notice period unless your neighbour agrees sooner.
Flat & HMO conversion steels by town
- Brent
- Islington
- Westminster
- Bexley
- Barking
- Archway
- Sutton
- Croydon
- Ilford
- Enfield Town
- Harrow
- Tottenham
- Walthamstow
- Dagenham
- Becontree
- Romford
- Hayes
- Wembley
- Fulham
- Edmonton
- Southall
- Putney
- Battersea
- Purley
- Peckham
- Chingford
- Uxbridge
- Wimbledon
- Stamford Hill
- Brixton
- Hounslow
- Finchley
- Cricklewood
- Mitcham
- Feltham
- Acton
- Beckenham
- Chelsea
- Streatham
- South Croydon
Questions about flat & HMO conversion steels in London
Who approves flat & HMO conversion steels in London?
Structural work in London needs a building notice or full plans application to the local council's building control team or a registered building control approver. We prepare and submit it with the structural engineer's calculations and arrange the inspections, so the completion paperwork follows the job.
Can you work on older or listed homes in London?
Yes. Older homes often have lime mortar, timber lintels or shallow footings, which the engineer allows for. Listed buildings need listed building consent for internal structural changes as well as building regulations approval, and that must be in place first.
How is sound insulation handled around steel beams in flats?
Through careful detailing. Separating floors and walls between flats must meet sound insulation standards, so steel connections, boxing and packing are designed not to leave gaps or create direct paths for noise. In England and Wales, sound testing is normally carried out on conversions before completion to show the separating construction performs.
Does 5% VAT apply to a flat conversion?
It may. A reduced rate of VAT can apply to some conversion work, such as changing the number of dwellings in a building or converting a house into an HMO, provided the conditions are met. The rules have detail and exceptions, so confirm the position with your accountant before pricing the project on that basis.
How long does the steelwork take on a house-to-flats conversion?
Typically one to three weeks on site, depending on how many walls move and how the work is phased. The steel is usually among the first structural stages, so it is programmed early to let partitions, services and fire separation follow. The full conversion takes considerably longer than the steelwork alone.
What steel beams are needed for a flat conversion?
It depends on how much the layout changes. Typical steelwork includes beams where load-bearing walls are removed, trimmers around new stair openings, and columns or frames where loads have to come down through the building. A structural engineer designs each element from the new layout and the existing structure, and the calculations go to building control.