Through-lounge knock-throughs · Streatham
Through-lounge knock-throughs in Streatham
Through-lounge knock-throughs for homes in CR4, SE21, SE27, designed by a structural engineer.
- Survey, design and installation in one
- Covering CR4, SE21, SE27
- Inspected before it is covered
- Free survey visit
- Engineer's calculations arranged
- Building control handled
- Fixed written price once scope is agreed
- England, Wales, mainland Scotland & NI
What through-lounge knock-throughs involve in Streatham
Through-lounge knock-throughs in Streatham are planned around the house, not a standard kit. Our coverage runs across London, so nearby villages are included too. We visit, measure and check what the wall carries, then arrange calculations and building control approval before any steel is ordered.
Many period terraces and semis were built with a front parlour and a back sitting room divided by a solid brick wall. Opening them into one through-lounge brings light from both ends of the house, but that wall commonly carries the floor joists, the wall between the bedrooms above and sometimes part of the roof load too.
What to expect
- With the wall gone, the floorboards on each side may run in different directions or sit at slightly different heights. Matching reclaimed boards can be fitted across the old wall line, or the floor can be levelled for a new continuous finish.
- The width of the opening, whether the beam bears into a party wall, and how much period detail has to be restored all affect the price. Lath and plaster repairs, cornice matching and floorboard work are priced as separate lines in the quote.
- The structural stage for a through-lounge typically takes three to five working days. Both reception rooms are out of use for that time, so furniture is moved out or stacked and sheeted, and the hallway is kept clear as the main walkway.
- Minor hairline cracks can appear in plaster upstairs as the structure takes up the new support. This is common after a knock-through and is usually filled at decoration stage, but wider or growing cracks should be reported so they can be checked.
- Radiators, pipe runs and sockets on the dividing wall need relocating. Older houses sometimes have heating pipes running under the floor along the wall line, so these are traced and moved by a heating engineer before the wall comes down.
Four stages, one team
Survey in Streatham
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.
How much should I budget in Streatham?
As a guide, budget £3,200–£7,050 including VAT for through-lounge knock-through in Streatham, based on published UK cost guides adjusted for London prices (+28%).
| Job | Typical guide range | What it usually covers |
|---|---|---|
| Through-lounge knock-through | £3,200–£7,050 | Wall between front and back reception rooms, steel beam, approvals, plastering and floor infill |
| Chimney breast removal (ground floor) | £1,900–£3,850 | Ground-floor breast removed, steel to support the breast above, building control and making good |
| Plastering and making good | £380–£1,540 | Boxing the beam, bead and skim, reveals, floor infill where the wall stood and tidy-up |
| 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 |
Figures include our approximate regional adjustment for London prices (+28%) and are rounded. How these figures are worked out.
Approvals in Streatham
For Streatham, 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.
Through-lounge knock-throughs in Streatham: your questions
How much do through-lounge knock-throughs cost in Streatham?
As a guide, budget £3,200–£7,050 including VAT for through-lounge knock-through in Streatham, based on published UK cost guides adjusted for London prices (+28%). The exact figure depends on the span, what the wall carries, access and the finish, and is fixed in writing once the scope is agreed.
Do you cover Streatham for through-lounge knock-throughs?
Yes. We carry out through-lounge knock-throughs in Streatham and the CR4, SE21, SE27, SW2 and SW4 postcode districts. Book a free survey visit and we will check the wall, arrange the engineer's calculations and send an itemised written quote.
How long does a through-lounge knock-through take?
The structural part usually takes three to five working days, covering needling, propping, removing the wall, fitting the steel and packing it. Party wall notice periods, plastering, period repairs and drying time sit around that, so the overall timeline depends mostly on notices and the finishing work.
Do I need consent to knock through in a listed building?
Yes, you need both listed building consent and building regulations approval. Listed building consent from the local planning authority covers internal structural changes to the building's fabric, and building control covers the structural safety. Carrying out works to a listed building without consent is an offence, so it must be in place before anything is booked.
Do I need a party wall agreement for a through-lounge?
In England and Wales, yes, if the beam end will be cut into the wall shared with your neighbour: a party structure notice must be served at least two months before that work. Your neighbour can consent or dissent. Scotland and Northern Ireland have no Party Wall Act, so title deeds and the general law apply instead.