Steel BeamInstallers
Victorian through-lounge with a boxed beam where the dividing wall used to be

Through-lounge knock-throughs · Blackwood

Through-lounge knock-throughs in Blackwood

Through-lounge knock-throughs in Blackwood, from free survey to completion certificate.

  • Survey, design and installation in one
  • Covering CF81, CF82, NP12
  • Inspected before it is covered

Free survey in Blackwood

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  • Free survey visit
  • Engineer's calculations arranged
  • Building control handled
  • Fixed written price once scope is agreed
  • England, Wales, mainland Scotland & NI

Through-lounge knock-throughs in Blackwood: how it works

We cover through-lounge knock-throughs in Blackwood (CF81, CF82, NP12) and the streets around it. Our coverage runs across Caerphilly, so nearby villages are included too. Each job is designed by a structural engineer and approved through Caerphilly County Borough Council before work begins.

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.

Things to plan for

  • 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.
  • 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.
  • Ornate cornicing often runs around both rooms and stops at the wall being removed. Where practical, the run is extended across the opening by matching the profile, either run in place or cast, so the joined room looks original rather than patched.
  • In most terraced houses the wall between the front and back rooms runs across the house and carries the floor above, plus the wall between the front and back bedrooms. It is normally load-bearing, but the engineer still checks before any design is drawn up.
  • Period ceilings are often lath and plaster, which can crack or sag when the wall below is disturbed. Props are set to spread load gently, and damaged areas are repaired with lime plaster or overboarded, depending on the condition and your preference.

How the job runs in Blackwood

  1. Look and measure

    We check the wall, the span you want and what the wall is carrying, and photograph anything the engineer needs to see.

  2. Design and price

    Calculations come back from the engineer and we confirm your fixed written price, line by line.

  3. Building control

    We submit the application or notice to Caerphilly County Borough Council under the Building Regulations as they apply in Wales, before work starts.

  4. Fit, inspect, finish

    The work is propped and the steel installed and packed tight. After inspection the opening is boxed, plastered and left clean.

How much should I budget in Blackwood?

As a guide, budget £2,300–£5,000 including VAT for through-lounge knock-through in Blackwood, based on published UK cost guides adjusted for prices in Wales (-9%).

JobTypical guide rangeWhat it usually covers
Through-lounge knock-through£2,300–£5,000Wall between front and back reception rooms, steel beam, approvals, plastering and floor infill
Load-bearing wall removal with steel beam£1,800–£4,550Typical internal wall up to about 4 m: calculations, building control, propping, steel, padstones, fitting, fire protection and making good
Plastering and making good£270–£1,090Boxing the beam, bead and skim, reveals, floor infill where the wall stood and tidy-up
Kitchen-diner knock-through£2,300–£5,450Internal structural wall between kitchen and dining room, steel beam, approvals and making good (kitchen fitting extra)

Figures include our approximate regional adjustment for prices in Wales (-9%) and are rounded. How these figures are worked out.

Approvals in Blackwood

In Wales, structural alterations come under the Building Regulations 2010 as they apply in Wales. Caerphilly County Borough Council handles building control for Blackwood. For work started or approved from 1 July 2026, the Welsh system uses an application to building control, dutyholders appointed in writing, a commencement notice before work starts and a compliance statement at the end.

The Party Wall etc. Act 1996 applies in Wales as well as England, so a beam bearing into a shared wall needs a party structure notice at least two months before work starts. We arrange notices through a party wall surveyor.

Building rules in Wales

Through-lounge knock-throughs near Blackwood

Through-lounge knock-throughs in Blackwood: your questions

How much do through-lounge knock-throughs cost in Blackwood?

As a guide, budget £2,300–£5,000 including VAT for through-lounge knock-through in Blackwood, based on published UK cost guides adjusted for prices in Wales (-9%). 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 also work near Blackwood?

Yes. We also cover nearby towns including Gelligaer, Risca, Pontypridd and Pontypool.

Is the wall between two reception rooms load-bearing?

In most period terraces and semis it is, because it carries the floor joists and the wall between the bedrooms above. Some later houses have lighter partitions in this position, so the only way to be sure is an engineer's inspection. We arrange this during the survey and design stage.

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.

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.

Planning to take a wall out?

Book a free survey visit. You get an itemised written quote covering calculations, building control, steel and making good.