Removing internal and load-bearing walls to open up your rooms — with the steel beam calculated by our in-house structural engineers, supported on engineered padstones and signed off by Building Control. From a single partition to a double through-room, designed and built under one fixed-price contract, with the Party Wall process handled for you.
Joining two rooms into one is one of the most transformative changes you can make to a London house — and one of the most commonly botched. A knock-through looks simple: take out the wall, make good, decorate. But if the wall is load-bearing, what you are really doing is removing part of the structure that holds your house up and replacing it with a steel beam. Get that calculation, that beam and its supports right and you will never think about it again. Get it wrong and the consequences range from cracked ceilings to genuine danger.
This page is for doing it properly: removing internal and load-bearing walls, the knock-through, wall removal and structural alterations, engineered by qualified structural engineers and built by our own trades under one fixed-price contract. Whether you want to open up the whole ground floor or simply join two reception rooms, the structural discipline is the same.
The first question is always the same: is the wall load-bearing? Many builders will tell you on a glance. We do not guess — we survey, check the direction of the joists above and what the wall is carrying, and only then design the support. Where the wall is non-structural, removal is quick and inexpensive. Where it is load-bearing, we install a steel beam (an RSJ, in common parlance) sized to the span and load, supported on calculated padstones, with the structure temporarily propped while it goes in.
Every load-bearing knock-through requires Building Regulations approval, and where a shared wall is involved the Party Wall etc. Act applies. We handle the structural calculations, the steel, the Building Control submission and inspections, and the Party Wall notices — so the only thing you have to decide is whether the beam should be hidden flush or expressed. For the wider capability behind this work, see our structural works service.
From a quick partition removal to a full structural reconfiguration, the approach and the engineering differ. These are the six we handle most.
A stud or lightweight partition that carries nothing above comes out quickly, with making-good to floor, walls and ceiling and decoration to match. No beam, no Building Control structural approval — the fastest, cheapest way to join two spaces.
A structural wall removed and replaced with a calculated steel beam on padstones. The standard knock-through between two reception rooms or a kitchen and dining room. Engineered, propped, installed and signed off — the bread and butter of opening up.
Two openings — or a single very wide opening — creating a full through-room from front to back, the classic Victorian terrace transformation. Often uses paired or deeper beams, and careful sequencing to keep the structure supported throughout.
Removing the dividing wall and a chimney breast together to fully open a room. Both are structural, both need their own support and sign-off, and doing them in one programme is tidy and efficient. See our chimney breast removal page for that side in detail.
Where a full removal is not feasible or desirable, a wide opening retaining a pier or a section of wall — keeping a degree of separation and reducing the beam span. A neat broken-plan solution where the structure or budget favours it.
Several walls removed together to create a single open-plan ground floor — multiple beams, coordinated services and finishes. The largest version of a knock-through; our open-plan living page covers the layout, kitchen and zoning side.
A load-bearing wall removal is a sequence of carefully ordered structural steps. Every element below is delivered and warranted under one fixed-price agreement.
We establish exactly what the wall is doing — checking joist direction, the load path above and the foundation below, lifting a board if needed — so the design is based on fact, not assumption. The single most important step, and the one most often skipped.
Our MIStructE engineers size the steel beam to the span and the load it must carry, calculate the padstones it bears on, and check the supporting masonry. Full calculations issued for Building Control and kept on record.
Engineered propping and needling installed to carry the structure safely while the wall is removed and the beam is positioned — the part that keeps everyone safe and the house intact during the opening.
The universal beam (RSJ) lifted in, seated on its padstones, levelled and connected. Detailed to sit flush within the floor zone where the structure allows, or as a clean, boxed downstand where a deeper section is required.
Pre-cast concrete padstones to calculation spread the beam's load into the supporting walls, with the masonry checked and strengthened where required — the unglamorous detail that stops a beam punching into a wall over time.
The new opening squared and finished, the beam encased or detailed, the ceiling and walls re-plastered, and the junction between the two former rooms resolved cleanly — so the join reads as one room, not a patched-up gap.
Radiators, pipework, electrics, switches and sockets sitting on the removed wall are re-planned and re-routed cleanly into the new layout — coordination that stops the finished room being spoiled by an awkward radiator or socket.
Floor levels matched across the two former rooms and the finish run through — whether repairing existing boards or laying new — so there is no awkward threshold or level change where the wall used to be.
Full Building Regulations submission for the structural work, with the steel and bearings inspected before they are concealed and a completion certificate issued — the document that protects you and matters at resale.
Where the wall is shared with a neighbour or a beam bears into a party wall, notices served, schedules of condition prepared and the award agreed — all through our sister surveying company, so it is done correctly.
A full decoration of the joined space to a single finish, so the two former rooms read as one — not as a wall that used to be there, freshly painted on either side.
A two-stage snagging process, a 12-month defects period, a 10-year workmanship warranty and a free service visit at six months.
It is the question that decides everything — the cost, the method and the approvals. Here are the signs we check, and why a proper survey is the only certain answer.
If the floor joists above run at right angles into the wall, the wall is very likely carrying them. We lift a board above to confirm direction and span — the most reliable single check.
A wall that lines up with a wall on the floor above, and continues to the roof, is usually structural — it is part of a load path running down through the house to the foundations.
The central spine wall running front-to-back through a terrace is almost always load-bearing, carrying floor joists on both sides. These are the walls most people most want to remove.
Solid masonry walls are more likely to be structural than thin stud partitions — but thickness alone is not proof, which is why a visual guess from a builder is never enough to design on.
A wall beneath a bath, a water tank, a heavy stud wall or a chimney is likely carrying concentrated load. We trace exactly what bears on the wall before specifying the beam.
Clues point the way, but the only reliable answer is a structural inspection. We survey before we price, so the design and the cost are based on what is actually there.
Even a single wall removal benefits from a disciplined sequence. Here is how we run it.
We look at the wall (or walls) you want gone, discuss how you want the rooms to work, and talk realistic budgets. No charge, no obligation.
A structural survey establishing what each wall carries, the joist direction and the load path — the basis for an honest design and a firm price.
The opening designed, the beam detail (flush or downstand) resolved and shown to you, and the impact on services and finishes mapped out before you commit.
Beam and padstone calculations produced by our MIStructE engineers, ready for Building Control submission.
Building Regulations submission and, where a shared wall is affected, Party Wall notices served and the award agreed.
Temporary propping installed, the wall removed, the beam lifted in and seated, props struck, opening made good. Building Control inspects the steel and bearings.
Plastering, services re-routing, flooring continuity and decoration to a single finish, then a snagging walk and the completion certificate.
A 12-month defects rectification period, a six-month service visit and a 10-year workmanship warranty.
A knock-through can be a quick opening or a beautifully detailed one. Here is how our four tiers differ.
For a representative single load-bearing knock-through at around £13,000, here is the honest breakdown of where every pound is spent.
A knock-through is structural engineering first and decorating second. Here is what is calculated and installed.
A knock-through is almost never a planning matter — but it is always a Building Regulations one if the wall is load-bearing.
Removing an internal wall does not require planning permission in an unlisted house — you are not touching the exterior or the footprint. What it does require, whenever the wall is load-bearing, is Building Regulations approval. The structural design must be calculated, submitted, and the steel and bearings inspected before they are hidden, with a completion certificate issued at the end. That certificate is not red tape — it is what protects you, satisfies your insurer and reassures a future buyer's surveyor.
Where the wall is a party wall — shared with an attached neighbour — or where a new beam will bear into it, the Party Wall etc. Act 1996 applies. Notice must be served on the affected neighbour, a schedule of condition prepared, and an award agreed before work starts. We manage this through our sister surveying company, so it is done correctly rather than discovered too late.
The only time planning enters the picture is if the project also involves a Listed building (where internal alterations need Listed Building Consent) or an extension of the footprint. We confirm exactly what your knock-through needs at survey and manage every approval for you. For an early budget, use the cost calculator; if you are opening up the whole floor, see open-plan living.
A representative programme for a single load-bearing wall removal with a steel beam. Yours will differ by scope, but this is what a properly run knock-through looks like in real time.
Plenty of builders will take a wall out. Here is what makes ours safe, clean and worth the difference.
Our own MIStructE engineers calculate the beam — the design and the build sit under one roof, not split between a separate consultant and a builder guessing.
We confirm whether a wall is load-bearing by inspection before we price — never by a glance, which is how dangerous shortcuts happen.
One agreement covering survey, design, steel, approvals and finishes. No cost-plus surprises once the wall is open.
We design steel to sit flush wherever the structure allows — no clumsy unplanned downstand cutting across the ceiling.
Submission, inspection and completion certificate managed for you — the paperwork that protects you at resale.
RICS surveying support for the Party Wall process where a shared wall is involved.
Professional indemnity and public liability at £10M, well above industry standard.
An insurance-backed workmanship warranty protecting the structural work long after completion.
A knock-through often sits within a wider project. Start here, or speak to us about combining it under one contract.
Opening up the whole ground floor — the layout, kitchen and zoning side of multiple knock-throughs.
Often done alongside a knock-through — structural removal on gallows brackets or steel.
The full structural capability — beams, openings, underpinning and floor strengthening.
The calculations and detailing behind every beam and opening, by MIStructE engineers.
Joining the kitchen to the living space is a common reason to knock through — designed together.
Combining a knock-through with a side-return for the widest possible rear space.
Wall removal as part of a wider whole-house renovation, delivered as one programme.
The notices and awards required where a knock-through affects a shared wall.
Comparable projects with real structural openings and finishing standards. Browse the case-study hub, and for survey-led due diligence before you commit, see surveying support.
Load-bearing walls removed on engineered steel to create a single open-plan ground floor.
View case study →Structural opening and rear extension joining the kitchen to the living space.
View case study →Structural reconfiguration and multiple openings within a full townhouse renovation.
View case study →Browse the full portfolio of openings, extensions and renovations across prime London.
View portfolio →“I would like to thank Ross and his team for their consistent commitment to quality and their unerring reliability. They delivered our property to specification and on time, proving to be an extremely effective, experienced, and proactive contractor.”
“We have worked with Ross and his company many times. They are extremely professional and hardworking individuals who can work under any circumstances. There was no variation to the works.”
Book a no-obligation consultation at our Finchley Road design studio or in your home. The first meeting is free, lasts 60–90 minutes, and concludes with an honest indication of feasibility, programme and budget band. No salespeople. No pressure.
Site visit · feasibility assessment · outline cost estimate · programme indication. No obligation. Saturday appointments available.