You’ve decided to open up your ground floor — maybe knock the kitchen into the dining room, or create that open-plan living space you’ve been planning for years. Before anyone picks up a sledgehammer, there are a few things you genuinely need to understand first, and getting them right will save you time, money, and a very uncomfortable conversation with Building Control.
Key Takeaways
- Not every internal wall is load-bearing, but assuming it isn’t can have serious structural consequences — a proper assessment is always worth it.
- A structural engineer’s beam calculations must come before the builder starts, not after something goes wrong.
- Building Regulations approval under Part A (Structure) is a legal requirement for this type of work — not optional.
- Temporary propping during the knock-through is just as important as the permanent steel beam.
- If the wall is on a boundary with a neighbour, the Party Wall Act may also apply.
Is the Wall Actually Load-Bearing?
This is the first question every homeowner asks, and it’s a fair one. The honest answer is: you can’t tell just by looking at it, and neither can most builders. There are clues — a wall running at right angles to the floor joists, sitting on a foundation or a beam below, with another wall or roof structure sitting above it — but clues are not conclusions.
I’ve visited properties where a wall looked like a simple partition but was actually carrying the full weight of a bedroom floor above, plus a section of roof. I’ve also seen walls that looked substantial but turned out to be non-structural stud partitions added during a 1970s refurbishment. The difference between those two scenarios, from a structural point of view, is enormous.
A proper assessment means looking at the original construction of the house, checking what sits above and below the wall, understanding how the floor joists span, and — where possible — inspecting the loft space to see how the roof loads are distributed. That’s what a structural engineer does. A builder’s “quick look” is not a substitute for that analysis, and if something goes wrong, Building Control will want to know who signed off the structural design.
What the Wall Might Be Carrying
Load-bearing walls in a typical UK terraced or semi-detached house can be carrying several things at once. Floor joists from the room above may be bearing directly onto the wall’s head. A wall on the first floor may be sitting directly above the ground-floor wall you want to remove. The roof structure — whether it’s a traditional cut roof or a modern trussed rafter system — may be transferring loads down through the same load path.
This is why beam calculations are not a box-ticking exercise. When I work out the size of a steel beam (a universal beam section, sometimes still called an RSJ) for a knock-through, I’m calculating the combined load from all of those sources — dead loads from the structure itself, imposed loads from people and furniture, and any roof loads that travel down through the wall. Get the beam size wrong and you end up with a beam that deflects excessively, or worse, one that isn’t safe under full load.
The beam also needs adequate bearing at each end — usually onto a padstone, which is a block of dense concrete or engineering brick that spreads the point load from the beam end into the supporting wall or pier below. Padstone size is part of the structural calculation, not an afterthought.
Temporary Propping: The Part People Overlook
Before any masonry comes out, the structure above needs to be supported. This is done using Acrow props and a system of temporary needles or spreader beams — essentially a temporary load path that keeps the floor and wall above stable while the permanent steel is installed.
Inadequate propping is one of the most common causes of problems during knock-through work. I’ve seen cases where props were placed too far apart, or where the spreader beam above wasn’t stiff enough to distribute the load properly, leading to cracking in the plasterwork above — or worse, movement in the structure. The propping scheme needs to be thought through properly, ideally by the engineer who has done the beam calculations, so the builder knows exactly where to place the props and how to sequence the work.
This isn’t about being overly cautious. It’s about making sure the job goes smoothly and the builder isn’t left guessing during a critical phase of the works.
Building Regulations and Building Control Sign-Off
Removing a load-bearing wall is notifiable work under Part A (Structure) of the Building Regulations in England. That means you need Building Control involvement — either through your local authority or a private approved inspector. You cannot simply do the work and hope nobody notices. If you come to sell the property, your solicitor will ask for evidence of Building Regulations approval, and if it isn’t there, the sale can stall or fall through entirely.
The process is straightforward when it’s set up properly. The structural engineer produces calculations and a specification — covering the beam size, padstone details, propping requirements, and any other structural elements. Those documents are submitted to Building Control before work starts. A Building Control officer will inspect the works at key stages, typically when the beam is installed and before it’s boxed in. At the end, you receive a completion certificate, which is the document that confirms the work was done to the required standard.
Approved Document A provides the technical framework that Building Control uses to assess structural work. Your engineer’s calculations need to demonstrate compliance with that framework, which is why calculations from a chartered structural engineer carry weight with Building Control officers — they know the work has been done properly.
Party Wall Obligations in Terraces and Semis
If the wall you want to remove is a party wall — shared with a neighbouring property — you have additional legal obligations under the Party Wall etc. Act 1996. This applies in terraced houses and semis where the structural wall sits on or close to the boundary between two properties.
The Act requires you to serve written notice on your neighbour before the work begins, giving them the opportunity to consent or to appoint a party wall surveyor. This is separate from Building Regulations — you need both. The party wall process protects your neighbour’s interests and, frankly, it protects you too, by creating a formal record of the condition of the adjoining property before any work takes place.
If your neighbour consents in writing, the process is quick. If they don’t, a party wall award is drawn up by surveyors, which sets out how the work will be carried out and managed. It adds time and cost, but it’s a legal requirement and not something to skip.
What Does It Actually Cost?
I’m often asked about removing a load-bearing wall cost, and the honest answer is that it depends on several variables — the span of the opening, what’s sitting above the wall, whether the beam needs to be a single section or a compound arrangement, and the complexity of the propping required.
What I can tell you is that the structural engineering fees — beam calculations, padstone design, and Building Control submission documents — are a relatively small part of the overall project cost. The builder’s labour, the steel fabrication, the making-good of plasterwork and floor finishes, and any kitchen or joinery work that follows are typically the larger items. Cutting corners on the structural design to save a few hundred pounds rarely makes sense when the rest of the project budget runs to several thousand.
Getting the engineering right at the start also avoids the costly scenario of having to re-prop, re-specify, or redo work because Building Control has raised a query that wasn’t addressed in the original design.
When to Call a Structural Engineer
Call a structural engineer before your builder starts — ideally before you’ve even had the builder quote, so the scope of work is properly defined. If you’re not sure whether the wall is load-bearing, that’s reason enough to pick up the phone. If you know it is load-bearing and you’re ready to proceed, you need beam calculations and Building Control submission documents before anyone starts propping or cutting. And if the wall is shared with a neighbour, factor in the Party Wall Act timeline too. Getting a structural engineer involved early makes the whole project run more smoothly — for you, for your builder, and for Building Control.
Need expert eyes on your project?
I am a Chartered Structural Engineer (CEng, MIStructE) based in Huddersfield. The Beam Doctor offers homeowners and builders:
- Structural Engineer’s Report from £350 — a signed diagnosis of cracking, movement or defects with a remedial specification for lenders, insurers or your builder. Request a report →
- Steel beam (RSJ) calculations from £295 — Eurocode-compliant, Building Control-ready, in 5 working days. See all services →
- On-site attendance from £225 — a Chartered Engineer at your property, tiered by duration. See site visit fees →