Removing a load-bearing wall is one of the most popular structural alterations London homeowners undertake — typically to create an open-plan kitchen/dining/living space by knocking through the ground floor. It is also one of the most frequently underestimated in cost. Here is an honest guide to what is involved and what it costs.
What is a load-bearing wall?
A load-bearing wall carries the weight of the structure above it — upper floors, roof structure, or both. In a typical two or three-storey London terrace, the walls running from front to back of the house (parallel to the party walls) are usually load-bearing. So are the walls directly above on each floor.
Not all walls are load-bearing. Partition walls within a floor plan often are not. The only reliable way to confirm which walls are load-bearing is to have a structural engineer assess the property. Never assume a wall is non-load-bearing without professional confirmation.
How much does load bearing wall removal cost in London?
For a typical ground-floor opening in a terraced or semi-detached house (removing the wall between the kitchen and the rear reception room), the cost is:
£4,000 – £8,000 for the structural alteration itself — including temporary propping, removing the wall, installing the steel beam (RSJ), making good plaster, ceilings, and flooring across the junction.
This range reflects the size of the opening, the type of beam required, and how complex the propping and making-good work is. A 2-metre opening requires a smaller beam than a 4.5-metre opening running the full width of the house.
Additional costs you need to budget:
- Structural engineer's fees: £500–£1,200 for initial design, drawings, and specification. Essential — do not proceed without one.
- Building Regulations: £400–£700 for a structural alteration. We manage this as part of the project.
- Decoration: making good plaster and painting the new open space — typically £500–£2,000 depending on the room area and finish level.
Total project cost for a standard rear ground-floor opening: £5,500–£12,000.
What size steel beam do you need?
The size of the steel beam (RSJ — Rolled Steel Joist, or sometimes a UC section) is specified by the structural engineer based on:
- The width of the opening
- The load being carried (one floor above, or two floors, or roof structure)
- The bearing condition at each end (padstones, lintels, or pockets in the existing brickwork)
- Any point loads from above (such as a chimney stack directly on the wall being removed)
For a typical 2.4–3.6 metre kitchen opening between two ground-floor rooms carrying one floor above: a 152×89 or 178×102 UC section is common. For a full-width opening (4–6 metres), a heavier section or a parallel flange channel (PFC) may be required. The engineer sizes this correctly; guessing is not acceptable and will fail Building Control inspection.
Does removing a load-bearing wall need Building Regulations approval?
Yes, always. Any structural alteration that removes or modifies a load-bearing element requires Building Regulations approval. This involves:
- Notifying Building Control before work starts
- An inspection when the temporary propping is in place
- An inspection when the steel beam is in place before making good
- A final inspection
We manage the full Building Regulations process as part of every structural alteration. You receive a Building Regulations completion certificate at the end, which is required when you sell the property.
How long does load bearing wall removal take?
The structural alteration itself — propping, demolition, beam installation, and initial making good — typically takes 2–5 days on site for a standard opening.
Total programme from instruction to completion (including structural engineer, Building Control notification, and making good) is typically 3–6 weeks. The structural engineer's design and any lead time on the steel are usually the longest elements.
Do you need planning permission to remove a load-bearing wall?
In most cases, no — internal structural alterations to a house are permitted development and do not require a planning application. The main exceptions are listed buildings (where listed building consent is required for any internal alterations) and some conversions where planning conditions restrict internal works. We confirm this on every project.
What happens if you remove a load-bearing wall without structural support?
The consequences range from cracking and settlement to partial or full collapse, depending on how much load the wall was carrying and how quickly the issue develops. We have seen properties where informal removal of internal walls has caused progressive cracking across multiple floors over months or years. Retrospective remediation is significantly more expensive than doing it correctly first time.
Combined with a rear extension
The most common scenario we handle is a rear extension combined with a structural opening into the existing house — creating one large open-plan kitchen/dining/living space across the extension and original ground floor. The structural alteration and the extension are usually contracted together as a single project. We manage the structural engineer's input across both elements as part of the same package.
Prices in this article reflect London market conditions as of Q3 2026. Your actual cost depends on the specific opening width, load, and property type.