How much does it cost to knock down an internal wall?

For a standard non-load-bearing stud wall — the kind made of timber and plasterboard — you are typically looking at 400 to 800 pounds including removal, making good the ceiling and floor where the wall was, and disposal of waste. The job usually takes a day. If the wall is blockwork rather than stud, add another 200 to 300 pounds because the demolition is heavier and produces more waste. Always confirm whether the wall is load-bearing before any work starts. A structural engineer's inspection costs around 300 to 500 pounds and is money well spent.

If the wall is load-bearing, the cost increases substantially. You will need a structural engineer to design a steel beam (RSJ) or concrete lintel to carry the load above. The beam itself, plus installation, propping, and building control sign-off, typically adds 1,500 to 3,500 pounds to the project depending on the span and load. Building regulations approval is required for any structural alteration, and your builder should submit a building notice or use an approved inspector. Do not skip this — it will cause problems when you come to sell the property.

Hidden costs catch people out. Walls often contain electrical cables, radiator pipes, or gas supplies that need rerouting before demolition. Budget an extra 200 to 600 pounds for first-fix electrical and plumbing alterations. You will also need plastering to make good the adjoining walls and ceiling — typically 300 to 500 pounds depending on the area. Flooring is another consideration. If the rooms either side had different floor coverings, you will need to match or replace the flooring across the new open-plan space. Get an itemised quote that covers all these elements.