Knocking Through to Make a Kitchen-Diner

Is the wall load-bearing?

Many walls between a kitchen and dining room carry weight from floors, walls or the roof above, especially in older houses. Others are simple stud partitions. You cannot tell reliably by knocking on the wall, so the first step is to have it checked. Joists running across the top of the wall, a wall directly above it upstairs or a chimney breast nearby are common signs of a load.

For a load-bearing wall, a structural engineer designs the opening: the size and type of beam, the padstones it sits on, and any temporary support needed while the wall is taken out. Their calculations go to building control or into the building warrant application. We arrange the engineer and the approvals as part of the job.

What approvals are needed in each nation?

Removing a load-bearing wall needs Building Regulations approval everywhere in the UK, but the process differs. Removing a non-load-bearing partition is simpler, though it can still affect fire safety and sound insulation. Planning permission is not usually needed for internal walls, though a listed building may need listed building consent. In summary:

England and Wales: building control approval, with inspections during the work and a completion certificate
Scotland: a building warrant from the council before work starts, then a completion certificate; a non-load-bearing partition does not usually need a warrant in a house, but can in a flat
Northern Ireland: building control approval under the Building Regulations (Northern Ireland) 2012
Listed buildings in any nation: listed building consent may also be needed
Flats: the freeholder's written consent, usually a licence for alterations

Does the Party Wall Act apply?

In England and Wales, the Party Wall etc. Act 1996 may apply if the work affects a wall shared with a neighbour, for example where a new beam bears into a party wall in a terrace or semi-detached house. You then need to serve notice on the neighbour before work starts, and a party wall surveyor may be needed if they do not agree.

The Act does not apply in Scotland or Northern Ireland. Even so, it is good practice to let neighbours know about noisy structural work in advance, and to check their side of a shared wall before and after the work.

What about fire safety and escape routes?

Knocking through can change how people would get out of the house in a fire. In some homes, particularly those with three or more storeys, or where the kitchen would open onto the hall and stairs, the stair may need to stay a protected escape route. Opening it up can mean extra measures, such as fire doors, interlinked alarms or other arrangements.

These rules are detailed and depend on the layout of the house, so building control, or the council's building standards service in Scotland, will look at escape routes as part of the approval. Ask the engineer or designer to check this early, before the kitchen plan is finalised.

How does the work run?

A typical sequence is survey, engineer's design, approval, then the structural work, the kitchen and the finishes. The opening itself usually takes three to seven days, and the whole knock-through one to three weeks before the kitchen goes in. Here is how the structural stage normally runs:

Services in the wall are isolated and rerouted
Temporary supports go in to carry the load above
The wall is taken down and padstones prepared
The beam is lifted in, packed tight and inspected
Fire protection is applied where needed, then the opening is boarded and plastered
The floor is made good where the wall stood

What happens to the floor, ceiling and services?

Where the wall comes out there is a strip of floor to make good, and the two rooms may have different floor levels or constructions, such as timber in one and concrete in the other. Levelling or a new plywood base lets one floor finish run through; for a kitchen-sized floor that is typically £300–£900, and more for a larger kitchen-diner.

Sockets, switches, radiators and pipes in the old wall have to be moved before it comes down. The ceiling along the line of the beam is boarded and skimmed, and the beam is either boxed in below the ceiling or set within its depth, which the engineer decides.

What does a knock-through cost?

These are national guide ranges including VAT at 20%. They vary by region, the width of the opening, the beam needed and how much making good is involved, and they are confirmed after a survey visit once the engineer's design is known. The kitchen and the new floor are the largest parts of a combined project.

Non-load-bearing wall removed and made good: £800–£2,000
Load-bearing wall with a steel beam, including the engineer's design and making good (approval fees listed separately): £3,000–£8,500
Knock-through with a new kitchen-diner and new floor throughout: £25,000–£55,000

Planning the new kitchen-diner

One larger room changes how the kitchen should be laid out. Think about where the dining table goes, whether an island or peninsula will divide the space, and how the cooking area relates to the seating. Radiators on the removed wall need moving, and a larger room may need more heating, possibly underfloor heating under the new floor.

Extraction matters more in an open-plan room, as cooking smells and steam spread into the living space, so a ducted hood is worth the effort. Plan lighting in zones, so the kitchen can be bright while the dining area is softer, and run one floor finish through the whole space so it reads as one room.

Questions

Do I need planning permission to knock through?

Usually not. Removing an internal wall in a house does not normally need planning permission, but it does need Building Regulations approval if the wall is load-bearing, or a building warrant in Scotland. Listed buildings may need listed building consent, and leaseholders need the freeholder's consent before any structural work.

How long does a knock-through take?

The opening itself usually takes three to seven days, including temporary supports, removing the wall, fitting the beam and inspection. With making good, plastering and floor work, allow one to three weeks before the new kitchen goes in. Approvals and the engineer's design come first and can add several weeks before work starts.

Can I stay at home during a knock-through?

Usually, yes, though the dust and noise during demolition are significant. Dust sheets and sealed doorways help, and the noisiest work is concentrated into a few days. The kitchen will be out of use for longer than a straightforward refit, so plan a temporary kitchen elsewhere in the house.

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This guide is general information about kitchen fitting in the UK, not legal, tax, electrical or structural advice for your property. Rules differ between England, Wales, Scotland and Northern Ireland; check with your local authority or a qualified adviser before relying on it.

What is involved in knocking through to make a kitchen-diner?