Knocking through a load-bearing wall: what is involved

The wall between a kitchen and a dining room is the one most often taken out, and very often it is holding something up. That does not stop it being removed. It means the load has to be picked up by something else first, and that something has to be designed, approved and installed in the right order.

Is the wall load-bearing?

Honestly, you need someone to look at it. The Planning Portal advises getting a structural engineer’s report even to confirm that a wall is not load-bearing before you remove it.

There are signs, though:

• Joists landing on it. Lift a floorboard in the room above. If the joists run at right angles to the wall and rest on it, it is almost certainly carrying them.
• What it is built from. Solid brick or block is more likely to be structural than a hollow stud partition, though stud walls can carry load too, especially in older houses.
• What is above it. A wall directly beneath another wall upstairs is often carrying it.

None of these is conclusive. Plenty of walls carry more than they appear to.

The engineer, and the beam

A load-bearing wall coming out needs structural calculations from an engineer. They work out what the wall supports, size a beam to carry it, and specify what it bears onto at each end. Building control checks the work against those calculations, and a buyer’s surveyor will ask for them when you sell.

Most openings use a steel beam, because it carries a lot of load for its depth. Depending on span and load, the engineer may specify a timber or engineered timber beam, a flitch beam (timber with a steel plate bolted between), or a concrete lintel for a small opening.

A beam is also part of the structure for fire purposes. The Approved Document on fire safety sets a minimum fire resistance for beams, which is why a steel is normally boxed in rather than left bare.

Padstones and temporary support

The beam ends usually sit on padstones, solid concrete blocks that spread the load into the wall below. Sometimes the wall or foundation underneath cannot take that concentrated load, and a new pier or foundation is needed.

Before the wall comes out, everything above it is propped. That means adjustable steel props, either under the ceiling or under needles (short beams passed through holes cut in the wall above the opening), or proprietary support heads slotted into the brickwork. The wall comes out, the padstones go in, the beam is lifted in and packed tight, and only then do the props come out.

Building regulations and planning

Removing a load-bearing wall needs building regulations approval. The Planning Portal is direct about it: it alters the structure of the property, and you will need a structural engineer’s calculations. Building control inspects the work, and at the end you should get a completion certificate. Keep it with the calculations.

Planning permission is usually not needed. The Planning Portal’s guidance is that internal alterations, including removing an internal wall, should not need it. The exception is a listed building, where listed building consent is needed for significant works inside or out, and doing them without consent is a criminal offence.

Party walls and chimney breasts

If the beam bears into a wall you share with a neighbour, the Party Wall etc. Act 1996 applies. Cutting into a party wall is notifiable, and the notice must be served at least two months before work begins. On semis and terraces, the party wall is often the obvious place for one end of the beam. See our article on party wall notices.

If there is a chimney breast on the wall, removing it means supporting whatever is above, including any stack, which is structural work for the engineer and building control. Cutting away a breast from a party wall is covered by the Act as well.

Fire safety and open-plan layouts

This is the part that gets missed.

Where the stairs come down into a hallway, that hallway is often the escape route from upstairs. Open the kitchen onto it and a kitchen fire has a direct route to the stairs.

In a two-storey house, upstairs rooms normally rely on escape windows, so there is more latitude. In a house with a storey more than 4.5 metres above ground (typically three storeys, or a loft conversion), the Approved Document expects a protected stairway: a stair enclosed in fire-resisting construction all the way to an exit. Opening the kitchen onto it can break that protection, and the Building Regulations require the house to be no less satisfactory on means of escape after the work than before.

There are solutions, including sprinklers combined with fire separation, but they need agreeing with building control before the wall comes out.

If your knock-through is between kitchen and dining room and the hall is untouched, this may not apply. If you are opening up to the hall in a house with a loft room, it almost certainly does.

What else moves

• Radiators and their pipework need a new home.
• Sockets, switches and cables in the wall need rerouting. If that means a new circuit, it is notifiable under Part P.
• Floor levels. Two rooms built separately often have floors at slightly different heights. Joining them means levelling one to the other, and usually new flooring through both.
• Ceilings need making good where the wall met them.

What drives the cost

We do not publish prices, because the cost depends on things that vary a lot between houses:

• Span and load: a longer opening, or one carrying a wall and roof above, needs a bigger beam, sometimes more than one
• Where the beam bears: sound brickwork is simple; a party wall, a chimney or a new pier is not
• Below or within the ceiling: setting the beam up into the floor zone looks better and is more work
• Fire safety, if the escape route is affected
• Everything else moving: radiators, electrics, plumbing, flooring
• Fees: engineer, building control and, where needed, party wall surveyors

Doing it with a kitchen or an extension

A knock-through is often part of a bigger job, and that is the cheapest time to do it. If the kitchen is being replaced anyway, the strip out, the moving of services and the making good are already happening. See what a kitchen renovation involves.

Opening the back of the house into a rear extension is the same principle at a larger scale, designed alongside the extension. See home extensions and kitchen fitting.

What to do next

The first step is not a price for the wall. It is finding out what the wall is carrying, and whether an escape route or a party wall is involved.

Tell us about the house: how many storeys, whether the loft is converted, and which wall you want gone, with a photo of each side. Quotations are free, and all our work is guaranteed, with a minimum of 24 months on labour.