Removing a wall and other internal alterations

Want to knock the kitchen and the dining room into one, or open up a poky little hallway, and somebody has told you that the wall in question might be holding the house up?

Internal alterations are the most consistently underestimated work we deal with. There's no planning application to make, nothing changes outside, the neighbours never even know it's happening, and the whole thing feels like something you could just crack on with over a long weekend if you had a decent hammer and a skip. Then the wall comes out and within a fortnight the bedroom floor upstairs has a noticeable dip in the middle of it.

No, in almost every case, because planning is concerned with the outside of your building and internal alterations don't change it in any way a planning officer cares about.

The exception, and it's a big one, is a listed building. Internal work to a listed building needs Listed Building Consent even though nobody can see any of it from the street, and original internal walls, staircases, plasterwork and fireplaces are very often precisely what is listed about a listed building in the first place. Doing that work without consent is a criminal offence rather than a planning breach, so please check before you touch anything. There's more on what needs permission and what doesn't if you're unsure where your property stands.

If the wall is structural then yes, definitely, and there's no way round it.

You need approval, you need structural calculations, and you need the work inspected while it's happening rather than after it's plastered. And you need the completion certificate at the end of it, because that's the document a buyer's solicitor will ask for when you sell the house, and a structural alteration with no paperwork is one of the more awkward things to explain in a conveyance.

You can get a reasonable idea yourself, and then you get it properly checked, because being reasonably sure is nowhere near good enough when a floor and possibly a roof is sitting on top of it.

Start with the thickness. In an older house a solid wall a full brick thick is very likely to be structural, whereas a stud wall you can knock on and hear a hollow sound behind usually isn't, though not always, because plenty of structural walls have been dry lined at some point and sound hollow when they're anything but.

Then look at what's directly above it. If there's a wall in the same position on the floor above then that's a strong indication, and if you can get up into the loft it's worth seeing whether anything is bearing down on that line from the roof structure.

The most useful test is the direction of the floor joists upstairs. Joists span the shortest distance available and they rest on walls at each end, so if they run at right angles to your wall then it's very probably carrying them, and if they run parallel to it then it very probably isn't. You can often work out which way they run from the direction of the floorboards, because boards are laid at right angles to the joists underneath them.

And on the ground floor, look at whether the wall is sitting on its own foundation rather than just on the slab, because a structural wall will usually have a footing of its own underneath it.

All of that together gives you a good working idea. None of it is certain, because houses get altered by people who didn't record what they did, and the obvious answer is sometimes flatly wrong. Please seek advice before you knock anything down!

The wall gets replaced by a beam, usually steel, spanning the new opening and carrying everything the wall was carrying before it.

That beam has to be sized by calculation rather than by eye or by what somebody used on a project down the road, because the load it's carrying depends on what's above it and how far it has to span. Its ends bear onto something, and that something is normally a padstone, which is a solid block spreading the load out into the masonry below rather than concentrating the entire weight of the floor above onto three or four bricks that were never asked to do anything of the sort.

Then the load has to have somewhere to go all the way down to the ground. If the wall directly below your new beam bearing is itself sitting on nothing very much, then you haven't solved the problem, you've just moved it down a floor where it'll show up later, and on a ground floor opening that can mean new foundations under the bearings.

And while all of that is going on, the floor above has to be held up temporarily, properly propped, with the props themselves standing on something capable of taking the load rather than on a suspended timber floor.

None of this is dramatic when it's been designed. All of it goes badly when it hasn't.

This is the part almost nobody thinks about and it catches people out at the final inspection, which is the worst possible moment.

In a two storey house your staircase is your escape route, and the hall it lands in needs to stay reasonably protected so you can actually get out through it with a fire going. Knock that hall through into an open plan living room and kitchen, which is exactly what a great many people want to do, and your only escape route now runs directly through the room statistically most likely to be on fire.

There are ways to deal with it and we design round it regularly. A protected alternative route, a window large enough to escape from in a habitable room, sometimes a sprinkler or a domestic misting system. But every one of those has to be designed in from the start rather than discovered afterwards, and this is easily the most common reason we see open plan schemes come back needing changing.

If you've got three storeys, or a loft conversion already, the requirements get considerably tighter again.

There's usually more inside a wall than people expect. Sockets, switches, cables running up to the floor above, sometimes pipework and occasionally a soil pipe. All of it needs rerouting properly, and any electrical work needs certificating under Part P.

Worth thinking too about where things end up afterwards, because this is the bit that gets forgotten in the excitement of a big opening. Knock two rooms into one and you can easily end up with a long room that has no sockets at all down one side and a radiator sitting in the middle of what's now the main walkway.

And it may be darker than you expect. Two rooms each with a window become one long room with a window at either end and a distinctly gloomy middle, which is a very common outcome and people are genuinely surprised by it because the drawing looked perfectly fine. Rooflights help if there's a single storey section, borrowed light helps, and thinking about where the kitchen sits relative to the windows helps most of all. It's the sort of thing that gets sorted out on a drawing in ten minutes and can't be sorted at all once the plaster is on and the units are fitted.

Some of it, yes. Plenty of people do their own strip out, take the plaster off, get the room back to brick and clear the debris, and there's nothing wrong with that if you're careful about what's in the wall before you start swinging at it.

The structural work is different. Not because you couldn't physically do it, but because it needs designing, it needs propping correctly, and it needs inspecting by Building Control at the right stages. An inspector turning up to find a beam already sitting on bearings he never got to see is a conversation that ends with things coming back apart. And if you're intending to sell the house at any point in the next twenty years, the paperwork matters as much as the work.

Two things catch people out at the finishing stage and both are worth planning for.

Floor levels between the two rooms are rarely identical, particularly in older houses where one room might have been a scullery with a solid floor and the other has suspended timber. A difference of even twenty or thirty millimetres shows badly once you've got one continuous floor covering running through, and levelling it is easier to design for than to solve on site.

And the ceiling will show where the wall was, because there'll be a line of new plasterwork running across it and possibly a slight difference in level between the two original ceilings. It can be dealt with, either by accepting a visible downstand where the beam sits or by taking the ceilings down and starting again, but the two answers cost very different amounts and it's better to choose than to discover.

Get it surveyed and designed before anything comes out.

We work out what's structural and what isn't, size the beam, produce the calculations and the Building Regulation drawings, and deal with Building Control on your behalf. And if the wall you want to take out happens to be shared with a neighbour, we'll tell you whether the Party Wall Act applies well before it turns into a problem.

For more information please call us on 07773 899 597 or contact us through this website.