Taking out a wall is a structural question with a decorating disguise

These are listed in the order worth acting on, which with removing internal walls is not the order they are usually presented in.

What a wall might be doing

An internal wall may carry floor joists, roof loads, another wall above, or nothing structural at all beyond its own weight. It may also be providing lateral restraint, holding the outer walls of the building against movement, which is easy to overlook. The direction the floor joists run above is a strong clue, since a wall running across the joists is more likely to be carrying them.

Thickness and material are weaker clues, because a slender wall can be loadbearing and a thick one can be a later partition. None of these observations replaces a proper assessment, which is why the first step is always someone qualified looking at it.

Where the load goes instead

Removing a loadbearing wall means substituting a beam that spans the opening and transfers the load to a support at each end. Those supports concentrate what was a spread load into two points, and whatever is beneath them has to be able to take it. That frequently means the floor structure and sometimes the foundation below has to be checked and occasionally strengthened.

Underneath it, the beam has to be designed for the loads it will carry, and that calculation is the work of a structural engineer. A beam sized by guesswork may not fail immediately, which is precisely what makes an undersized one dangerous.

Deflection, cracking and what shows later

A beam that is strong enough may still deflect enough to crack the plaster and jam the doors of the rooms above. Design therefore considers stiffness as well as strength, and limiting deflection is usually what determines the size. Temporary support during the work carries the load while the wall comes out, and inadequate propping is a common cause of collapse.

Cracking that appears months after a removal is worth having looked at rather than filled, since it may be telling you something. Movement is normal in small amounts and progressive movement is not, and the distinction requires someone who does this professionally.

What else is inside the wall

Cables, pipes, waste runs and sometimes a flue pass through internal walls, and all of them have to be rerouted before demolition. Rerouting electrical circuits and gas is regulated work in most countries and must be done by an appropriately qualified person.

Over years, radiators mounted on the wall lose their position, which changes the heating layout of both rooms. Switches and sockets on the wall have to reappear somewhere, and the obvious new locations are often inconvenient. Older walls can contain materials that must not be disturbed, which is another reason for a survey rather than a hammer.

The consequences after the dust settles

Two rooms become one, and the acoustic separation that made one of them quiet is gone permanently. Heating changes, because a larger volume takes longer to warm and heat escapes towards the coldest part of the new space.

Live with it a while and cooking smells and noise travel throughout the combined space, which is the most common regret reported after this kind of work. Wall space for furniture is lost, and the loss is often more than the plan suggested because both faces have gone. A structural opening left as a wide doorway rather than a full removal keeps some separation while gaining most of the connection.

Anything structural belongs with a qualified professional, not an article.

Getting it done properly

The sequence is assessment, design, approval, temporary support, removal, then permanent support, and skipping steps is where things go wrong. In most countries this work requires notification or approval from a local authority, and the process differs considerably between them.

Insurance and future sale both depend on the paperwork existing, and retrospective approval is harder and more expensive to obtain. Party wall arrangements may apply where the wall or the beam bearing is shared with a neighbour, and those rules also vary. A structural engineer, a building control process and a competent contractor are the three things that make this a routine job rather than a risk.

Everything above, in order of what to do first

1. What a wall might be doing. An internal wall may carry floor joists, roof loads, another wall above, or nothing structural at all beyond its own weight.
2. Where the load goes instead. Removing a loadbearing wall means substituting a beam that spans the opening and transfers the load to a support at each end.
3. Deflection, cracking and what shows later. A beam that is strong enough may still deflect enough to crack the plaster and jam the doors of the rooms above.
4. What else is inside the wall. Cables, pipes, waste runs and sometimes a flue pass through internal walls, and all of them have to be rerouted before demolition.
5. The consequences after the dust settles. Two rooms become one, and the acoustic separation that made one of them quiet is gone permanently.
6. Getting it done properly. The sequence is assessment, design, approval, temporary support, removal, then permanent support, and skipping steps is where things go wrong.

The takeaway

Have it assessed, have the beam designed, get the approval, and treat the propping as seriously as the beam.

A room that is used will always beat a room that is finished.