Do I need a structural engineer and drawings?

[jwilf]

So we are looking to refurbish and alter the layout of our downstairs. Small terraced ex-council house in South London. We want to remove the wall between the kitchen and living room, and make the kitchen window wider.

The wall is brick but I'm not sure if it is load-bearing or not - there is no wall directly above it but it might be supporting the bedroom floor joists. As for the window, it's a solid brick wall (no cavity) and the window has a concrete lintel above. A longer lintel will be needed.

My first time doing a project like this and not entirely sure where to start. Should I go to a structural engineer/draftsman and get proper plans make before getting building quotes? Or just go to builders with my own rough plans and ask them to figure it out?

Any advice/experiences would be appreciated

Window: it depends how much wider you want to make it. Unless you're making it very wide (for large bifold doors, for example) the lintel will be a standard, off-the-shelf item and can be specified by the lintel manufacturer, BUT there are rules on how much opening you can have in a given length of wall, before the masonry becomes unstable.

Dividing wall: You can find out which way the joists span by lifting the carpet in the upstairs rooms. If you've got floorboards, the joists will span at 90 degrees to the direction of the floorboards. If you've got chipboard, it can be a matter of looking at the pattern of screws to work out which way the joists run, or at worst using a stud detector. On larger properties, the wall can sometimes be serving a 'butressing' function, even if it's not carrying the floor loads, but that's unlikely in your situation.

You will need Building Regulations approval, but you can do this sort of work under what is called a 'Building Notice' (instead of submitting plans for approval, you just notify them that you are doing the work and they'll come out and check it as it's in progress), so provided Building Control check the lintels, it should be OK to let a competent builder handle it on their own.... If Building Control think calculations are necessary for the beams./lintels, they will ask for them.

Thanks Sensus. We are not going for bifold, we just want to widen the window by about 60cm, so it should be a standard lintel.

For the wall, well I know that the joists run perpendicular to the wall, so it is probably supporting them to some extent, but the thing is there are also beams running across the house parallel to the wall that are supporting the ceiling. I expect a builder could easily see whether an RSJ is needed or not.

I think that what I'm going to do is draw up my own plans and write a spec of exactly what work I want done, and send it to a few local builders for quotes.

Builders often want to see the drawings for the steel. That's what we are finding at the moment anyway. We've had the calcs done by a structural engineer.

Thanks kirinm - what kind of work are you having done?

We are just planning an extension which will take out part of an exterior wall . My dh has done scale drawings and we went straight to builders , having found one that we want to work with he has now found us a structural engineer who is coming to look at an deal with the steel work . I think by doing it this way the builder will be working with people that they normally deal with rather than having loads of different opinions IYSWIM .

Ours is quite a small job. Removing a partially loading wall and a non-loading wall to make a big open plan living/ kitchen room. It's complicated by the fact it's a flat so comes with every legal process you can imagine!

It takes at least 7 years of training via a degree and post grad to be a Structural Engineer - but a builder knows just as much!??? It’s a bit like asking a care assistant to operate on your brain. I can see that your job isn’t particularly challenging but the builders should insist on proper calcs and advice. Not least about supporting the floor above as they demolish the wall.