House Renovation - Cost Estimate - Taking down structural walls and moving a doorway

[Bumblebee1812]

Evening all,

We are buying a house where we wish to open up three rooms in to one big family space. This will involve taking down two structural walls and also moving a doorway. I am aware of the cost to have the steel beams calculated by the structural engineer.

Work will be as follows:

1. Open up a wall which is 3.1m long
2. Open up a second wall, which is 3.5m long. This wall does already have a double doorway between the two rooms.
3. Add a single doorway
4. Blocking up three doorways

Does anyone have any experience of how much builders have charged to complete similar work? We are in the South East.

TIA

We had some structural work as part of an extension. Our beams cost about £1k each plus the same again for the labour to install them. The doorways should be about 1 days labour to construct. You will then need to add plastering, decorating and any electrical costs e.g for moving light switches etc.

Thanks @weepingwillow22. That's a lot cheaper than I was expecting. Fingers crossed ours isn't significantly more!

Yes I would agree around 2k per beam (if you've already had the structural engineer calcs done), plus a bit for finishing (one day of plastering and decorating).

Opening and blocking doorways is fairly cheap. What gets expensive is if you then have to redo flooring (as thresholds are in the wrong place) and wiring (eg to move the light switch to new location)

Taking down walls - it all depends. We opened up a 7.5m span with 2 stories on top so that needed some fairly serious steelwork to support it, plus we wanted the steel recessed into the ceiling not hanging down, and in London, so that was pretty expensive. Are your 3m spans separate, you aren’t wanting to connect them together to make one big one? If so then cheaper.

If you're on a budget OP - you might want to consider getting a 2nd hand RSJ that meets or exceeds your spec - Have a look on eBay. Even including rental of a Jumbo Transit to go collect it could save you heaps.

Although 3.5m beams probably won't cost that much anyway.

I’m in Yorkshire. Beams generally cost £1000 each and the calculations for each beam are £300. Building control will be needed, their costs will be found on or via your council website.
If the floors aren’t the same level and need relaying that’s where is gets really expensive with the costs of skips and labour

If you're removing walls you'll need building control to sign off on the work and there are fees involved there. The structural engineer's calcs will need to be shared with building control. It's not as expensive as you might think, but you'll need to allow for the structural engineer's fees, building control, steels and construction work.

Thanks @bravotango. That doesn't seem too bad then.

@minipie thanks for the feedback. Yes the two RSJ's will be separate. Noted in respect of the floor. We are having a full rewire anyway, so not to worried about the wiring.

@FurierTransform that's such a good tip, although I think we will be fine to buy them new. Thank you.

@gonewiththerain thanks for the advice. I think I need to just check if building regs sign off will be a flat fee or per beam. I'll look in to it.

Thanks @wowfudge. That's really helpful.

Thanks everyone!