Kitchen opening using RSJ (Southeast)

Could do with some more information really to decide if it is fair. First of all, you are making a structural change to a load-bearing wall so I am pretty certain you are going to have to get building regs approval and this will most likely require a structural engineer to provide calculations for the size of the steel beam required.

2 months ago we knocked our kitchen wall through to the dining room. We created a 2.1m opening in a 3m long breeze block wall. This is how we did it and the approximate costs involved:

1. Had structural engineer produce drawings and calcs £350 inc VAT
2. I produced some basic drawings (floor plan etc), included the SE's drawings of the beam and padstones and submitted them all to Building Control £120 (IIRC). You can get away with not producing sets of plans and just have them turn up and inspect the work but you still have to pay the same fee and you still need the SE's calcs.
3. I bought the steel beam, £70 delivered. I hired the props and bought the padstones, cement etc. Less than £50 in total.
4. Paid a family friend builder £300 for 2 days with me as labourer (boy, was that hard work). On day 1 we supported the groung floor ceiling, cut and bashed out the wall and installed the beam. Then on day 2, the cement had dried around the padstones so we removed the supports and plasterboarded up the beam. The plastering was done seperately as we were having our whole downstairs replastered anyway, however on day 2 we were done by lunch time so I would expect the plastering to take no more than an afternoon.

You don't say how large the opening is that you are going to create but I would say that at most you are looking at perhaps £100 for a smallish skip for the rubbish. We just did 4 trips to the dump in my GF's dad's 4x4.

So what I am trying to say is that..

A. Have you contacted building control, done calcs etc?
B. Is the quote for all of this stuff? Calcs, Building Regs, the beam etc. Or is it just for a builder and his tea boy to turn up for 2 days and take away the rubbish? If the former then it's probably fair. If the latter then I guess you can make up your own mind based on the cost breakdown I have given you.

Oh and I am in Surrey.

Hope this helps