External wall - RSJ/concrete lintel

[cam1989]

Evening all.

I'm in the process of buying a house. On one end of the house are two external coal bunker type structures (one next to the other, split by an internal wall). These have been built onto the side of the house, rather than into it.

Our current intention is to knock through into this space to make use of it. We currently rent an identical house, which has had this done - so I've taken measurements from this.

The width of the coal bunkers is around 2300mm. The external wall is a cavity wall, measuring 300mm thick (inc. a layer of plaster both sides).

So, before I go getting quotes and nodding along with everything that the builder says, are we looking at an RSJ for this or a concrete lintel? What sort of time are we looking at to complete the works? (I'm not too bothered about them knocking the wall out or making good, as I can do that sort of thing myself), just having the support in place.

Finally (and I've no doubt it'll be 'about the price of a second hand car'), what sort of price should I be looking at for this? Hundreds? Thousands?

 

[tony1851]

On a 2.3m span, steel beams are more practical than concrete. If it's a cavity wall, you'd be looking at two 152x89 beams.
(don't know about £££?).