Hi,
I'd really appreciate a bit of advice on the feasibility of our project and any approximate cost if possible.
We are looking to install 23m2 (6.6x3.5m) mainly glass single storey extension on the back of our French stone farmhouse as per the pics if I managed to include them correctly.
First of all, with regards to opening up the back wall of the house, ideally we would like to take out what is currently a patio door and a window to create a full width opening spanning 5m. We have had 2 local Macons quote for this and both believe that we will need a central supporting column of about 60cm diameter. Is this really the case? Would a correctly sized 5m RSJ/UB really not be sufficient to support the back of the house? For comparison sake, roughly how much would labour and materials for this aspect cost in the UK?
Likewise, for the garden side of the extension, would a single RSJ/UB be suitable to span the approx 6.5m above the patio doors? And also one of 3.3m for the return side? How large would the column have to be to support these 2 beams where they meet?
As for the roof, from what I've seen online, a standard warm flat roof procedure in the UK is something along the lines of 150mm joists followed by timber deck board, a VPL, 150mm ish of PIR followed by a membrane etc amounting to a depth of no more than 35-40cm. Does this sound about right and is that suitable for an extension 6.6x3.5m? Would the joists sit within the RSJs/UBs?
The main stumbling block here and the reason for the questions is that Carpenters don't seem to want to consider any kind of flat roof and the stone masons want to use concrete block resulting in a roof depth of around 70cm all in which is far too thick for our project.
Finally, what would be the rough cost for installing the 6.6x3.5m concrete slab in the UK?
Sorry for all the questions but any help would be most appreciated as we are on the verge of abandoning our project out of frustration.
Thanks
p.s for anyone wondering, we originally proposed a stone extension in keeping with the original house but the planners would only permit a contemporary structure with as much glass as possible..
I'd really appreciate a bit of advice on the feasibility of our project and any approximate cost if possible.
We are looking to install 23m2 (6.6x3.5m) mainly glass single storey extension on the back of our French stone farmhouse as per the pics if I managed to include them correctly.
First of all, with regards to opening up the back wall of the house, ideally we would like to take out what is currently a patio door and a window to create a full width opening spanning 5m. We have had 2 local Macons quote for this and both believe that we will need a central supporting column of about 60cm diameter. Is this really the case? Would a correctly sized 5m RSJ/UB really not be sufficient to support the back of the house? For comparison sake, roughly how much would labour and materials for this aspect cost in the UK?
Likewise, for the garden side of the extension, would a single RSJ/UB be suitable to span the approx 6.5m above the patio doors? And also one of 3.3m for the return side? How large would the column have to be to support these 2 beams where they meet?
As for the roof, from what I've seen online, a standard warm flat roof procedure in the UK is something along the lines of 150mm joists followed by timber deck board, a VPL, 150mm ish of PIR followed by a membrane etc amounting to a depth of no more than 35-40cm. Does this sound about right and is that suitable for an extension 6.6x3.5m? Would the joists sit within the RSJs/UBs?
The main stumbling block here and the reason for the questions is that Carpenters don't seem to want to consider any kind of flat roof and the stone masons want to use concrete block resulting in a roof depth of around 70cm all in which is far too thick for our project.
Finally, what would be the rough cost for installing the 6.6x3.5m concrete slab in the UK?
Sorry for all the questions but any help would be most appreciated as we are on the verge of abandoning our project out of frustration.
Thanks
p.s for anyone wondering, we originally proposed a stone extension in keeping with the original house but the planners would only permit a contemporary structure with as much glass as possible..