Building Regulations for kitchen diner with staircase and removal of side door

[CornyCob]

We're looking to take out the load bearing wall between our kitchen and dining room, block up the external side door in the kitchen and add a new internal door into the garage (as per plans below). I understand we will need buildings regs approval for the works but was just wondering if there's anything beyond the expected that may be a stumbling block? Particularly with respect to fire regs as the stairs would now be in the kitchen diner (it's a 2 storey detached house) and whether blocking up the side door would impact this? The staircase is currently not enclosed but is open within the dining room and there are double patio doors into the garden at the rear of the dining room.

I understand we will need the standard structural calcs for the RSJ and a self closing FD30 door into the garage with a 100mm step but is there anything else I'm missing?

Thanks in advance.
 

[Mr Punter]

Kitchen open to stairs on the escape route is not good.  Each upstairs room will need an escape window and you may need additional smoke / heat sensors.

[Temp]

+1

 

The BCO won't like and night not allow the upstairs escape route to be via the kitchen.

 

[kandgmitchell]

The means of escape requirements of the Building Regulations say:

 

Escape from upper storeys a maximum of 4.5m above ground level
2.2 See Diagram 2.1b. Where served by only one stair, all habitable rooms (excluding kitchens) should
have either of the following.
a. An emergency escape window or external door, as described in paragraph 2.10.
b. Direct access to a protected stairway, as described in paragraph 2.5a.

 

So hopefully the OP's first floor windows comply with a) above already. If they do then forming the through room will not have an impact whatever the ground floor room use.

 

However, if the first floor windows do not comply, the OP's argument that they are not making the M of E situation any worse than it is at present (i.e neither escape windows nor a protected stair exists as is) could be countered by Building Control saying that the kitchen is a high risk room and the present stair is separated from it, despite not being protected. The risk must therefore increase and thus the proposal makes an existing non-compliant situation worse which contravenes Regulation 4(c).

 

So check those first floor windows!

 

Oh and the garage fire door needs to be an FD30S

 

[CornyCob]

22 hours ago, kandgmitchell said:

The means of escape requirements of the Building Regulations say:

 

Escape from upper storeys a maximum of 4.5m above ground level
2.2 See Diagram 2.1b. Where served by only one stair, all habitable rooms (excluding kitchens) should
have either of the following.
a. An emergency escape window or external door, as described in paragraph 2.10.
b. Direct access to a protected stairway, as described in paragraph 2.5a.

 

So hopefully the OP's first floor windows comply with a) above already. If they do then forming the through room will not have an impact whatever the ground floor room use.

 

However, if the first floor windows do not comply, the OP's argument that they are not making the M of E situation any worse than it is at present (i.e neither escape windows nor a protected stair exists as is) could be countered by Building Control saying that the kitchen is a high risk room and the present stair is separated from it, despite not being protected. The risk must therefore increase and thus the proposal makes an existing non-compliant situation worse which contravenes Regulation 4(c).

 

So check those first floor windows!

 

Oh and the garage fire door needs to be an FD30S

 

Thanks for the detailed reply. Just check and all the windows comply with the minimum areas and dimensions but I'm a bit unclear on part iii:

'iii. The bottom of the openable area is a maximum of 1100mm above the floor.'

All the windows are approximately 1100mm to cill level from the floor, but the window frame then sits above this meaning it's probably ~1180mm to the actual openable area. How strict are building control likely to be on enforcing this/does anyone actually check exact heights to each frame?

 

[kandgmitchell]

Those cill heights are high then. "Does anyone check..." That's a hard one because some BCO's may think of it and others may not - you're in the realms of an individual's attitude and interpretation. I could be more certain if the opening height was compliant. In your situation I'd submit a "full plans" application - you can do the drawings yourself as they'll only be floorplans of before and after. You'll need the SE's calcs for the beam (but you'll want them anyway). This would allow you to get BC's attitude to the situation on paper (i.e comments back as part of the checking process)  rather than having done the work and getting any bad news on site which could be the case with a Building Notice.