Roof Truss in Middle of Bedroom

[RonnyRaygun]

I'm currently doing the structural design on the refurbishment of a 1700s cottage.

The owners want to do a loft conversion and are happy to lose two of the three kingpost trusses.
However, they want to retain as many of the original features as possible, and with that in mind they want to retain one of the roof trusses in one of the new bedrooms.

The truss in question can be seen below.

Aside from the practicalities of having to climb over a truss to get to their bed, and the obvious issue of getting funiture past the truss to that side of the room, I can't believe that it would comply with Regs for means of escape. The conversion will creat a new second floor so the new dormer window will not be able to be used as a means of escape.

I have raised this with the architect who has just taken over the job. The previous architect didn't suggest to the client that there would be any problems with this. The client is perfectly happy to have the impracticality of climbing through the truss in order to keep the original feature.

 

[frutbunn]

Nothing in B Regs to prohibit it.

 

[RonnyRaygun]

Is there no requirement for a safe escape route to exit the building?

I wouldn't want to have to try to escape a fire in the middle of the night and potentially knock myself out climbing through a truss.

 

[^woody^]

I've not quite finished reading the B/regs back to Tudor times to allow me to quote them, but I've noticed that a typical statement is something like "xxxx shall be safe", and then the Approved Docs go on to give examples.

So there is some interpretation as to what would be safe, and a leap through the truss may well be acceptable - perhaps with suitable lighting?

 

[frutbunn]

I wouldn't want to have to try to escape a fire in the middle of the night and potentially knock myself out climbing through a truss.

You could use the same argument about the headroom height in a loft conversion which would effectively mean a rend to the majority of loft con versions and a csae to re introduce headroom heights into the B regs.
Ignore Woody he tends to conjure up non existant B regs. "So there is some interpretation as to what would be safe, and a leap through the truss may well be acceptable - perhaps with suitable lighting?"
Suitable lighting!! Had to laugh at that one, light switch next to the bed perhaps, is there a regulation to control the position of the bed, or maybe get the Secretary of State to introduce the provisions in the Building act for continuing control so a BCO has to tuck you into bed every night and make sure you have a torch under the pillow!

I've not quite finished reading the B/regs back to Tudor times to allow me to quote them

The fire of London 1666 were the catalyst for the first B regs in the UK in London, rest of the country it was the first building bylaws 1858.

 

[^woody^]

Get the truss taken out and put some steel purlins in. It seems that fruity has banged his head on too many trusses so should be a warning to your client.

Also don't believe that he laughed. He did not. He does not. He's always in the kitchen at parties.

 

[frutbunn]

He's always in the kitchen at parties.

Appalling bad music taste as well!

 

[^woody^]

Rude

 

[RonnyRaygun]

You could use the same argument about the headroom height in a loft conversion which would effectively mean a rend to the majority of loft con versions and a csae to re introduce headroom heights into the B regs.

Well, not really. Some loft conversions might have limited headroom I tend to think anything less than 2m is going to feel a bit oppressive, but it's unusual to find a loft conversion where a six foot tall person can't stand up. Furthermore, the issue here is that there is a triangular space through which anyone going to or from that bedroom will have to climb, over the strut and under the top chord.

Ignore Woody he tends to conjure up non existant B regs. "So there is some interpretation as to what would be safe, and a leap through the truss may well be acceptable - perhaps with suitable lighting?"
Suitable lighting!! Had to laugh at that one, light switch next to the bed perhaps, is there a regulation to control the position of the bed, or maybe get the Secretary of State to introduce the provisions in the Building act for continuing control so a BCO has to tuck you into bed every night and make sure you have a torch under the pillow!

Well...yes, but current regs are what I'm interested in here, as the loft space hasn't been a bedroom for the last 250 years!

 

[RonnyRaygun]

Get the truss taken out and put some steel purlins in.

Yes, that's what I would do, and that's what I have suggested to the architect. I can see it happening much further down the line when the floor and stairs are in and they suddenly realise what a PITA it is going to be from a practical point of view.
The architect who has picked up the project actually agrees with me, but this decision is client led (as all the best ones are )

 

[frutbunn]

Well, not really. Some loft conversions might have limited headroom I tend to think anything less than 2m is going to feel a bit oppressive, but it's unusual to find a loft conversion where a six foot tall person can't stand up. Furthermore, the issue here is that there is a triangular space through which anyone going to or from that bedroom will have to climb, over the strut and under the top chord.

Parts of the roof will be much lower towards the eaves, that's the point I was making.

Well...yes, but current regs are what I'm interested in here, as the loft space hasn't been a bedroom for the last 250 years!

How many storeys does the existing building have, if 2 or more storeys are the stairs enclosed and do they lead to a final exit.

 

[Tigercubrider]

If it's a 1700's cottage aren't there listing considerations?

 

[bernardgreen]

Nothing in B Regs to prohibit it.

Are you sure ? May be there is no specific ban in building regulation but the laws of statics do apply to roof structures. STATICS

When altering the construction of a roof be assured that gravity is NOT working in your favour.

 

[frutbunn]

Are you sure ? May be there is no specific ban in building regulation but the laws of statics do apply to roof structures. STATICS

I was only replying to the means of escape issues as raised by the OP, he's obviously already aware of the structural implications.

 

[RonnyRaygun]

Parts of the roof will be much lower towards the eaves, that's the point I was making.

Yes, but that isn't where the means of escape (doorway) would be.

How many storeys does the existing building have, if 2 or more storeys are the stairs enclosed and do they lead to a final exit.

The current property is two storeys, the loft will be a third storey.
The stairs are to be the space saver type. They are to be enclosed and they lead down onto the first floor landing, at which point, I assume, means of escape would be through the landing window.

The worst thing from my point of view is that the bottom chord of the truss is right in the way of where I want to put my steelwork!