Wall plates different heights

[^woody^]

You've got something like a 450 set-back of the wall, so the new extension ridge should about 200mm lower, as per the approved drawing, so is there really a problem with the roof height?

In a planning context, it is the set back which is the crucial bit and which planners look for, and this in turn determines the ridge height. Its clear on the drawings and the planners have had the opportunity to study it, and in real terms they know what a 450mm set back will achieve. Fundamentally though, they have approved the drawings based on that set back.

BTW, the front canopy is incorrectly drawn on the extension, as the top of the canopy roof will be higher up the extension wall due to it being further back - unless you plan on forming a flat section at the abutment.

 

[23vc]

Thanks appreciate the reply and totally agree with all of it. The issue though, is that on the original house, it gives the illusion of the back wall plate being higher than the front, due to the front pier and overhang. The plan fails to show this, so it all works on the plan, but in reality the roof drop is MUCH less if I try to keep the same height of the new roof. I've done a new pic which hopefully explains better - it's quite possible that there's an easier alternative here but so far all I can think is different wall plate height! Basically the new roof needs to be the same pitch front and back, but a bit asymmetrical.

 

[23vc]

Think I've got a way forward which avoids dropping the wall plate - small cantilever on the truss , supplier is drawing them up now so fingers crossed

 

[^woody^]

Due to the pier at the front, you effectively have a smaller set back and higher ridge. The set back should have been measured from the main front wall, which would have moved the plate back, moved the front pitch back, and lowered the ridge.

So you are back to the coombed ceiling. I can't see what that canteleved truss will do as everything is related to the the ceiling height, and where that front wall meets the roof pitch

 

[23vc]

Hi woody
My current view is it will work, with my only compromise being a slightly lower ceiling. Both wall plates will be at the same level, ie dictated by the front side in order to get enough of a drop for the flashing from the verge above.
I'm still trying to get my head round it all but I do think it's workable and my easiest option . I'll report back here when I've fully got my head around whether it's going to work