Didn't think this was possible:

[Steve]

A house nearby - a 1940's semi - has had a 2 storey full depth extension on the side of it. Originally it had a pitched 3-sided tiled roof with no gables and two chimney breasts between the houses in the middle of the roof. Their attached neighbours still have. But this house, with its extended roof, now has a gable end, such that they could form a habitable loft space (it has a window in it).

I thought the 4 sides of a pitched roof "support" each other, leaning against one another, thus removing one side of it will cause its opposite side to fall over? And the whole roof would need to be restructured, wouldn't it? On the neighbours side as well?

I have to say also, that it does look a little odd, it would have looked better if the neighbours had the same roof.

 

[cumbrianroofer]

no this is not the case all thats required is a support for the perlin carrying the roof this could be simply joining another perlin onto the existing and bolting into place

 

[CortinaV8]

Just had plans approved for exactly what you describe, perfectly acceptable.

I agree with it looking a bit odd, however its the most effective use of the space and also for me anyway, the easier option to build.

 

[noseall]

We are currently building this exact scenario!

The bungalow is a 10m square affair with a bog standard ring purlin hipped roof.

We have gone out 4.8m on the back the full 10m width.

This 10m end is the gable end!!

Plus, the roof is a 40 degree pitch. I pitched the roof up on Wednesday using 7.2m long rafters. We needed a tower scaffold off the ceiling joists just to reach the ridge. The space within the roof is huge.

We will be building the gable starting Monday, into which the purlin steels will sit. These are 4.7m long heavy b***tards. Can't wait.