Extending with raised collar roof

[maidmarianne]

Hi, does anyone know if a raised collar roof makes adding an extension more expensive/tricky? We looked at a house that is far too small but has an enormous garden. We’d need to build a double height extension but the ceilings/roof upstairs are a bit unusual. The estate agent described it as a raised collar roof, I don’t know if that’s the correct term because Google is not showing images that look similar if I search for that! Basically the bottom of the roof externally ends a fair bit lower than the ceiling, so there’s a sloping section internally between the ceiling down to about picture rail height. I’m thinking this might make an extension more difficult, wouldn’t you need to build a completely new roof to be able to extend the upstairs?

Wouldn't make it significantly more tricky. Loft conversion might be, as you'd not be able to rest the beam on the wall unless you get a dog leg one made up, but for an extension you just brick the wall up a bit higher and leave the slope in the existing room. As with any extension you'd have to work out how to get the roof to work over the new part, but that isn't specific to raised tie roofs.

Oh that's interesting, thank you. I was actually assuming that we might end up having to get a loft conversion if we couldn't extend, it hadn't occurred to me that it was the opposite!
One of the neighbours has a more standard roof with a flat roof double height extension at the side. I guess that kind of cheap option is unworkable though?

Like I say I don't think it would be significantly harder. But a cheap flat roof double storey extension has challenges in terms of getting planning permission.
You'd be better to get some proper advice from someone who can see the situation.