Hip to gable roof extension

[Believeitornot]

Has anyone done this on a semi detached house and any idea how much it might cost?

The loft has already been converted into a bedroom

The roofline has a slope which goes down to the end of the garage (kind of a "chalet type house), so one of our bedrooms has a sloped ceiling.

So a hip to gable extension would essentially provide a proper vertical wall all the way to ceiling for our bedroom plus give a flat wall for the loft room.

Does anyone have an idea of cost or issues to think about?

You may find the council won't give pp for an extension that big - they may want the extension to be set back from the original building line, often that is what us done on the first floor. Have a look locally at what sorts of extensions other houses have and find their plans on the council's planning applications pages online to see the drawings.

I can't really picture what you're describing. Is there a bedroom over the garage but in the hipped roof space?

This site suggests a hip to gable extension could cost £30-35k but I'd guess that assumes doing the whole loft conversion from scratch. So you may well find that just doing the roofing part of the job, as you'd need, could be a bit less.

Unless you're in a conservation area this falls under permitted development and doesn't require planning permission. Ours was 60k in London with two rear dormers to create two bedrooms and a bathroom.

You will likely find your existing conversion needs ripping out and starting afresh

Yep bedroom over the garage under the roofline.

We have a mix on our street - some extensions set back, some where they've adjusted the wall of the bedroom above the garage and some where they've effectively added a massive dormer on the side of the house.

I've been considering something similar to this, but not an extension exactly. It's only that our roof is going to need replacing sometime in the next few years anyway as there's loads of little things wrong that will only get worse. Getting the replacement done as gable rather than hip will just give us some extra storage space an let us increase the size of a bedroom but won't add any new rooms. I am hoping the differential between a a gable roof vs a like-for-like replacement won't be too huge.

I can't quite picture it still... Is it something like this?

Yes! Just like that

Cool ok! So do you want it like this with a hipped roof over the room above the garage? Or going all the way up with a gable end over that side (in which case you could have a pretty massive loft room)?

But do you already have gables at the front like the pic at 13:14?