I've been thinking about this as well VickiO. Extending a pitch V to a habitable space I've also seen referred to as getting a mansard roof. There are actually 2 houses on Nutfield that have them. One's more discreet than the other but I've not noticed them before I started out to look which must say something as I do tend to look around when I'm out and about. Good luck with your searches. Would be great if you let us know how the planning process goes. Lots of recent refusals for mansards on the southwark planning website which is disheartening but there is definitely precedent all over. One can only hope the right discreet respectful design would pass muster. Several of the refusals I read had not been in pre planning discussion.
