You are right, many just have the facade only. Which is crazy as its just a 'front', pun not indented......It all comes down to the costs involved.....$75k sounds a bit excessive to change the rest of the roof to match the front, considering the cheaper pitched rear roof area has costs involved which should be taken out from the quote......what was it including specifically? Have a chat with the designer about roof. Was it your own designer used or the reputable custom builder's designer. Some home builders tend have the designs and associated construction details and engineering drawings already drawn up hence the cheaper initial costs but excessive if you're wishing to amend the plans such as a full mansard roof rather than just to the facade. I'd shop around a bit more, not to get the whole house built cheaper but to get what you want to have, once completed. Good builders should be paid well but they shouldn't gouge the client.

Many solar installer recommend the degrees of latitude for you area as a starting point. In mid summer sun is 15° above the latitude, mid winter 15° below. Adelaide is 37°, so ballpark 22° for the mid winter lowest pitch. Good idea to speak to a few reputable suppliers/installers as well so as to determine which way they'll face, shading from tree's, etc. They used to say Northern side now they're saying West..... Northern or Western doesn't work at our place due to shading from tree's. So we will have to face them on to the North Eastern roof......

Thanks for your thoughts, they have helped us with our decision. We're now planning on using the barramundi roof tile (it's a grey, a bit softer than the soho nights black. And not so shiny) with matching gutter and fascia. And the cladding in paperbark. I was thinking cream windows instead of the timber, so there's some lighter colours on the brick downstairs to tie it to the top. We can't match it exactly to the paperbark cladding because we aren't using aluminium windows, but I'm hoping the cream (which is supposed to be more of an off-white with this manufacturer) will look okay in the clad dormers upstairs. Fingers crossed!

Contact Velux (skylights). Sounds odd perhaps but their installers are well experienced with water proofing, roof's, etc. or try a roof plumber experienced with terraces. Not just any roofer but one with terrace experience. I know a Velux installer and he makes up his own flashings, etc as well as being a great builder. Unfortunately he's no where near you.