@gerard stewart - slab was ~60-70k & roof was ~20k. Overall happy with the project... we ended up spending a lot more than planned and it took almost 2 years. If I had to do the project over, I'd spend a lot more upfront with an architect, planner or designer. We ended up spending alot of money and only ~2k on drafting/design for council approval. I've spent hundreds of hours researching products and doing drawings (3d modelled the whole property) and although its (mostly) been fun - professional help at the planning/design phase would have saved my time/money and delivered a better product. Really happy with the concrete slab - has been zero maintenance so far. With post some photos tomorrow.

it looks like pebbles attached to the surface?? if so and there are no major cracks in the base concrete it may be possible to refinish the surface without replacing the whole lot...discuss with a driveway specialist (your builder may be able to make a recommendation)

Thanks @User – what you've said makes sense. Here's another picture of our driveway at present: http://tiny.cc/4qjytz Whatever option we go with, we'll be improving the underlying base (excavating some of what's there, re-laying, grading and compacting). As part of this we will be improving the drainage (either having a crown in the driveway, or having a slope from the right to left). But drainage is one thing, material is another... The stabilised decomposed granite option is a bit more affordable than coloured bitumen, and the landscaper who offers it can upgrade our edging and stone retaining wall as part of the job. However, I've heard really mixed things about stabilised decomposed granite – some say it gets quite hard when stabilised well and can last 7+ years until more maintenance/resurfacing is required; others say that even when stabilised it goes muddy when wet and brings dust/fines into the house, especially the red granite variant. Coloured bitumen (using an emulsion, different to cutback bitumen) is more expensive but I'd be happy to go down this path if I knew that the surface aggregate/coloured rocks wouldn't erode in the first few years – some local (non-sloped) driveways I've seen with coloured bitumen seem to have some loose material. I am hoping for some insights into either of these options

hi kate, i have got this reply from the engineers. Now builder will give me some suggestions for portico without piers. so still house will be push back half meter and fecade will change no piers. If still you can give me some suggestions will be greatfull please Check the reply from engineer bottom of the image. " Please see below comments from the engineer. Please let me know how you wish to proceed. As per the attached preliminary site plan and photos, the site has a steep embankment at the front. There is a portico alongside the driveway (you cannot have the driveway higher than the portico) there is only approx. 3m to 4m of driveway that can be graded. The maximum driveway grade allowed is 1 in 5 (20%) in the ramp between transitions of 2m long at 1 in 10 (10%) both at the start and at the end. This does not leave any ramp length and the driveway can only grade down 400mm over 4m. The site will need to be filled 400-500mm and the existing retaining wall to the right will not be high enough. Also a retaining wall will be required to the front. I suggest moving the house back 1.3m so there can be a ramp in the driveway and existing site levels/retaining walls can remain close to what they are. (some fill may still be required) Alternatively remove/reduce to portico and setback the house less"