My advice as an Architectural draftsman would be to build as small as possible. All thermal and fire requirements are legislated in the building code and part of Basix requirements so eaves and insulation and water tanks are necessary.If you see windows without eaves around your area and its a new house then theres something else going on in the design, maybe the eaveless side is facing south and if it south it will never get sun so wont need eaves . Either way Basix is flexible and small design changes can influence thermal requirement outcomes dramatically. If it wont pass basix , try changing window sizes, amount of windows, or the amount of fall off and size of water tank, its very corruptable . A good idea would be to purchase a copy of "building your own home" and visiting this site
forum.homeone.com.au/just some things to keep in mind:
-Every Area is different from the next, what goes down in Sydney wont neccessarily be the samw thing for newcastle or QLD or Darwin so asking on this forum you're gonna get so much misinfo. Thats why people employ local architects or drafties coz they know the requirements right off the bat. employing non local designers will increase costs a bit if they are unfamiliar with your area as there is soooooo much BS to sift through each councils requirements.
-Higher ceilings= higher heating and cooling costs
-concrete floor= excellent thermal mass
-steel frames only can be used for one story buildings and still need termite inspection due to the rest of the house containing timber products.
- Timber framed houses last much longer in a fire, steel frames will buckle and melt much quicker.
-dont over insulate, it will work against you, but Basix will sort out minimum requirements according to design and climate conditions.
-Solar/ gas are the best and cost efficient water heating
-If you install solar panels for elec, build room for storage battery banks.
-Bathroom and kitchens are where you will spend most of your money so if you can keep them as small as possible the better.
- the house should be a highly functioning organism as well as keeping you dry and comfortable so get everything right
PS its only a personal opinion here but I think attached garages are a bit of a wank, I mean its like a bedroom for your car and is expensive too, the concrete alone needs to be a higher rating and usually garages are bigger than the master bedroom, for what? a car? carports are a very cheap and effective alternative. It can also depend where your building, most new estates have covenants that say you need to have an attached garage so all the houses can be somewhat congruent, but personally you'd never catch me out in one of those new manufactured suburbs with tiny streets where you can get fined for parking on your own grass. Put a massive steel shed out the back for half the cost.
PSS. I'd never build a new home.