Due to my block being set down from the road our house is going to be built too low for gravity drain into sewer. I am happy to run all grey water (shower/washing machine etc.) into tank and use for gardens etc. But toilet is a problem, we have three options 1.) sewer pump, don't want the expense but more importantly don't want the ongoing maintenance 2.) two storey with no toilet downstairs, not my favourite idea as will mean guests heading upstairs for bathroom, 3.) split level with raised floor, all indications are this will cost an arm and a leg.
My idea is to elevate the bathroom/toilet area only, either by slab or just a wood floor with void to slab, does anyone know of a good way to overcome this problem or potential pitfalls for my suggested solution?