littleniffer, that downstairs rumpus has access to ZERO windows. It will be dark & cave-like. I doubt it would be legal as I think all habitable rooms must have access to external ventilation & light (I may be wrong). Wouldn't be pleasant in any case. Although I don't like internal wetrooms without windows, I'd probably prefer that than a cave-like rumpus. If you've got enough land I'd suggest stretching the build or as far as possible along the east-west axis, increasing the length of the north & south facing walls, while decreasing the east & west facing walls. This should reduce the excavation required. Though the main benefit (along with better passive solar design) would be if you can get away with downstairs being only one room deep, then all rooms will have windows. I'd have an open staircase, not closed, so light can pass between each tread. Unusually, I'd try to locate the stairs on the north side of the house, & have the flights facing north & south, to increase light to the downstairs area.

my suggestions include having the bedroom entry door at the end near the wiw and ensuite for more flexibility for bedroom furniture arrangements, the toilet, vanity and door could be on the other side if the vanity wall cabinets interfere with a window and consider hinged doors for better privacy, sound and moisture proofing for the ens and also to have hooks on the back of both the wiw and ens for dressing gowns, coats, hats and dry clothesthe very generous shower could be substituted with a shower over a bath in this ensuite but i suggest that the big bathtub in the family bathroom will be much better than compromising the ensuite and it would be good to make your partner happy

Our house is full of cavity sliders. Twice they were all (but one) replaced due to swelling/warping and rubbing against framework when opening and closing. Some made terrible noise whenever we opened or closed them. Hubby had a hunch they were poorly manufactured overseas and discovered that was the case. Builder sourced a local manufacturer and the whole lot, bar one, was replaced and we haven't had any further issues. The one door couldn't be replaced due to it's location - a wall would have had to be pulled down, just as co-design has described. This experience makes me think it may be a case of ensuring you purchase well manufactured doors for your climate and particular environment, and take into careful consideration the particular location they will be installed.

Hi Deonne If your bathroom requires the two doors, my suggestion is NOT to have a bath. Keep it very clean and neat Across the recess have either a walk-in shower with a 600mm opening OR a glass panel and door. You may consider a seat in the shower ( example on our website ) A recess ( niche ) for shower 300mm high max length Wall hung, all drawer vanity. In-wall cistern toilet suite. Mixer diverter, overhead and handheld shower. Quality tapware, with min 10-year warranty Porcelain floor tiles min 300 x 300. Tile to ceiling, ( unless home has high ceiling, if high, tile to an architrave height ) min tile size 600 x 300, Ceramic to rein in cost