Appreciate the thoughts and this may be a solid option elsewhere in the country but in my circumstances I don't plan to be moving from this property any time before the kids are 18. It is located in Sydney's inner west, and in a specific high school catchment I plan to take advantage of when the kids are older. Stamp duty to buy the property was close to $100k and if moving out even in ten years to a larger property; that averages $10k a year spent on stamp duty. I know 115m2 internal is tight, as is the fixed layout due to existing bedroom walls, ceiling heights, wet areas, and the like - but there has to be a way to make this work... I have read that 4 bedroom apartments should be 102m2 or bigger. I am willing to make compromises where possible but I really want to create that extra separate room "Multi-purpose room" which can double as a study/work area/kids play area/media room/ad-hoc sleeping accommodation". Paul Di Stefano: I don't think these changes essentially equate to 'rearranging a sock drawer' - this is my PPOR so I am not too concerned what other buyers want or resale value if I plan to hold the property for 10-20 years +... (any trends we design for now may well be outdated by then anyway). Many buyers highly value indoor-outdoor integration. By moving the kitchen to centre, it opens up the rear and creates indoor living->outdoor living link. If I get IKEA flatpack kitchen and DIY as much as possible - have a friend reroute the water/drainage/+his licenced electrical friend...hopefully this work would cost sub-$20k. Adding the sliding door to rear is $2.5k. Ensuite, bathroom and laundry I believe I can fitout for $10-15k all up- let's say 15k (again, tiling, raise flooring, showers/fixtures/flat pack laudnry cabinetry install all done in-house without tradies). The only thing I really need professionals for is to move the gas line in kitchen, BIR installs, stone benchtop, and maybe a few adhoc wall demo/construction/doorway moving - lets call that 10k. All up ballpark that is 47.5k? Sirius- If I go with your style plan then I lose the potential 4th bed space and have no where for relatives to stay, babysitter, nanny; etc :( Maybe it is a possibility that the main living space be used for lounge room and kitchen, we can always put dining table in the Multi-purpose room, then when that room is needed for sleeping accommodation, the dining table be moved to the side and kids can eat dinner on island bench bar; lounge or outside table... ? those doors to each side of the fireplace as you suggest - this space is very cramped outside (2.45m width) and potentially would be used to store trailer or garden shed, there is an old terrace built on zero-boundary there and they have a DA to go 2 storeys; which will shadow the whole area. This is why I planned to make the rear south corner a raised deck and try to channel house activity leading out the existing glass french door to that deck, or the rear sliding door. See photo-(my house is on the left, terrace zero boundary on right, and front on is a wooden dividing fence which on the opposite side is the driveway/1 car park and front street.

thank you for all of your comments. The main issue is that this wall faces quite a steep hill, so if I excavate too much I run the risk of creating a 'pool' under a suspended floor, facing the hill. This would be a disaster for the old double-brick home, which already has damp problems from water from the hill. My other concern about a slab is creating a permanent damp patch next to the house, assuming the black plastic membrane under a slab would be permanently damp (no evaporation). The mortar throughout the original house is lime mortar which is highly permeable and turns to dust when permanently damp John Cameron, I appreciate you mentioning passive solar, I'm familiar with this. Would it be best in this case to put rigid foam (say 50mm) under the actual slab before casting it? There will still be a thermal bridge at the perimeters though. MB Design I like the idea of a graded slope under a suspended timber floor, so will check with a structural engineer as to 150->400 allowance, noting my comment above about not wanting to pond water Two's Company I like the idea of a cement sheet for the wet room area - I have actually done a bathroom like this before and it works with great waterproofing. TBH I'm wondering right now if I should just redesign the whole thing. I'm going to make another post to canvas opinions on the two options and costs. Thank you! Sue

Please clarify as to what is the actual problem with your hardwood floors, being in the front of dishwasher?

I've been looking for reviews for Heartridge and couldn't find any either, so hard to choose them without that information!