Thanks guys, @Andy, I will be more than happy to keep everyone in the loop. Especially after everyone has contributed so generously. However, the reality is that we are in the very early stages of planning. Also, considering we are wanting to basically gut the house and renovate from top to bottom raising the funds will likely take time. Though I'm sure we will continue to return to this page and seek additional advise/suggestions moving forward. Oklouise, thanks for the floor plan. This will be very useful when showing a professional our/your ideas. A loft? That sounds expensive! Regarding changing from my beloved Hampton's style, we were thinking of keeping some elements from the original home. I.e the raked ceilings but white washing them. do you have an example of a modern mid century home? Siriuskey, ok you are making life way to hard for us now. You keep coming up with some fantastic ideas for the kitchen and my wife loves all of them! I agree with you about keeping those two front rooms. I think they are quite unique in the house BUT we really like Oklouise's floor plan which carves up that room into a WIP/study. Currently we are torn as we want to retain the room but love her floorpan. Life is just to hard! I do indeed like my barn doors! I think they are very cool indeed (not sure how quickly they will date), we were wanting to use one as the entrance to the WIP. I have attached another picture of an example kitchen style that I like.

Hi Lindel Love the design and view! There are a couple of solutions here, depending on what the requirements are (ie cost versus energy efficiency). To your original query, the Colorbond will give a better maintenance long term but obviously the energy efficiency is zilch. The structure behind needs to do the insulation work as well as be structural. From a cost point of view timber framing is cheaper but the wall insulation is limited. You can however use a structural insulated panel to be both the structure as well as the insulation for everything from the upper floor to the walls and roof.... We are doing an extension in this at present which will actually look like a 1930's character style to match the existing home. I'm not familiar with your BAL but we have found that when we get such high insulation ratings from the walls and roof it has usually enabled us to cover the losses from windows and given the ability to have larger windows without the need for double glazing. Regarding the timber, I would be considering an artificial product unless you want to do the maintenance. Cheers

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

Hi Bespoke Builders Ltd Thank you for your reply. I didn't consider trapped moisture under the baseplate and the builder didn't mention it. The plan with the previous builder was not sealing both sides exactly but running the silicone beads under the baseplate where I suppose it would have been squeezed out the sides and the excess trimmed off (so the net result would have been similar). Mould in the batts is a big concern for us. In this case the EPS cladding installers are using vertical battens to give a 25mm air-gap on the outside of the studwork. Also, the perimeter studwork will consist of 120mm studs with 90mm noggins and 90mm batts to give some internal air-gaps for the wiring. I'm based in South Perth. Do you have any experience with brick build ups/limestone retaining walls? If so, please see my other post < https://www.houzz.com.au/discussions/6291213/limestone-versus-double-brick-cavity-retaining-wall-to-support-slab > if you have time.