Hi Yvonne K, 6 months ago my husband & I moved into a dual occupancy with my sister & nephew. It’s a two story house with my sister upstairs & my husband & I downstairs. We each have our own front doors & car parking, the only thing we share is the backyard & pool area. Having lived in units previously, this is not an issue. It was my sisters idea, because we were both looking for a new house at the same time, she suggested that we pool our finances & get something better. While not multigenerational it is family & so far it’s working out really well. Good luck with your joint venture, I’m sure with some careful planning yours will be just as successful

Good to hear this has triggered review........re the basement costs, it depends upon how it's done. Either way you are doing 2 other separate garages that would be rolled into one. it involves negotiating levels, grading driveway at the higher end to get down so there could be some increased complexity.....but it's hard to make an accurate comment on numbers...... Catherine when you are doing something of this scale it's critical you are working with people/designers who are ALL OVER the costs in relation to design decisions and options. If they can't provide you with this advice and it's just design/plans/drawings that then get handed back to you to discuss potential costs with a builder, then I'd argue they're not up to the task. Before we do anything we robustly thrash out just numbers and project scope relationships (ie no detailed drawing!) and it deals effectively with the major issues and project alignments at the right time, and mitigates the nasty surprises or wasting resource pursuing options that are not viable. Either way, as I previously commented, as it's drawn currently it's a relatively expensive design that is arguably not delivering you the value/potential that you'd expect for an expensive design if you get what I'm saying. You will be paying a certain amount for a split, staggered or two level building (which is essentially two residences in one) and when you're getting into this type of construction ( basement or garages + driveway with a building of certain complexity & size) it will pretty much cost a similar ballpark whichever way you configure it.........BUT the outcome with be DRAMATICALLY different one way or the other, comparing designs of different levels of quality. Good design is not necessarily more expensive, rather it is better considered and gives you more for your money.

@dreamer thanks for your input. Do you mean placing glass sliders nstead of highlights for bed 1 and bed 2? Do you think that would be OK close to boundary? Also where would you place them for furniture placement? What type of door for bathroom privacy? A swing door? Do you agree with @kate to narrow the peninsula bench? Yes, this will be a rental for all ages. We have a very good highschool across the road and many, many.people move into the suburb to be in the catchment for the school. Eventually my parents may live here but that would not be for at least 10 years or so. What do you think of laundry space? I will need to check whether or not you are allowed to do this. Storage and porch areas do not count for internal floor space max at 70m2

is the garage attached and part of the original house or a separate building or extension?...we need to see a site plan showing all buildings and a plan of the whole house showing room sizes, doors, garage doors, windows and location of existing plumbing.. ..what is the shape of the whole roof (Google earth view and some photos would help) and what are the roof, walls and floor (of the house and the garage) built out of?...is the garage at a different floor and/or ceiling level than the house, how will you use existing bedrooms and do you need a new carport/garage? BUT before you make too many plans you should check with local council to clarify what will be needed for the conversion because a garage is not usually built to be suitable for bedrooms or living areas and 10m x 4m is probably big enough for 2 beds and a bath or 2 beds and a small living area but not for 2 beds + bath + living area