Michelle, I'm not a builder but am building with hubby, a single storey limestone home. Our daughter built a two storey limestone home just down the road, that hubby also built for her and the extra foundations she had to install would be at least twice more than we have for our single storey, not to mention that there were allot of short walled founds leading off the perimeter of her home to assist in less likelihood of wall roll out and the inspector called it. Cost for you, will depend on whether you have adequate foundations to carry a second storey and usually that is never the case. All the lower walls will need double the support and it usually has to carry on down to the foundations, depending on whether you have a solid concrete slab or concrete stumps that are accessible. This would mean most of the plaster being removed and hoping that you find no nasty surprises as far as the condition of the existing frame in the home, the builder would as I mentioned, have to add structural supports to carry the second storey. Most often, second stories are built with a hardiplank type exterior and certainly not brickwork as you would then difinitely have to have extra foundations in for such a reno and you would have to start asking yourself if it isn't better to demolish as this type of reno can be extremely costly. You might be lucky but probably highly unlikely, to have adequate structional integrity to be able to add a second storey, without everything I have mentioned to be skipped in any way. I hazzard a guess that such a reno would cost you $250,000+ and maybe more. Would love to know what you finally decide to do and your builders estimate. Good luck. Cheers, Barbara

correct measurements are the only answer...for your new floorplan you need a room (without any restrictions that would measure at least 2400mm x 2000...it's always possible to squeeze in some minor variations but only if it's worth the cost in convenience, improved value of the property and actual cash outlay.... the front door entry foyer would be lost, the new bathroom doorway wastes more space, the linen cupboards would be too narrow for anything except a few towels and sheets (that can easily be stored in a suitable vanity or bedroom cupboard) the bathtub is gone and you would have spent about $20,000 for a bathroom that is not better than what's already there?? ...the computer programs that we use are called 3D Home Architect and my version 4 is no longer available to buy but i believe siriuskey may have purchased her version recently? these programs do make the plans much easier to see but you must start with accurate measurements and an understanding of spaces needed ...start with a space about 800 x 800 mm for a toilet, 900 x 900mm for a basic shower, 500 x 900 for a single handbasin 1500 x 500 for a double handbasin then add in at least 900 x 900 for a doorway (including space for the frame and space to walk through...same for cavity sliders!) and then you'll need space to walk around in front of the toilet and shower and handbasins ......unfortunately with the plumbing and space restrictions i don't believe it's possible to do more than widen the existing shower space by rearranging the entry wall.(NB you'll still need to spend $5000 to $10,000 for demolition, carpentry, new waterproofing, tiles, shower, vanities wall cabinet, taps, plumbing etc..forget the linen cabinet and store linen in a new vanity and toiletries in a wall hung mirror doored cabinet and keep some width in the entry foyer (minimu 1200 wide) ...removing some of the non structural wall in the kitchen should be the cheapest improvement for the kitchen and add space for a small breakfast bar but removing the end counter would lose valuable counter space that could also be used for a pantry ...before making any decision you need to think about the reason for the changes...are the bathroom, laundry and kitchen in need of immediate repair, is the unit for your own use of needing improvements for rental or resale...?? always happy to draw up your plans but have to nag again about the accurate measurements...try measuring each separate room (ie shower, toilet and vanity, laundry and storage from wall to opposite wall in several places in both directions, ignoring all the fittings but include separate measurement of the diameter of the hot water heater.

with 22m to the rear boundary my suggestion would be to build a separate dwelling using a variation of the house plans on the yourhome.gov.au website and connect the two building with an extension of the existing covered deck to make a shared alfresco...the new building would have a raked ceiling with the roof sloping down from north to south.. the web site has detailed plans and specs suitable for Adelaide that a builder could use to estimate costs eg 150sqm @ say $2000-$3000 per sqm depending on materials and quality of finish and contingencies but you'll need to discuss your ideas with council as there's also a restriction on the total area of the block that can be covered with buildings but something like this could work with the mancave extended from the carport but you also need to ensure enough light and view into the family dining and kitchen

what is the hallway marked .59 and your plan shows bed 2 opening off the master bedroom...it would help to be able to see the whole house plans before attempting an extra bathroom