@ambulastar1985 - The lack of insulation in Australian homes is indeed appalling. Coming from a European background where insulation standards are very strict (although they differ from one country to another), I fail to understand why Australia is so behind on that matter. We may not have much cold weather compared to Europe but our summers can be extremely hot and it's silly to rely solely on air-con to regulate temperature. So much energy (and money!) could be saved by just planning the house and insulating it properly to start with, without affecting much the initial cost or construction time frame. In France - which is definitely not a leader in environmental matters! - these days, when selling a house, you have to get an expert to estimate how energy efficient your home is and to indicate the energy rating on the ad and sale documents. Houses that are not energy efficient sell for less and can also be taxed at higher rates by councils. It's been a great incentive to get people to think twice when building and/or renovating.

Don't waste your money rendering the bricks - that look will go out of fashion. Don't replace your tiles with a colourbond roof either as that would be giving you an inferior roof and colourbond roofs are noisy. Replace your front door and try and choose wrought iron bannister railing. Then start off fresh with your front garden; soften it with magnolia shrubs, white agapanthus and trailing plants such as erigon to trail over brickwork in the driveway. Your bricks show a lot of character; please don't render them.

Hi Josie love that area! I used to live and work nearby..... Without knowing the budget or what you intend eg living there / going to make it a family home / investment property, there are quite a few options that depend on answers to the above. sticking with your original question, there are companies around that prefab the entire second storey that is installed in 1-2 days ( the structure install only- doesn't include roof prep etc) This includes the roof, finished walls (exterior and Gyprock internals). Your builder then needs to do the staircase, paint, finishes, bathroom fit off etc but it is very cost effective and is in the $1500m2 range. you obviously need to renovate the existing but $2500m2 is a good guide as others have said.... It really depends on your taste and again, whether it is a home for you or an investment. I understand the detonate thinking, however the existing layout can be worked with. Before detonating, it would be smart to speak to the Council about your setbacks etc of the existing home as quite often the existing home is closer to the boundary than what a new home could be. For a quick and dirty answer to replacement cost for a new double storey home, speaking to a double storey project builder with standard designs will allow you to see what works without a lot of expense as they can advise if their designs will fit. This will give you a budget and allow you to see some designs. you may even see some ideas you like and with which a designer can build on (no pun intended ) cheers

My $0.02 - in NSW designers are NOT registered or accredited, beware. All architects are nationally accredited. I suggest that there are a lot of things you can do yourself before you start - get a proper survey of your block, ensure that you get them to provide angles for anything that isn't square....understand if there are utilities like sewer pipes which will affect your setbacks or useable space...... Go online and workout the sun angles for your longitude and latitude helpful for solar and overall layouts. West facing picture windows are not the best. Some of the solar firms have online calculators which help to do this. Read the local council rules and understand them, apply them to your survey and your design ideas....including if you are a corner block and if you want to go two storey...... If it is still a 'go' Get all of the heritage, flood, fire etc checks done by council - around $150 depending on council........ Eliminate or at least understand all the big constraints before you go any further........ Look again at the survey- any contour lines may cost you money, assume a cost of at least $2000 per sqm to start and do some layouts of your ideas on paper, add up all of the spaces, can you actually put them on your block? How much is the total?.......yes garages are slightly cheaper to build but still take up precious footprint space.... Is access likely to cause issues for trades, equipment and deliveries?......... Keep refining and updating the ideas and plans thinking about how you want to use the spaces and move around inside and out.....where are you putting the wheelie bins, clothes dryer etc..... Try the free to use BASIX site forms if you are in NSW, understand how the size, shading and orientation of windows affects your sustainability and adjust, this will also apply many of the local council rules as well..... Do you want a brick house, with render? A pole home, a kit build? A fast build insulated panel build? What type of roof?...... The more you have worked out for yourself the better, look at the kit home options, there are lots and some are very good... Everything is delivered and you just construct with the trades and some may have builders in your area.....The new InsulLiving Code Mark BCA approved options are also worth a look..... Anyway do all of that before you line up for the fleecing floor lol