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

Depends on what stage you are at! Our architect presented us with a physical model along with a floor plan, right at the beginning of our design process. Without it, we would certainly have struggled to visualise the entire concept, and it definately cemented our faith early in the design. In the 4 months since, he has provided 2D renders of areas we've made minor changes to, and we are now waiting to view the 3D digital render, in order to layer & dress. He is also constructing a final physical model for us. We have an awesome architect!

Hi Sarah, hope you enjoyed your travels last night, that's something we have spent our lives doing plus living in different countries. Do look into the attic room/s they are lovely and the Velux skylights very unobtrusive, look great and if positioned correctly take care of venting any hot air, as I mentioned ours were pivoting ones and could be locked open in several positions. I much prefer these to dormer windows, you don't really notice them. The stairs were built off site and lifted into position and installed, built in. At the time we did ours a very good friend a builder did the same but just completely opened the whole ceiling space right out towards the gutters into a large bedroom play study area for his daughters, also using Velux windows. Glass ceilings, like Velux windows have been around for years, believe me I know, we're both getting older. Velux windows can be used as glass ceilings in opening and non opening configurations. I would love to see you keep the outdoor loo as well and updating the old shed into a new connecting space to the house, perhaps a glass breezeway. I will have another look at your plan again over the weekend. I love your front iron gate as well, auto sliding driveway gates work really well and would really fit with your carport. My brother in law put in a tall timber sliding gate at his last home, lovely cheers

Hi all, I can't seem to reply individually to your comments so here's a general one :) Thanks all for the suggestions and experience-I'm really intrigued by these suggestions of pavilion extensions, those links you attached Kate are super striking! Unfortunately for us we are on a fairly small block of land and one side of the house is a narrow driveway-we looked into building a garage/study on the ground but as we have to be 900mm from the neighbouring fence it was going to be very skinny and just not worth it. I appreciate the thoughts shared on keeping our feet on the ground but as we've two young kids and two dogs (and would love to have chickens again) I'm less and less inclined to give up more of the garden which is what we'd have to do if we extend out. Our verandah roof was done back in the 60's and slopes down and leaks in the rain so hence it needs to be lifted up if we were to build out. Kate, I LOVE your idea of the shed! We actually converted a massive steel shed into a gorgeous shed home when we lived in QLD on a massive rural block of land, loved how easy it was to 'knock' down a wall! :) Sadly we have learned the hard way that trying to save money by hiring a draftsperson that didn't ask us what our budget was has cost us time and money, but I guess in a way I'm grateful as this extra time has given me time to consider building up now instead of out. I'm getting a sense that it will be a lot more expensive to do so so might have to wait another 2-3 years to get re-finance happening. In the meantime we are making some changes to the current set up, slowly adding value and making it more enjoyable to live in :)