Your designer should be able to advise of this to a certain extent. There are a thousand and one options though which makes it all confusing. Different manufacturers, suppliers, clients wanting/preferring certain manufacturers, etc.. An architect like Andrew Maynard (or many others) would be able to assist and 'bring it all together' or try a Melbourne based Hydronic Heating company and run from there.

Does using 19mm high performance glass make enough difference? What about using a system with frames to use double glazing? Sure it's not frameless but it'll make life a lot easier. What about a combination of different glazing systems from south to north? Or as noted before reduce the glazed area. Rather than full height drop the height down to reduce the area. I'd still change designers though because if this hasn't been considered until now what other hidden 'land mines' are there around to trip you up and lighten your wallet even further. A new (good) designer will go through the plans and assess what needs amending. Designing is complicated and complex and needs a lot of thought, planning and forward thinking.

The price is real ... Project builders can build for approx $850/m2 and sell most project homes for around $1000-$1050/m2 (base price!!!!). Where you will need to shell out more is when you look into things like :- The kitchen package (laminex benchtop & Carcass) could be $3000-$5000 price difference just in the benchtop; The external cladding could be cheap masonite or vinyl cladding system which will be outdated before you've moved in or you could be looking for something classy like James Hardie SCYON cladding (Stria, Linea, Axon) cladding systems - add $10,000 - $12,000; The tiles in bathrooms - could be $1.000 to $5,000 difference in prices here; The type & quality of timber flooring (if any), the type and quality of carpet could be cheap $3,200 carpet package for entire home or it could be $8,000 carpet with quality underlay which is LOW VOC (important if you have kids and love your family) or $18,000 for timber floor or it could be $45,000 for european parquet flooring throughout if you have an aversion to carpet because of allergies; The type & quality of PC items such as taps, toilets, vanity, shower rail / head, kitchen sink, towel rails right down to the toilet paper holder - there could be $5,000-$9,000 price difference here; The type and quality of main kitchen fittings such as cooktop, rangehood, oven (could be $900 package for an unknown brand or it could be $2,200 for something decent 600mm wide or $3,500 for something decent 900mm wide or it could be Miele and cost $5,000. Then if you look at the windows and sliding / stacker / bifold doors ... these could be cheap aluminium with 4mm float glass or you could be wanting 100mm x 50mm commercial aluminium with 6.38mm laminated tinted glass with low-e glass to all your western windows or you could be more interested in PVC windows with a steel internal frame with double glazing and blinds built into the double glazed unit with tilt and turn doors and windows - price difference is at least $10,000-$30,000; That's about 75% of the major decisions that you might want to investigate further. The biggest factor you'll be hit with is a little thing called 'site costs'. This is where project builders get to charge like wounded bulls. Any land that you find which is not 'dead level' will incur additional fees (counted in the thousands) and any soil classification which is not 'M' class substrata will incur additional fees. You may find an additional $40,000 - $200,000 slapped on for these charges and it will be disguised as "i'm so sorry but your land will need piers and footings and some serious excavation - there is nothing that we or any builder can do about it" Then if you want to upgrade the tap and kitchen sink you will find their pricing regime is out of this world. I built a single level home for a pharmacist and his family in north sydney back in 2011 and quoted $750,000 (it was a big home - almost 300m2) and the client got a bit edgy with me after months of discussions and decided to approach a few project builders after seeing advertisements for single level home packages starting from $370,000. After they had gotten part way through their enquiry process and had a site inspection and soil classification test carried out they were presented with a quote for $610,000 and that was without any of the travertine or double glazing or spray foam insulation or acoustic walls and home theatre systems that I had proposed. I think the shock of a project builder jumping from $370k to $610k overnight scared them more than my initial quote of $750k. We finished up at $830k after the lady had made all her decisions including $100,000 joinery (cabinetry for kitchen, laundry, custom vanities, walk in robes, built in robes, study) and $80,000 of Miele appliances (including $3,600 coffee machine) ... strangest part was SHE DIDN'T COOK. There was a massive bbq area with built-in bbq and wine fridge and indoor and outdoor fireplace and custom landscaping and the list went on. My point is, I believe you will get much more value - both immediate value for you and your family to enjoy when you move in AND resale value (people do appreciate quality and will pay for it) if you build with a proper builder and architect / designer who designs the size, style, external finishes and internal products to be how you want them and a quality that will last. If, however, you do not have the capacity to invest somewhere around $700k - $800k for this monstrous 52 square home you are looking at, but need the room to accommodate your family, then by all means investigate further with the project builder. I've been doing a touch typing course lately to help with my report writing and it has been quite interesting just rattling away at the keyboard without looking and giving you the best of my experience over the last 10 minutes. Hope it's of some benefit to you and your family. Best regards, Steve.

Trust me, no one wins when it gets legal except for the lawyers. It's truly not worth it. It's better to endeavour to put the energy into a solution, and sometimes the most effective solution is to consider a different option. Building and design ALWAYS involves compromise. Unfortunately you were led to believe that something you wanted could be possible that in reality was non viable. Whether it's a council restriction, or budget or whatever, a good design will negotiate the constraints to give you the best balance of solution.......the story you have here happens all the time in this industry...Yes the builder should have worked this out sooner, before signing you up, and you're unfortunately copping the bill.....I once had a client come to me (years ago btw) who had purchased some land (of the plan) on a new estate. When they went to see it half the site was hanging off 3m drop of land fill!! - not cool, and whilst the developer offered to "fill and level it up) it would have been a particularly expensive structural solution involved and understandably, but disappointedly they pulled out....... My advice is if you're not happy with a compromised design for your requirements walk away if you can, put it behind you and don't waste any further unnecessary energy and money on playing legal games. There will be another option out there for you, and better to start fresh with someone else because you there's clearly a loss of trust for this builder. So sorry to hear about this for you, my advice is don;t compromise on what you want, it's too large an investment, and also understand that you're not the only one who's had similar but different experience with expectations being severely comprised with house&land "deals" - we are dealing with a particularly rugged, uneven industry........Best of luck with resolving :)