Very well written, I think it will help a lot of people. Yes, factor in a lot of broken drill bits with renovating old hardwood! Even the concrete stumps were harder.

Many people make the same mistake that believing an architect will give them something special (or perhaps 'smart' as you noted). Wrong. Many say a draftsman will only design what you tell them. Wrong. Unfortunately the problem is with the poor choice by the homeowner. I've seen terrific work all designed by draftsman and absolutely poor work designed by architects. I've also seen rubbish by draftsman and stunning work by architects. But, is the final design the only reason of what the decision should be based? Absolutely not! No use having a great design that you can't afford to build or is difficult and frustrating to have approved by council amongst other things. It's like choosing any one to do specialist for you; can you talk with them easily about your ideas and not feel 'railroaded', do they give advice freely without feeling like they're not telling you the whole story, do they mention budgets, possible problems along the way, have they investigated site specific issues, etc..... Architects aren't greedy and just wanting more money, they provide a larger range of services that others don't. If you're a developer would you go to the local draftsman and tell him how to design a high-rise project for Melbourne's CBD..... of course not you'd go to an architect to look after the project for you. Just as you wouldn't go to a world renowned award winning architect to design a timber rear deck area that the local builder is going build.... Know what each professional provides and decide from there don't base it on a qualification only.

This may help you. http://www.architectureanddesign.com.au/features/product-in-focus/the-pros-and-cons-of-permanent-formwork-systems-fo We have not used the Zego system so I’m not able to give you any advice on it however we have used Dincell. I totally agree with the comments in the article about the advertising benefits of Dincel aren’t what we experienced as well. Dincel is a fantastic product but it does require significantly more preparation and attention to detail than they advertise to achieve a good result. Having said that, Dincel is a premium product that we will continue to use. Be careful with your choice of external finishes. Make sure that are compatible with the expansion and contraction of the Dincel. Zego may have an advantage here over dincel. Acrylic renders over polystyrene are time proven. Maybe I’m out of line, but I would be concerned about having a dark render colour on a sunny wall using Dincel.

OP, you should also consider energy efficiency & comfort. It's great that you appear to have north facing living areas (with a high proportion of glazing facing this direction). But looking at the elevation picture, it appears you may have too much glass. Overglazing can result in a home that becomes uncomfortably hot, even in winter! This is very dependent on your location & climate. Cooler climates need more exposed north facing glass, & exposed thermal mass (concrete or masonry) to absorb that solar radiation. Warmer climates require less exposed north facing glass & thermal mass, particularly hot humid climates, where exposed thermal mass can be very detrimental. In these climates it's important that northern glass is shaded, even in winter of glass areas are too high. As there's no floor plan, & you haven't mentioned your location, it's hard to tell if you've overglazed with exposed northern glass. Read the following site, & consider your glazing to floor area & glazing to mass ratios. http://yourhome.gov.au/passive-design/thermal-mass