Hi Louise, I don't wish to pick a "bun fight" here however most times you can pick an energy/ design and cost disaster from doing a drive by believe it or not...there is more however....if we consider materials, effort, cost, design, energy etc you can design by numbers... I guess I was surprised at the aerial...the way I see it is its a complex roof and wall design when in fact one roof could do it all, you have how much land area?...and you build a 2 story house?....I don't see and trench's or bore holes for a ground source heat pumps, no PV, no solar hot water..to be fair its not finished....I guess the way I see it is as you say 2 modest incomes, can't afford a bigger hangar or hope to build a second one one day, 2 people plus dogs....I just expected something very different...I know nothing about international building codes, here however in Australia you can have your hangar and house in one...I mean why would you have a separate structure?...anyway its a wonderful thing to build your own place the way you want it and I'd never take that away from anyone. Me..I would have built one big hangar and a house in one end....120K water tank, stand alone PV, steel structure and straw bale infill, ground insulated, wind generator, biocycle septic, ground source heat pump, no energy bills, "less is more"....I should add I have been an electrical contractor for 30 years and worked on thousands of houses....99% of them are energy disasters that people pay for the rest of their lives, if you stood back and took a "completely unemotional" look from the outside and asked the question "is it fit for purpose"? did we maximise "all" aspects of energy efficiency, materials, costs and design?...I'll leave you to contemplate the measure, its non of my business...