Here’s how I see it…. if you are building/renovating a house and you are trying to:
a) build net-zero (primary energy) instead of the typical approach (climate-independent) of keeping utility bills to less than a few thousand dollars (meaning less insulation in warmer climates)
b) not trying to go (too) broke
c) you have good sun
then you have a few options:
1. passivhaus with PV
2. more typical superinsulated with PV
3. passive solar with woodstove and PV
4. active solar (perhaps not with even a woodstove) and PV. Done right, I suspect this active solar can be done on the cheap — the Yahoo Groups SolarHeat and SimplySolar and Gary’s builditsolar.com website have some smart people with some ideas. (One needs to be able to get through 5 days of clouds to have 97.5% solar fraction)
In the first two cases, there is some advantage to building a small house. In the latter two, less so, because if the solar thermal (heating & hot water) is sized appropriately, then who cares how big the house is! The sun is free!
From what I can tell so far (our 1-year experience), here are the problems with small/ish houses:
1. It might mean you are building/buying something a little weird or not typical. So if you are unsure how long you will be there, resale could be an issue untill we get to the point that people are generally drooling over superinsulated homes.
2. If you have little kids (and especially if you are in a cold climate and/or don’t live in cohousing with a big shared common house) you might go a little bonkers if you don’t have room to let them run around in circles.
3. Stuff. Junk. Accumulation. (And see #2 if you buy your kids too many useless toys)
4. A smaller sun-facing wall/roof means less room for solar panels.
So, if you are going to build small and have kids, there is some advantage (I think) to building on as few stories as possible. Ignore the “a cube has the least surface area” business. It’s not worth worrying about (too much) if you have kids. Don’t waste room with hallways. But try somehow to have a loop! Keep lots of rooms. Just make them smaller. Don’t be afraid to use point-source heating. We wimped out a bit and have 4-heads to our minisplit system (one per floor). But it would have worked fine with just 2 certainly. I still like a basement. Nice way to get the mechanicals out of above ground places with views. And room for a solar heated water tank.
That’s the view from here.
Do you have kids and live in a small/superinsulated house? Let me know how it’s going? Right now we have 8 people (4 kids under 6, 4 adults) living in what PHPP calls 1741 sqft TFA (treated floor area). And it’s fine. Beat that! Actually, I bet you could. As we built “up”. Do as I say, not as I do! 😉