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And lastly ventilation is probably of of the most tricky, it's very easy to create an energy efficient sealed box, but how do you create a healthy environmentASHRAE 62.1 and 62.2, "Ventilation for Acceptable Indoor Air Quality":
* https://www.ashrae.org/technical-resources/bookstore/standar...
> The answer is normally a complex HVAC system but that then uses power and requires maintenance.
> older buildings are drafty but it comes with health benefits and keeps the building dry by allowing moisture to escape.
Drafty buildings are bad. The air comes in through random cracks and crevices, which may have mold and which also allow bugs and rodents to enter. The rodents may leave droppings, which the flowing draft may then pick up particles from. There are no health benefits to that.
> The answer is normally a complex HVAC system but that then uses power and requires maintenance.
The drafty house you laud above will also use power: in the winter air that was heated will leak out, and the cold air that comes in will have to be brought up to temperature; in the summer the cooled air will escape and the hot (and perhaps humid) air will then need to dealt with to make the building comfortable. And that doesn't include dealing things in the air like dust and pollen (plus the above mentioned critters).
Or you can install some ducting to remove stale air from the house (esp. bathrooms and kitchens), and introduce fresh air (esp. to bedrooms) that is first filtered (MERV 13+) and then tempered via an ERV/HRV core so there's a minimum of re-conditioning needed. The main source of maintenance is the changing of the filter(s). And running an ERV/HRV will use less energy (W or BTU) than re-conditioning the leaky air.
This is a solved problem: build tight, ventilate right.
After air tightness throw on some insulation (while reducing thermal bridging) and you can have a house that uses minimal energy in dealing with environmentals. You just have to make the effort up-front when designing it (or when doing a renovation/retrofit).