Wdym, in terms of construction? Do you mean emissions from concrete, emissions from steel manufacture of rebar, environmental impacts of deforestation for wooden housing? As far as I understand it, there are a couple of thrown around solutions to that, like adobe, superadobe, rammed earth, cob, compressed earth blocks, and mixed concrete compressed earth blocks, going kind of order from what I've seen of hotter to colder climates, roughly. And none of those even really include the use of straight stone or wood, either. Surely, if you're moving away from cars, as is the MO of this sub, you need less huge bridges and shit, less superstructures, skyscrapers, and that also cuts down on the use of concrete and steel. Most of the reason why people don't like those materials is just as a result of higher labor costs, which is mostly as a result of them being unusual in the modern day, which means they'll remain unusual, because everything has to be minmaxxed to shit on this god damn rock.