[General] retain the economies of scale needed for the new metabolism

[nima_persian]

So perhaps something can be taken from the chaos and decentralized spontaneity embodied in shanties, and combined with the planned infrastructure of a designed eco-city. Cities built without extensive high rises can still be dense enough to make life without a car profitable., and they retain the economies of scale needed for the new metabolism built around efficient recycling of everything from sewage to sandwich wrappers.


I know what metabolism mean here. But I couldn't get the bold parts. Would you in a more simple way explain it?

 

[Tdol]

I can't see the bold parts,but an economy of scale means that it is cheaper and more efficient to do something on a large scale. So the writer says that even a new city that is not high rise could be designed for extensive/total recycling in such a way that it was more cost effective.

 

[probus]

"I can't see the bold parts". I agree; there are no bold parts from my point of view. The OP might want to repost.