[marcus_holmes]

Less population density means more transport, though, as the city is so spread out. More cars, more roads, more parking, more infrastructure generally.

Smaller, denser cities are more walkable and have more room for parks.

Small, single-family buildings are incredibly energy-inefficient. Large 5-story apartment blocks are way more efficient.

I moved from Perth, Australia to Berlin, Germany - the difference is astounding. Living in Perth without a car was painful. Living in Berlin without a car is normal. The hot water heating is communal, even in some areas provided for entire city blocks, while every house in Perth has its own reverse-cycle air conditioning setup. High density living is just more efficient per person.