They talk about the vast air temperature difference between this city and modern day cities being a result of using dirt roads/walkways as well as their focus on airflow by intentional tree planting.
The discussion continues to their communal living that includes water, bath houses, composting & security. There’s detailed commentary about their “remarkably simple” water system, which has been in effect for 200 years. It’s a combination of wooden aqueducts & stone pipes that carry water from the high mountains, through the farm lands & into the town proper.
Paul further discusses their “purely natural system” of repair, reuse, recycle > fuel.