A billionaire has rebuilt downtown Detroit

Rebuilding the rennaissance centre offers amazing possibilities. On a personal level I prefer low rise cities, noting that sprawl is also crap. So maybe the answer for Detroit is "just enough" density, and high-rise in a central business district, but otherwise.. less.

Reclaiming waterfront as a commons is a big thing.

There is an entertaining childs book called "unbuilding" by David Macaulay, 1980. It makes me think, as does a chapter in the otherwise rather awful pot boiler "warday" by Whitley Strieber and James Kunetka. There is so much value inherent in the construction materials in a modern building. Miles and miles of copper, Aluminium, steel, tiles, sinks, toilets, you-name-it. They're giant warehouses of potential re-use.

John McCarthy (LISP) used to say on USENET forums about waste that future generations will thank us for burying all these amazing inputs in the ground in waste tips, ripe for the picking. The cost to sort and grade and extract things may be less than the energy inputs to make them from scratch.

I always thought if I had that kind of money I'd setup a bunch of hacker houses there.