Community developments are often more cost-effective than individual developments and allow for shared use of space and resources.
Co-housing and eco-villages are similar in that they both address issues of affordability, ecological impact and community building.
There is a great article that defines co-housing here.
You can read more about eco-villages here.
Decided Co-housing is for You? Find CoHoMates here.
There are many community developments around the world.
In the UK, Ecomotive is a social enterprise supporting groups to set up their own community-led housing projects.
Opposite is a short (20 min) film that they recently made about Resilience through community in North America.
Below: Brookside Featherston Village, East Perspective