The Lancaster Cohousing group have recently purchased land near Halton on the River Lune near Lancaster. They are intending to build a number of Passivhauses and a communal building. There are some existing industrial buildings on the site which may be improved and converted. This is likely to be an example of communal self build with very high ecological standards. There is a Guardian blog
Architects are ecoarc
Books
The two main books on cohousing are both excellent and well worth reading partly because of the range of examples they give on the continent and the US.
Cohousing: A Contemporary Approach to Housing Ourselves
The Cohousing Handbook: Building a Place for Community
The other book
The Senior Cohousing Handbook, 2nd Edition: A Community Approach to Independent Living
covers what is something of a relatively recent departure from the central idea of cohousing, i.e. a fairly balanced community.