I've been involved in trialling the new British Standard for sustainable filmmaking, BS 8909, that launched in Cannes this May (2011). The trials formed the basis of user-friendly case studies that are free from the British Standards Institution website. The standard itself costs £46 for members and £92 for non-members. 

Info: See here for press release, here for information about BS 8909 including how to buy it and free guidance notes.

Download case studies:

• Film development case study: Ealing Studios 
• Production case study: Greenshoot case study
• Distribution case study: Dogwoof - distributors of social films, and 
• Exhibition case study: the British Film Institute. The BFI is not only an exhibitor and archiver of film but is now the new lead body for film in the UK.