BackyardBorrowed
http://www.backyardborrowed.com/Airbnb for Backyards
BackyardBorrowed is the Airbnb of backyards. Rent a cool backyard in your area to be used for a wedding, birthday, barbecue, or other event. Get third-party vendor quotes so you can focus on throwing your event.
Angel list: https://angel.co/company/backyardborrowed
Member count: 1-10