If you work for a big operator then the pilots union would set the standards for accommodation but normally all operators would want to ensure that their flight crews receive sufficient rest in interest of safety and productivity.
You could email Ifalpa.org or ECA
https://www.eurocockpit.be/ and I´m sure they would assist you with minimum standards.
If hotel or house accomodation is not available nearby your base i.e. camp operations then normally crews negotiate a certain reimbursement for living in tent. In Europe that amount should be equal to price of hotel room or thereabout. At the very least it should not be a cheaper solution to let crews sleep in tents. The tent has to be of a certain standard also.
The APA (American pilots association) in a NPRM to FAA duty & flight time requirements set forth the following definition for hotel rooms:
"APA recommended the following revised definition: “suitable accommodation means a single-occupancy hotel room or equivalent with a bed, sound mitigation and light and temperature controls that is reasonably free from disturbances.”
http://www.faa.gov/regulations_polic...-FinalRule.pdf