Crew Quarters are arbitrary rooms for habitation and recreation of the Crew members on a Ship or Station. The more crew you want to have on your ship the more crew quarters you need, and if no sufficient space is provided, the morale of the crew will diminish continuously. Any ship and station has a base crew capacity of 4 by default and Crew Quarters is the only way to expand it. Crew capacity scales with volume so the larger the quarters the more crew it can accommodate. The material used does not affect the crew capacity.
Pre 2.0 you get 20/19 (about 1.052631…) crew members per 1000 m3 of crew quarters volume. Post 2.0 you get 10/19
The formula to calculate the crew capacity of a ship is:
<crew_capacity> = 4 + truncate(<total_volume_of_crew_quarters> * <crew_quarter_density>)
For cubes of each size:
|Edge (10m)||Volume (1000m3)||Crew|
This block has 2/3rds the mass and the same Durability as a normal block.