A mushroom house should be designed for the species and production method rather than copied from a generic room layout. Temperature, humidity and fresh-air requirements change through production stages.
Internal surfaces, racks and drainage should support cleaning and reduce places where contamination can persist. Water application should not create uncontrolled standing water.
Ventilation must provide the required fresh-air exchange while allowing humidity and temperature to remain manageable. In some climates this may be possible with simpler systems; in others more active environmental control may be needed.
For a quotation, define species, target scale, room dimensions or site area, local climate and the desired level of environmental automation.