Great care was taken in the planning of the observatory to try to ensure that temperature and condensation were kept under control.  This was particularly important because the observatory was based on a metal shed.  The walls were insulated to prevent the shed heating up and to inhibit condensation formation.  It was felt to be important that the observatory could cool down as quickly as possible at night, and thus the only insulation on the roof was a thin layer of polystyrene 'veneer' stuck to the underside of the roof with grab adhesive.  This will hopefully inhibit condensation formation yet still allow heat to be lost relatively rapidly through the thin metal roof..  A design of shed with a white roof was chosen to reflect light and heat off the roof during the day and hence stop the inside of the observatory from heating up too much.