The roof pond is constructed of fibreglass and fits over the main body of the building so that it becomes an extremely robust design; it holds up to 60 litres of water. The door can have a personalised motif; this mesh covered space is the ventilation for the dry toilet in combination with a ventilator behind the bucket. One side panel has a Blue Tit sized hole at the top and a bird box fitted inside. Only a spirit level: to get the base level; a spanner: to join the panels together; and a screwdriver, are needed for the construction. The internal fittings all slot into place and the unit is a “Seperatt” one. There is an additional seat for two-year-olds.

The overflow from the roof is directed under the floor and can be allowed to follow the urine into a soak-away or can be collected separately in a water butt and from there to a pond or bog garden. To save evaporation it is recommended to have some shade.