Several hygiene decisions are taken at the drawing stage. NHB's DPR asks for doors and ventilators screened with nylon net of 35 mesh or finer. It asks that spent compost go into a pit covered with at least 10 cm of manure so flies cannot breed.
It also describes an end of crop cook out at 70 °C for 12 hours, so the steam plant must be sized for it and the room must tolerate it.

