Lavatory

The Lavatory is a water-based toilet building that gives Duplicants a place to relieve themselves while reducing disease spread. It is the standard upgrade from the Outhouse, since it is more hygienic and does not require manual emptying. It also transmits fewer germs to a Duplicant’s skin, making it a better choice for stable bathroom setups.

Besides its basic sanitation role, the Lavatory satisfies the toilet requirement for a Washroom and provides +2 Morale. It also counts toward room requirements for certain facilities, including Public Bathrooms and Infirmaries, and it is a required building for a proper Bathroom. Because it needs no maintenance once supplied, it is especially useful in busy colonies where keeping toilets serviced would otherwise be inconvenient.

Mechanically, the Lavatory consumes 5 kg of Water and produces 11.7 kg of Polluted Water through pipes. The output is a mix of the input water’s temperature and 6.7 kg of newly created 37°C Polluted Water, so repeated use will gradually push a Bathroom Loop toward 37°C. The extra output means the building can be used as a tiny net water source when paired with a Water Sieve, but the gain is small: one Duplicant with a normal bladder produces only about 11.16 g/s of net water or polluted water, and keeping an Electrolyzer running nonstop from this alone would require about 52 Duplicants using the bathroom every cycle, or 90 if the bathroom also relies on the toilets’ output.

The output is not clean. Each use generates 105,000 Food Poisoning germs, divided between the Duplicant, the Polluted Water, and the Lavatory itself. The polluted water carries the vast majority of those germs, so refining it back into the main water supply without treatment is a bad idea; Water Sieves do not remove germs. If the output is being reclaimed, it must be disinfected first.

• Use Lavatories to replace Outhouses as soon as plumbing is available.
• Match the number of wash stations to the number of toilets when possible, so all Duplicants can wash their hands instead of skipping the sink when everything is occupied.
• Scheduling can help by reducing how many Duplicants use the washroom at the same time.
• Because the output is always 37°C, the Lavatory can also act as a small heat equalizer in plumbing loops.
• Any reclaimed polluted water should be treated as germy wastewater, not as clean supply.