The growing demand for intelligent water recovery and filtration systems for all areas of life can only be satisfied by efficient, environmentally friendly technologies. Until now, 30% of the total available drinking water in an aircraft has typically been used for flushing the toilets and added to that are transportation and installation costs. Modern and sustainable technologies can offer improvements concerning these aspects in all areas and can drastically reduce CO2 pollution. Lavatories installed in passenger aircraft should show the smallest possible CO2 footprint in the future. The new Greywater reuse unit uses drain water, filters and stores the regained water to flush the toilet. First of all, this process reduces the required amount of drinking water by 250 kg (using a Boeing 787 as a reference). Additionally, it generates savings in CO2 emissions of about 550 metric tons per year, per aircraft. The operating costs of the aircraft operator are reduced and the feeling of hygiene is noticeably improved, along with a more comfortable flight experience for the passengers.