An ecological house consumes much less energy than a normal house by meeting conditions like using small amounts of energy, being air-tight, and using natural and recycled materials. It can use 8 times less energy through technologies that minimize heat loss. Renewable energy systems like solar panels, windmills, and ground source heat pumps can be applied. The water problem in Poland is about chemical pollution of drinking water from a lack of adequate wastewater treatment and rainwater retention.