The proposed Thames Gateway "eco-region" would redevelop existing homes and reduce their carbon emissions by 60 percent, while making new homes carbon neutral. As for water, the UK's Environment Agency announced that the whole area (new and existing houses) could be water neutral, requiring no more water than is currently used. To do this, water-saving appliances, low-flow showerheads and low-flow faucets would be installed in both new and existing homes.

A Florida homebuilder is also aiming for water-neutral building, using similar showerheads, toilets that consume less water. The house will also reclaim its graywater from the bathtubs, sinks and clothes washer, which will return it to toilets for flushing and water the house's green roof.

These homes still use water, but the builders are taking the necessary steps to conserve as much as possible.