Plumbing

As with mechanical systems, the main target is efficiency, or better effectiveness: delivering the water you want and removing the wastes you don’t with the least cost at current (and future) energy prices. Effectiveness comes at many points in the system: efficiency of pumps and motors, location, insulation and layout of pipes, and maintenance of components over time. It’s easy to find high-efficiency water heaters, but often easy to go a step further and configure solar pre-heating, or even capture of the heat in warm water draining out of sinks and tubs.

As the price of water rises everywhere (because fresh water is becoming inexorably more scarce), it will be increasingly smart to treat water like money: once it’s in your home, use it as carefully and often as you can before letting it go. That can mean something as simple as good low-flow showerheads, or as elaborate as rainwater harvesting from the roof or greywater capture systems.