Efficient water heaters, boilers, and fixtures
If flow-limiting shower and sink heads cramp your style, that's fine. What's more important are the high-efficiency boilers and hot water heaters in the basement.
A tankless hot water heater, which switches on demand, can save up to $1,800 during its expected 20-year lifetime and reduce energy usage by at least 45 percent versus minimum building standards.
Energy Star boilers should use about 5 percent less energy than standard models, and furnaces should be up to 15 percent more efficient.
Jon Chase for The Boston Globe