Like blanketing the tank, wrapping insulation around hot-water pipes reduces standby losses. Water arrives at the tap 2 to 4 degrees warmer, which means you won’t have to wait as long for it to heat up, thus saving energy, water, and money.

While this isn’t an expensive DIY job—6-foot-long, self-sealing sleeves ($2.50) easily slip over pipes—it could take effort, depending on where your hot water pipes are located. Exposed pipes in the basement are an easy target: hard-to-reach pipes in crawl spaces or walls might not be worth the trouble.