Another key home upgrade: optimizing your heating, cooling and lighting to help counter rising energy costs. These purchases can help cut your bills:
LED bulbs. In January, new energy standards spark the phaseout of traditional 60-watt light bulbs (higher-watt models are already vanishing). LEDs are the best substitute; they use less juice than fluorescents and last up to 25 years.
Prices start at $10 but go as high as $50 for LEDs you can dim and fully enclose in a fixture. "The more features, the more expensive they are," says Mark Costigliola of the EarthLED online store.
The typical home has more than 40 light sockets, says the Energy Department, so installing LEDs could easily cost $1,000.
The savings: $3.80 in electricity per bulb per year, plus fewer replacements. You'd recoup the cost of an $18 Philips A19 11-watt LED, as bright as an old 60-watt, in four years.
A professional audit. While DIY energy audits are a good start, a pro's more exhaustive audit can save you 30% in annual energy costs, reports the nonprofit Alliance to Save Energy.
You can get a full analysis -- including a sophisticated test to pinpoint money-wasting air leaks -- for $500 to $700, says Dan Chiras, director of the Evergreen Institute green-building instruction firm. A contractor can seal leaks for around $300, he says. "That's the most important thing you can do."
A smart thermostat. Programmable thermostats can save as much as $180 a year in heating and cooling costs -- if you can figure out how to set them. The hassle-free choice is the Nest ($249 apiece). All you have to do is dial the temperature you like, and the units will learn your behavior in days. Installation costs up to $250 for the first unit, plus up to $50 for each additional one; adding new wiring could cost $100 to $300 more.
"This is the direction the technology is moving in," says Siobhan Spain of the nonprofit Center on Sustainable Communities.