Insulation: Seek "greener" options for traditional insulation. For example, Bonded Logic's UltraTouch is just as effective as conventional insulation, but it's made from recycled cotton (mostly blue jeans).

Shower: A low-flow aerating shower head can save 16,000 gallons of water, which in turn saves 300 pounds of CO2 and $150 a year in water-heating costs. Also, a bath requires 30 to 50 gallons of water. In contrast, low-flow shower heads use about 10 gallons of water per shower, and even old shower heads don't use more than 20 gallons per shower.

Carpet: Look for carpet made from natural and organic materials. Be sure to look for carpet tiles, as opposed to wall-to-wall. That way, if a part of a carpet becomes worn or soiled, you can simply replace the tiles without throwing out the whole carpet.

Bedsheets: Bamboo bedsheets are softer than cotton, and bamboo doesn't require pesticides to grow. (Cotton uses 25 percent of the world's pesticides.) Cost: $27 to $70.

Dishwasher: Run the dishwasher only when it's full to save 100 pounds of CO2 and $40 a year. Running a full dishwasher uses 35 percent less water than washing by hand. If you forgo the drying cycle, subtract another 15 percent from the appliance's normal electricity use.

Appliances: Keep heat-generating appliances (even the dishwasher) away from the refrigerator.

Countertops: Granite countertops are not a renewable resource, and laminates often are filled with toxic chemicals. EnviroSlab is one of several companies that make "green" countertops from recycled glass and resin.

Furniture: Look for furniture made from wood that is certified as sustainable. The most widely used standard: the Forest Stewardship Council and its largest forest certifier, the Rainforest Alliance.

Heat: Change the furnace filter several times a year to save 350 pounds of CO2 a year. Upgrade to an Energy Star furnace to save 900 pounds of CO2 and $100 each year.

Water heater: Insulate the water heater to save 1,000 pounds of CO2 and $40 a year. Keep water at 120 degrees or less to save 550 pounds of CO2 and $30 a year. A solar water heater may cost around $3,500, but it will save an average of $90 and 2 tons of CO2 each year. With tax incentives available for solar water heaters, the system could pay for itself in about five years.

Shingles: Light-colored shingles absorb less heat and can save up to 10 percent on annual cooling costs.

Toilets: Low-flow toilets can save almost 30,000 gallons of water a year. Dual-flush models cost around $200, and single-flush models can be found for less than $100.

Unplug electronics: Even when they are turned off, electrical appliances still use power. Whenever possible, unplug electronics, especially cell phone chargers.

Solar panels: Solar hot water is so basic in Arizona that mass-market builders such as Pulte are beginning to offer solar water heaters in their homes. Rooftop units that generate their own electricity are starting to appear — and they'll be featured in the 2008 Parade of Homes — but they're a much dicier economic proposition. Contact your accountant or a solar store for information about the array of solar tax credits available. Tucson Electric Power Co. offers $2,000 to $3,000 incentives for homeowners who install solar generating capacity. See www.greenwatts.com for information about the program and useful links.

Thermostat: Set the thermostat 2 degrees warmer in summer and 2 degrees cooler in winter to save 2,000 pounds of CO2 and $98 a year.

Lawn mower: Use a push lawn mower to save 80 pounds of CO2 a year.

Floors: Many Tucson homeowners choose to go green indirectly — by buying durable materials for their homes, materials that won't need to be replaced anytime soon (and are frequently easier to care for than less-long-lasting products). Think stone and hardwood, not linoleum and carpets. Recyclable carpets are slowly entering the national market, but they're very expensive. Tucson's oldest neighborhoods are full of hardwood floors that are still going strong after a century. Wooden floors can be made from reclaimed wood (such as old barns) or new, sustainably grown trees. Engineered floors — made of a thin layer of hardwood laminated to layers of plywood — are unlikely to last as long, but they still outperform carpets and synthetic flooring.

CFLs: Replace three incandescent light bulbs with compact fluorescent lamps, known as CFLs, to save 300 pounds of CO2 and $60 per year. Warning: CFLs contain small amounts of mercury and should not be thrown away like incandescents. Burned-out CFLs can be returned to most hardware stores, which can dispose of them properly.

Laundry: Wash clothes in cold water, as opposed to hot or warm water, to save 500 pounds of CO2 a year. Also: A gas dryer emits about 40 percent fewer pounds of CO2 than an electric dryer.

Shade trees: Plant a shade tree on the sunny side of your house to eventually reduce your air-conditioning bill by 10 percent to 15 percent. And the tree can absorb a ton of CO2 over its lifetime.

Windows: Replace single-pane windows with double-pane ones to save 10,000 pounds of CO2 and $436 a year.

Windows and doors: Caulking and weatherstripping windows and doors can save 1,700 pounds of CO2 and $274 per year in heating costs.

Air conditioning: Change the air filter a few times a year to save 550 pounds of CO2 and $30 per year. Upgrade to an Energy Star air conditioner to save 1,000 pounds of CO2 and $60 a year.

Outdoor solar lighting: Yard or patio lights cost less than $20 and don't burn any electricity or produce any CO2.

Grills: Gas grills emit 5.6 pounds of CO2 per hour. In comparison, charcoal grills emit 11 pounds an hour; electric grills use the equivalent of 15 pounds of CO2 an hour. Solar grills have just hit the market.

• Tucson Interior designer Juliann Berens uses only "green" materials in the homes she works on. JB Interior Design Inc., 3958 E. Fort Lowell Road, 886-8932, www.jbinteriordesign.com.

• For environmentally sound building supplies and fixtures, Originate offers a wide range of new green and recycled materials, ranging from eco-conscious flooring to kitchen counters made from recycled glass.

Originate, 526 N. Ninth Ave., 792-4207, www.originatenbm.com.

• Industrial Chemicals of AZ, 5302 E. Pima St., 327-6331, is a good source for earth-friendly cleaning products, used by professional cleaners. The Maids of Tucson cleaning service advertises that it uses only environmentally benign cleaners. 795-7977; www.maidsoftucson.com.

• Some of Tucson's newest developments, such as the Mercado District of Menlo Park, no longer have recognizable yards; high-maintenance outdoor space has been replaced by communal barbecues and picnic areas, private outdoor courtyards and balconies, and the like. For the biggest builder of Menlo Park homes, located south of West Congress Street between Interstate 10 and Grande Avenue, see Street Scene Development at www.streetscenedev.com or call Jameson Leon Gray at 490-2404.

• If you do want a yard, you can choose to go green with native plants that don't require the irrigation that non-locals demand. At Pulte Homes' Sierra Morado, two classes of homes offer only xeriscaping maintained by the homeowners association. Sierra Morado encourages artificial lawns elsewhere (which may involve less-than-green materials but sure do save water). All plants in the Mercado District's 14-acre site come from within 25 miles of the neighborhood and are irrigated by a carefully designed system for using runoff. Sierra Morado, 10675 E. Bilby Road, 829-7019, www.pulte.com/sierramorado.

Gray water. The state of Arizona offers tax credits of up to $1,200 to builders and homeowners who install gray-water systems to recycle used bath and laundry water for irrigation. A basic gray-water system, including irrigation, can be added to a home under construction for about $4,000. A simple pump-and-hose system for an existing home should cost less than $100. For information and links to other water-conservation resources, go to www.watercasa.org.

• Rebecca Boren, Special to the Arizona Daily Star

• www.stopglobalwarming.org

• www.climatecrisis.net

• U.S. Department of Energy

• Madison Gas and Electric

• www.greenhomeguide.com

• www.treehugger.com

• www.energystar.gov

• www.Find-Solar.org

• Oak Ridge National Laboratory