Erin Hasinger traded in her SUV for a Mazda 3 that gets 24 miles per gallon in the city, 32 on the highway, and drives it from her home in Gibsonia to Duquesne University, where she attends graduate school and drops off her cardboard for recycling.

In Washington, Pa., Nancy and Rod Weiss bought $20 carbon offset credits when they flew to visit their grown daughter in Austin, Texas, and are considering installing solar panels when they replace the slate roof on their 104-year-old home.

Erin McClymonds hangs her wash -- mostly little-boy T-shirts, pants and pajamas -- from a clothes line strung across the back deck of her big home on a Cranberry cul-de-sac. It's a violation of her neighborhood's homeowner covenants to hang clothes outside to dry, but these days those shirts, pants and PJs waving in the breeze are just more flags signaling the gradual greening of American lives and lifestyles.

Like a tree in spring, the environmental ethos, knowledge, actions and activities of many in the Pittsburgh region are leafing out and "going green." More and more, individuals and families are taking the environment into consideration when they do their grocery shopping, build or renovate their homes, buy a car, plant a garden and do a hundred other everyday things.

This story profiles three families who said they were already on the road to "going green" and wanted to find out how to go greener. Each was interviewed about what steps they've taken and what plans they have to do more. Conservation Consultants Inc., a South Side non-profit organization that has done 50,000 home energy assessments since 1978, provided an energy auditor to do a home inspection and suggest ways these families could further limit their environmental footprint.

The profiles:

On a recent weekday afternoon in the McClymonds' 13-year-old home, twin 3-year-olds Liam and Lachlan, their 10-month-old brother Quinn and two big yellow labs, Roxy and Riley, are running around, jumping on and off furniture and pumping out enough loud energy to create their own weather system or maybe power the 3,000-plus square foot house, if only they could harness it.

As the boys and dogs tumble around, Mrs. McClymonds details the green steps she's taken since the family moved into their home two years ago. They added attic insulation, installed two attic fans, recaulked around their double-pane windows, put ceiling fans in all the bedrooms, hung screen doors on two back doors and a heater blanket around the hot water heater. They have a plasma television in the living room, which uses slightly more electricity than an LCD -- liquid-crystal display -- television.

"We're not totally green and it's really selfish on our part," Mrs. McClymonds said. "When we moved to the bigger house I wanted to save money by saving energy and I want to make my children's lives safer."

Some of the behavioral changes have been harder, she said, but they buy organic milk and some organic foods and don't water their lawn. They've minimized use of the whole-house air conditioning, use only cold water to wash clothes and regularly hang their clothes on lines strung across the back deck. A vegetable garden is still in the planning stage, maybe for next summer. She drives a 2006 Honda Odyssey with a six-cylinder engine that can run on four cylinders on the highway.

"I don't think there are any hybrid minivans but this gets the best gas mileage of all the minivans we looked at," Mrs. McClymonds said. "I can't get three car seats and the dogs in a small car, so I'm stuck."

As old light bulbs go bad, the McClymonds have replaced most incandescent bulbs with the much more energy-efficient compact fluorescent bulbs.

"The rule of thumb is to replace incandescents with CFLs for any light you have on more than two hours a day," said Jonathan Nadle, a certified building analyst who performs audits for CCI. "They're 75 percent more efficient, last longer and produce a lot less heat than regular light bulbs. And lighting can account for 15 percent of your total electric bill."

The McClymonds' electric bill is $225 a month and their gas bills are approximately $200 a month. Mrs. McClymonds said they keep the thermostat at 68 degrees in the winter because of the kids. Mr. Nadle's inspection of the McClymonds home found a number of places to improve its energy efficiency and reduce those energy costs.

In the living room, which is cool in the winter, Mr. Nadle suggested sealing the chimney above a little-used gas fireplace to prevent heat loss. Half of the basement is finished and well insulated, but in the unfinished section, he said insulation is needed on the back of the wall and door between the finished and unfinished sections.

In the unfinished basement he recommended better insulation around the windows and said the seams should be sealed on the sheet-metal air ducts leading from both the furnace and air conditioning unit to prevent leakage and promote efficiency. The furnace is a Bryant with a plus-90 percent efficiency rating. Newer models can boost that rating to as high as 96 percent.

All of the appliances in the kitchen are relatively new and Energy Star-rated.

In the second-floor hallway, Mr. Nadle noticed wispy cobwebs around several lighting fixtures recessed into the ceiling, which turned out to be less a comment on Mrs. McClymonds' housekeeping than it was on the home's energy efficiency.

"Spiders build cobwebs wherever there is air flow, so in those lights there is some heat leakage into the attic," he said. "You need to air-seal the attic and insulate around those lights."

After climbing up the pull-down staircase into the attic, Mr. Nadle said that although the McClymondses have added insulation they could use more to bring the home up to the R-38 rating recommended for the region. Insulation levels are specified by R-Value, which is a measure of insulation's ability to resist heat traveling through it. The higher the R-Value, the better the thermal performance of the insulation.

He also noted that one of the attic fans was not hooked up to a vent and there was no weatherstripping or insulation around the pull-down staircase. The unvented fan could be adding $5 to $10 a month to electric bills.

"Pull-down staircases are often quite leaky and without insulation they can leak heat into the attic in winter and heat the second floor in summer," Mr. Nadle said, adding that one of the best ways to air-seal the stairway is an insulated "coffin box" to cap the opening. Those can cost between $200 and $400.

All in all, Mr. Nadle said he was impressed with the energy-efficiency steps made by the McClymondses even though Mrs. McClymonds' husband, John, is more interested in the economics than the environment.

"I don't believe in global warming. I think it's total bull and a way to frighten people," said Mr. McClymonds, who owns Cranberry Supply Co., a trucking company with 18 dump trucks that deliver sand and gravel. "But if all this insulation can save us money in the long run, I'm all for it. And if we can get tax credits, I'm all for that too."

The company Erin Hasinger works for, Bicycle City LLC, promotes car-free communities, so it's only natural that she is interested in reducing her personal environmental footprint.

She traded in the SUV for a more fuel-efficient vehicle, her biggest recent "green" change; buys organic milk and eggs for her 8-year-old son, Alex; replaces light bulbs as they burn out with squiggly compact fluorescents, and, after seeing Al Gore's "An Inconvenient Truth," turned her thermostat down to 67 degrees last winter.

But when CCI home energy auditor Jonathan Nadle arrived at her townhouse in Gibsonia, she admitted that some of her efforts to "go green" have been less successful.

"I went to an environmental conference and found out that [Formula] 409 is bad for the world and decided to make my own cleaning products but I've found that vinegar doesn't clean windows as well as Windex," said Ms. Hasinger, 30, a single mother whose household also includes two cats, Jasmine and Zoey, and Jedi the dog.

"I tried composting in the back yard but had to give that up when the dog got interested in [eating] the pile. Then I went vegetarian for six months but got bored with the diet. Maybe because I didn't know what to eat or didn't like what I was eating."

She also said the living room of her 30-year-old townhouse, located on top of her garage, is cold in the winter and warm in the summer even though she hangs curtain liners against the cold and uses darker curtains in the summer to keep out the sun.

After telling her to cut the vinegar with ammonia to make a better window cleaner, Mr. Nadle toured the house and found a number of ways to make Ms. Hasinger's home more comfortable and more energy-efficient.

If the real estate mantra is "location, location, location," the real estate energy auditor's must be "insulation, insulation, insulation." Mr. Nadle said she needed more in the attic and above and around the garage.

"You need insulation in the attic to keep out the heat radiating down in the summer when the air conditioning is on, and keep the heat from escaping in the winter," he said. "And using cellulose dense-pack insulation in the garage will have the bonus effect of sealing the area to keep exhaust gases out of the house and preserve healthy indoor air."

Mr. Nadle said her older furnace and appliances are also costing her money in increased energy costs.

Her furnace is at least 13 years old and rated at about 80 percent efficiency, and that's when the filter is clean and sealed, which an inspection showed hers wasn't.

"At some point I'd recommend you go with a new high-efficiency furnace, one with a sealed and vented combustion system so no emissions are released inside," Mr. Nadle said. "The pet hair, dirt and dust clogging the filter means it's due for replacement, and I recommend sealing the filter slot so the furnace draws air from where you want it."

Ms. Hasinger's 26-cubic-foot, side-by-side refrigerator with an ice maker in the door is inefficient, wastes energy and is much too big for just her and her son. An older refrigerator can cost from $15 to $20 a month to run, compared to the $6 to $7 a month it costs to operate a new one.

"If she got an 18-cubic-foot model with the freezer at the bottom she could cut her energy costs for that in half and save more than $100 a year," Mr. Nadle said. "In weatherization work, payback in 12 years is considered reasonable so this would easily beat that."

Ms. Hasinger said she plans to act quickly on the audit's recommendations.

"The stuff he's talking about in the basement, putting tape on the ducts, caulking, changing the furnace filter, I can do that myself and fairly quickly," Ms. Hasinger said. "It's extremely helpful to get this information. Some of it will be expensive, but the changes will help me reduce my wasted energy and improve my comfort level and that's all good."

On top of the stationary tubs in the basement of Rod and Nancy Weiss' home in East Washington is a wooden bin, maybe four feet long, three feet wide and a foot deep. Painted proud on one of the side slats is the message "WORMS RECYCLE MY GARBAGE."

Mrs. Weiss started the vermicomposting project in 1990 as part of a display for the town's celebration of the 20th Earth Day and kept the worms going for 10 years. The wrigglers aren't working anymore, but in many other areas of their lives the Weisses are continuing to develop an environmental ethos that got its start when they were living in San Francisco in the late 1960s.

"We belonged to a food co-op when our daughter was little and we were living there," said Mrs. Weiss, 62, who works full time as a Washington County law librarian. "It opened our eyes to other alternatives."

In 1975 they moved to East Washington, where Mr. Weiss, 64, was a Presbyterian minister before retiring and becoming a part-time social worker. They live close enough to their job sites that both walk to work even though they've got a Toyota Prius sitting in their garage.

"When we bought it 3 1/2 years ago we couldn't justify the car on economic grounds. It was a hobby," Mrs. Weiss said. "Now, with gas prices up, it turns out we were ahead of the curve."

A stroll around the outside of their three-story wood-frame home with Indigo Raffel, CCI's education coordinator, turned up more pluses for their green lifestyle. The front of their home faces north, where a row of tall evergreens acts as a wind buffer in the winter. This summer, in raised beds along the east side of the house and in backyard plots, they grew tomatoes, pumpkins, zucchini, brussels sprouts, mint and basil. A grape vine climbs thickly up and along a small back porch, shading it. An apple tree they planted 25 years ago still produces well enough to attract foraging deer. Mr. Weiss mows his small yard with an electric lawnmower and there's a compost bin out in back by the garage.

"We grow vegetables and are buying more organics and fair trade items, and shop often at the farmers market in Washington," Mrs. Weiss said.

The sloped, south-facing roof at the back of the house would be a good place to install solar panels, Ms. Raffel said, or maybe incorporate solar shingles, which are less expensive, into a future roof replacement project. Their electric bill was $19 in July, $30 in August, and just $17 in September.

To provide all the energy for their home with solar panels would cost between $15,000 and $20,000, so that probably isn't cost effective.

Inside their home, the Weisses show Ms. Raffel the glass block basement windows installed in the 1980s. Five years ago they installed double-pane windows in the rest of their home. They have a 15-year-old Maytag washer and dryer in the basement that are working well enough to let the repairman keep snoring. When they break, they'll replace them with more energy-efficient models.

They've wrapped an insulation blanket around their water heater and would consider replacing it with a tankless model when it breaks. The tankless models cost $1,000 or more, up to twice what a regular hot water tank model costs but it's more energy-efficient.

They replaced their old gas furnace with a newer model several years ago, and keep energy costs further in check by not turning it on until Thanksgiving, no matter how cold it gets. When they do turn it on the thermostat is set at 60 degrees, 55 degrees when they go out.

Their gas bill, on a budget plan, has been $115 a month, but they recently received notice it will go up to $160 a month this year because of increased prices, not increased use.

"That's still good," said Ms. Raffel.

"Well yeah, but we freeze," said Mr. Weiss.

"Rob complains," Mrs. Weiss said, "but it pays off."

Mrs. Weiss said their first change as a result of the energy audit, before the solar array or new appliances, will be to increase their home's insulation. Mr. Weiss, who uses a space heater to make his arctic attic office livable in the winter, agreed.

"Anything you can do that saves energy is a big plus," Ms. Raffel said. "You should turn off all of your electronics, computer and television when not in use. All the little-by-little steps add up."