You've banned plastic bags from your home, swapped out the incandescent light bulbs for compact fluorescents and have replaced the shower heads and toilets with low-flow models.

So, what's the next step for homeowners who want environmentally friendly and energy-efficient "green" homes?

You can be as green as you want, but the goal for all is the same: to minimize the dent we make each day on the environment, from driving to work alone or using hardwoods rapidly lost to clear-cutting in the Amazon jungle.

Still, it's a bit scary to think that the way we've been living all these years is now suspect. Sustainability - the concept that materials we use should be renewable and used for the long term - is a long way from the days of "planned obsolescence."

"Rest assured, efficient living does not mean radically changing your lifestyle," believes home designer Alan Mascord of Portland, Ore. "The key is to know how a product works for you, where a product comes from, what you will do with it when you are done and how much it costs for you to operate."

Mascord's company, Alan Mascord Design Associates Inc., has teamed with Whirlpool Corp., a leader in making Energy Star-rated appliances, to produce a book showing how houses can be built in the mass market using green principles that emphasize durable construction techniques and materials.

Complete with floor plans and an interactive CD, the book is one of the first of its kind. With a foreword by architect Sarah Susanka, a leader in the "less is more" movement, it is titled "Mascord Efficient Living: Build a More Sustainable Lifestyle" and is available at mascordefficientliving.com or Amazon.com for $14.95.

Beyond its many plans for new houses, the book is a good primer on elements comprising green homes and gives homeowners ideas on where to go next to improve the sustainability of their houses.

THE INS AND OUTS OF GOING GREEN

Using one of Mascord's designs, we've consulted with greenhousing specialist Stephen L. Kapp, technology manager for the Center for Sustainable Energy in San Diego, to suggest what homeowners in a typical tract house should consider when making the move toward green. It's a choice that can result in considerable economic benefit and the knowledge that the Earth will be a bit less bruised.

Here are Kapp's suggestions:

INSIDE

1. Refrigerator. Make sure it's Energy Star rated. If it's more than 10 years old, chances are it's an energy hog. Features such as ice makers or door-mounted TVs add more to the bill. A rebate may be available to haul off your old one.

2. Electronics. Make sure computers, video games, TVs and cable boxes are shut off with a power strip when not needed, as they still draw electricity even if they're not in use.

3. Fans. Make sure fans such as those in the kitchen, bedrooms and bathrooms are rated for the task needed and use the least electricity necessary for the job.

4. Light bulbs. Compact fluorescent lights (CFLs) are available for virtually any fixture, including those outdoors. However, they might not provide light instantly; use the older bulbs in areas where light is needed pronto. Beware: Not all CFLs are Energy Star rated. Consider sensors that turn lights on and off when rooms are occupied or vacant.

5. Programmable thermostats. They'll help keep your heating and air-conditioning bills down if you don't want to tinker daily with the settings.

6. Shower heads and toilets. Some shower heads are now super-low-flow, using only 1.5 gallons per minute vs. 2.5 gpm models; for every 10 minutes in the shower, that's 10 gallons saved. Toilets, too, now come in ultra-low-flow models, with some having an option on how strong a flush is needed.

7. Washers and dryers. Front-loading washing machines use less water. Moisture sensors on newer dryers tell when it's time to shut down automatically.

8. Water heaters. Consider a tankless model, a compact unit that provides hot water on demand. But check first that the high cost is worth it, compared with newer, energy-efficient traditional tank heaters. Simple step: Turn down the heat setting on your present water heater.

9. Paint. Make sure paints and stains are rated low-VOC (for Volatile Organic Compound).

OUTSIDE

10. Fencing. Consider fire-resistant, recyclable, woodlike materials instead of the real thing.

11. Compost bins. Composting organic waste creates rich soil for plants and keeps it out of landfills; about one-third of landfills is taken up with material that could be composted.

12. Landscaping. Drip or underground irrigation systems allow native plants access to water while minimizing waste.

13. Outdoor solar lighting. Exterior lights can soak up the sun's rays during the day and illuminate sidewalks or stairs at night.

14. Recycling bins. Putting recyclables in the recycling can on trash day may be easy, but visits to the recycler instead are a quick way to boost the allowances of your children.

CONSTRUCTION AND MATERIALS

15. Insulation. Check the insulation to see if it meets the minimum standard for your climate zone. Upgrade your insulation with either blown-in material, or batting with a vapor barrier. If you're tearing apart exterior walls, now is the time to add insulation and a weather barrier such as Tyvek.

16. Flooring. For carpeting, check to see if the product carries a Green Label from the Carpet and Rug Institute showing it meets criteria for the release of volatile compounds. Also, consider natural flooring such as stone, slate, bamboo or cork, or recycled materials. Linoleum is back, this time as a "green" product.

17. Cabinets and lumber. Check on the origins of the wood you plan to use in cabinetry, as well as in lumber. Be sure the wood is certified, showing that it is a sustainable product as judged by a third party such as the Forest Stewardship Council.

18. Duct work. Make sure that ducts are sealed mechanically or with a mastic compound. This is one job where duct tape won't do.

19. Solar panels. Check on the various systems and any available rebates and credits. You could be the first on your block to go into business - selling electricity to the power company.

20. Roof. Consider a green roof. It can increase the life span of the underlying roofing materials, while reducing heating and cooling costs and the amount of storm water flowing into drainage systems.

21. Windows. Replace single-pane windows with double pane, Low-E coatings (for low emissivity) that keep heat out in summer or in during the winter. This can be an expensive proposition, however. Make sure it pays off. Sealing gaps is the first place to start.

22. Porous driveways. Driveways designed for percolation let rainwater soak into the ground instead of storm drains.

LOOK FOR THE LABELS

The three main national certification programs for green-built houses:

- Energy Star. Most people think Energy Star ratings are for appliances and electronics, but entire houses can be Energy Star-rated as well. Home builders must meet guidelines established by the EPA.

- LEED. The U.S. Green Building Council's Leadership in Energy and Environmental Design program issues rigid performance standards and grades houses and other structures.

- National Green Building Standard. Developed by the National Association of Home Builders, the program brings a national dimension to already established green programs formed by local home-builder associations. The criteria includes use of locally derived materials and recycling of surplus building materials.

ORIENTATION

To maximize the sun's benefits, a home should be positioned on an east-west axis with the greatest number of windows on its south side. To prevent excessive exposure to the sun in summer, overhangs or other shade elements should be used. Minimizing the number of windows on the east and west sides reduces exposure in early morning and late in the day, when shading is difficult due to the low angle of the sun.

Visit Copley News Service at www.copleynews.com.