Even if you don't have a green thumb, you can appreciate the fact that you'll save...

Here's a passive way to be aggressive about helping the planet. This age-old approach to design uses the sun's energy and the flow of air to heat a building and keep it cool, either as a supplement to or instead of mechanical systems. Design features include appropriate orientation and location of the structure for best airflow and sun; windows that open for good ventilation; and thermal mass-stone, brick, or concrete walls and floors (or even large containers of water) that absorb heat and slowly release it-which allows for the collection, storage, and distribution of the sun's heat. No greenhouse gases are produced by such a system, and it will lower your heating costs, so it's that rare expression of passive-aggressive behavior you can feel really good about.

Ever since the Environmental Protection...