Whether you realize it or not, you home is taking advantage of passive solar heating. Passive solar heating is simply the production of heat from sunlight coming through your windows and heating internal surfaces. Don't believe me? Walk around your home during the day and see if rooms that have direct sunlight are hotter than those that don't. Trust me, they will.

You can use passive solar to cut 20 to 30 percent off your heating and cooling bills for the year. During the winter, you can let the sun in as much as possible to heat the home. During the summer, you can keep it out as much as possible to lower the temperature in the home and your cooling bill. How do you do all of this? With natures thermostat ? trees.

To control the exposure of your home to the sun, you should plant trees in your yard. Specifically, you want them on the south facing wall where the sun will hit your home the most. The trees should be placed in front of the larger windows, maybe 10 to 15 feet away depending on their height. The idea is to put them close enough that they will block the sun in summer.

So, what about winter? Well, you need to select and plant a particular type of tree. We are not talking about a particular species, just a tree that is deciduous. Deciduous means the tree sheds its leaves during the winter. Since you want as much sun as possible to penetrate your windows in winter, this loss of leaves effective accomplishes your goal.

By plating deciduous trees in strategic positions next to your south facing walls, you can effectively control how much sunlight penetrates your home. Plant them and you can smile as your utility bill goes down, down, down.