Trees help the environment by absorbing CO2 and other airborne pollutants (through a process called photosynthesis) then stores the carbon and releases oxygen.
According to the Arbor Day Foundation, strategically placed trees can increase home energy efficiency. In summer, trees shading east and west walls keep buildings cooler. In winter, allowing the sun to strike the southern side of a buidling can warm interior spaces. If southern walls are shaded by dense evergreen trees there may be a resultant increase in winter heating costs.
Use the ENERGY STAR Home Energy Yardstick to compare your home's energy efficiency with that of similar homes across the country. You'll need your utility bills from the past 12 months, and once you answer a few questions about your home you'll receive a report of recommendations.
Seal and Insulate
According to the ENERGY STAR website, sealing and insulating is often the most cost effective way to improve energy efficiency and comfort. They estimate that a knowledgable homeowner or skilled contractor can save up to 20% on heating and cooling costs (or up to 10% on their total annual energy bill) by sealing and insulating. They recommend sealing air leaks throughout the home to stop drafts, adding insulation to block heat loss in winter and heat gain in summer, and choosing ENERGY STAR qualified windows when replacing windows.
A quick way to see if you need more insulation is to look across your uncovered attic floor. If your insulation is level with or below the attic floor joists, you probably need to add more insulation. The recommended insulation level for most attics is R-28 (or about 12-15 inches, depending on the insulation type). In the coldest climates, insulating up to R-49 is recommended. Click on the image below to see what insulation is recommended in your area.
Heating and Cooling
As much as half of the energy used in your home goes to heating and cooling. So making smart decisions about your home's heating, ventilating, and air conditioning (HVAC) system can have a big effect on your utility bills - and your comfort. According to David Bach in his book, Go Green, Live Rich (Broadway Books, 2008), adjusting your thermostat up or down by just three degrees Fahrenheit all year round will save you about $114 on a 1,500-square-foot home and will keep two and a half tons of carbon dioxide out of the atmosphere.
The Energy Stare website offers recommendations for increasing the efficienty of your heating and cooling system. These include: changing your air filter regularly (at a minimum every 3 months), tune up your HVAC equipment yearly, install a programmable thermostat, seal your heating and cooling ducts, consider installing ENERGY STAR qualified heating and cooling equipment.