Wednesday, April 22, 2015

For Earth Day: 22 Shades of Green

Sheri Koones Apr 21st 2015 5:08PM
Updated Apr 21st 2015 5:18PM
Courtesy of Mandibule
The Positive Energy ECOXIA House in Yerres, France, is a certified Passivhaus, built for sustainability and efficiency.
There are many options available for those who want to build a "green" house. The number of sustainable and energy-efficient options used in the construction is dependent on budget, taste and the level of desire to be independent of the grid and utilize sustainable practices.

Here is a checklist of things to consider when building or remodeling a home to be sustainable and energy efficient:

1. Insulation
First and foremost, use excellent insulation. Be sure there is adequate insulation, whether it is spray foam, cellulose, fiberglass, etc. The foundation, attic and exterior walls must all be properly insulated.

2. Air Sealing
Be sure to check for air infiltration. This can be done with a blower door test that will show where outside air is coming into the house. A tightly sealed home requires less heating and cooling.

3. Windows
Buy the best windows you can with your budget. Today there are many options in design, frame material, color and efficiency of windows. There are double and triple-pane windows, as well as gas-filled ones. Even frames can be insulated. Also, when designing a home, it is wise to have more windows on the south side of the house to take advantage of solar gain. Having fewer windows on the north side of the house prevents solar loss in those areas.

4. Appliances
Use ENERGY STAR-rated appliances. They consume far less energy than non-rated ones. That saves energy and dollars throughout the life of the appliance.

5. Non-toxic Materials
Make sure all stains, finishes, paints and adhesives are no-VOC or low-VOC. These toxins can continue to seep into the air and can cause illness and discomfort.

6. FSC-certified Wood
Using wood certified by the Forest Stewardship Council helps provide healthy forests for future generations.

7. Passive Solar Orientation
Orient the house for optimal solar gain, if possible. This limits the need for artificial lighting and saves money on electricity, while also reducing energy costs.

8. Footprint
Limit the hallways in the house. Space should be used efficiently so there are fewer square feet to heat and cool. When a house is well designed, less space can still provide all the areas and functions desired.

9. Multi-functional Rooms
For example, a guest bedroom can easily work as an office or playroom when friends or family are not visiting.

Courtesy of Jim Tetro
The 4D House built by Team Massachusetts for the Solar Decathlon has a partition wall that can be closed for privacy in the bedroom or opened to increase the entertaining area.
10. Flexible Rooms
Walls can sometimes be moved to open up space for entertaining, as seen in a house built by students at the University of Massachusetts for the Solar Decathlon, a competition staged by the U.S. Department of Energy.

11. Ventilation
To maintain a healthy indoor environment, a tightly built house requires adequate ventilation.  Heat recovery ventilators and energy recovery ventilators are systems that continuously exchange the stale inside air with fresh outside air, while retaining the warmth or coolness already created in the house.

12. Low-flow Faucets and Showerheads and Dual-flush Toilets
Both of these substantially reduce the water being used in the house.

13. Recycled, Reused, and Reclaimed Materials
This limits our depletion of natural resources as well as the amount of material that goes into landfills. There are many types of recycled, reused and reclaimed materials -- including countertops made with recycled glass, reclaimed flooring and antique furnishings.

14. Lighting
LED and CFL lighting uses less energy than incandescent bulbs and the bulbs last much longer. The cost of these efficient bulbs is going down, and the variety of bulbs available has expanded.

15. Large Overhangs
Large overhangs around the house block the sun's heat in the summer months when the sun is high in the sky. In the winter, when the sun is lower in the sky (in the northern hemisphere), overhangs allow the sun to come in through the windows and help heat the house.

16. An Efficient Water Heater
Traditional water heaters maintain a tank full of warm water and are continuously using energy. Tankless water heaters heat water on demand.

17. Native Plant Landscaping
Using plants indigenous to the area limits the need for irrigation and fertilization.

18. Permeable Paving
Using paving materials that are permeable, such as gravel, allows rainwater and melted snow to return to the water table.

19. Solar Hot Water Panels
The cost of solar panels is coming down and there are subsidies available to reduce the cost further. Hot water panels can be used to heat the household's water or be used as part of a radiant heating system.

20. Photovoltaic Panels
PV panels can be used to reduce or eliminate the electric load. While connected to the grid, they can provide electricity when it is needed and receive electricity when the sun is not out. Extra electricity can also be returned to the grid to reduce electric costs.

21. Thermal Mass
Stone and other high-mass materials can be used to absorb energy when the sun beats down on them. That heat (or coolness) can later be released when it is needed. Some houses have stone around the periphery of the room where the sun is most likely to hit.

22. Heating System
A heating and cooling system that limits the energy consumed should be used. Heat pumps are becoming more popular in this country and quite popular around the world. They can be used successfully when the house is built with a very energy-efficient envelope.