Green vs. High Performance
Article by James E. Gleason, Architect, Gleason Design Group
Many builders today try to refer to their homes as being green or a green built product. Our builders today are more educated in building science than ever before, and many cities, municipalities, and professional organizations are encouraging more of the aspect of Green Building. Typically people think of green as being only energy efficiency. Even though green and high performance homes have similar characteristics, I have another opinion on the subject. Most homes built by quality builders in the central Texas area, whether speculative or custom built are most likely considered high performance homes for the following reasons:
Bigger Is Not Always Better
First, one aspect of green building is to only build a home that is comfortable for the immediate needs of the owner (s). In Texas we are under the philosophy that bigger is better. In actuality it is not according to green building guidelines established by many green building groups. Builders try to fit their building programs in order to be able to build the maximum size product within the least amount of time for the most profit. I can’t blame the builder for this because it is in his best interest to make profits. But over size building is not a green concept.
The idea of green is not to waste natural resource materials and to design with minimum requirements, have multi-use spaces, and make the home incremental, so that it can be added onto in the future when the family grows. We should ask questions such as, how big do our living room and bedrooms need to be? Do we need two dining areas? Are walk-in closets necessary? Etc.
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Close to Work, Schools, Banks, Stores and Public Transportation
Building a house green is to have the home located near work, schools, banks, grocery stores and on public transportation routes instead on one acre lots in the country. This would eliminate the unnecessary waste of automobile fuels and encourage walking and bicycle riding. The lawn and landscape areas should be small to eliminate mowing which uses fuel and presents unwanted gases into the atmosphere. Outside living entertainment and cooking areas should be encouraged to place people back in the outdoors for health reasons and for less use of energy required inside the home.
Use Efficient Energy Technologies
Another green design requirement is to have passive solar designed into the home using natural sun light for much of interior daytime lighting needs, window directions to encourage natural ventilation and properly sized overhangs to protect the structure and eliminate solar heat gain into the home. The home should be designed for future energy applications such as active solar or wind generation that can be added easily without a great amount of additional cost. Mass should be incorporated into the home to help hold temperatures for long periods of time. This can be accomplished by masonry feature walls, hard surfaced floors or plastered walls.
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Built for Durability and Low Maintenance
Homes that are built green should be durable with less maintenance than traditional built homes. In America, thirty year mortgages are common because usually the home begins to deteriorate and requires more repairs and rebuilding after that thirty year period resulting of loss of real value. Green built homes should have a life expectancy of more than one hundred years and should be designed with characteristics to be congruent with future building of homes in the area.
- Foundations. Foundations should be engineered and built with a thorough knowledge of soil and environmental conditions and provided with proper surface drainage from the foundation areas. Elimination of soil gasses under the foundation is an important consideration for health and structural reasons.
- Construction Materials. Selection of construction materials is important not to waste our natural resources. Materials should be grown, harvested, manufactured and supplied from a distance as close as possible to the construction site, in order not to waste fuels for transportation. Finger joint studs, engineered beams and headers, and advanced framing techniques should be incorporated to eliminate the over use of natural resource materials. Use of OSB (Oriented Strand Board), which is made from lumber waste products, needs to be considered for structural integrity. Selections of cementuous exterior sidings, trims, fascia and soffit materials can make the exterior of the home durable and long lasting while conserving our resources. Recycled insulations and drywall materials are other green solutions.
- Exterior Applications. Care should be taken in selection of exterior applications to ensure longevity, proper wall drainage planes applied to resist deterioration, and certain design features to ensure protection of exterior features. Exterior walls need to be engineered, flashed and constructed correctly, then secured with wind ties and straps. Maintenance free energy windows and exterior doors applied and sealed properly to the exterior walls. Quality insulation installed and checked to ensure the best possible application is applied.
- Interior Finishes. Interior finishes need to be selected for long lasting applications, such as cement backer boards behind wet areas for interior drying of the wall. Proven plumbing and electrical fixtures along with energy efficient appliances, proper floorings, countertops, and splashes for duration. Paints and stains should be investigated and used with low VOC’s (Volatile Organic Compounds) which makes the home healthier. Cabinets made from fast growing wood or recycled products are advantageous. MDF (Medium Density Fibrous) boards, which are also made from lumber waste, can be used for trim. Bamboo is a fast growing and plentiful resource material used for flooring which can make the home healthier from elimination of dust.
- Mechanical Systems. Mechanical systems have to be engineered and sized properly for the home. One mistake that many builders make is to over size the HVAC (Heating, Ventilation, Air-conditioning) system, over sizing the HVAC system will result in loss of efficiency and the use of more electricity. If the home is sealed properly, insulated correctly and passive solar designed into the home, then the HVAC system needs will be much less than traditionally built homes. The HVAC system should have outside air introduced and mixed with the return air, properly filtered and then conditioned through the system before being provided throughout the home. Shortening of insulated duct work and proper return air locations is a part of the engineering process. Humidity control has to be looked at and controlled properly within the structure. Homes with these characteristics use up to half of the typical air conditioning needs while saving energy and making the home healthier.
- Water Heating. Water heating is an important factor and is a concern of both green and high performance homes. Heating applications that should be considered are solar water heating, on demand water heaters, and at the minimum typical water heaters with insulated jackets and timers to control the waste of energy when the unit is not needed.
- Construction Waste Recycling. Elimination and recycling of construction waste is important in green building. Every year billions of dollars of material are hauled off or worse, burnt or buried on our construction sites. Builders and subcontractors need to be properly educated on the conservation and recycling of construction materials. Left over masonry, drywall and wood waste can be ground or shredded, and incorporated into our landscaping. Subcontractor trash such as cans, bottles, and paper can be carried to local recycling areas.
In green building it is important to protect the immediate area around the home so as not to destroy existing natural vegetation and natural wildlife existence. Barricades and parking areas for construction vehicles should be provided to protect the surroundings. The landscaping should be designed with native plants conducive to the area and ones that are drought resistant. Irrigation systems need to be designed not to waste water. Some green builders are providing rain water collection systems and underground storage tanks for landscape irrigation. Driveways and sidewalks made of pervious pavers or gravel materials help recharge the ground water into the soil. These items can help conserve usage from our domestic water systems.
Education is probably the most important solution to green building. The builder as well as the homeowner needs to understand proper techniques and solutions to be successful in green building. The builder must learn from green and building science educational programs and from qualified green architects. It is easy for a builder to provide quality windows, good insulation, and efficient HVAC systems, creating a high performance home, but to take it to the next step, he has to be accountable to our environment. It is the architect’s, the builder’s and the home owner’s moral responsibility to protect our natural resources and our environment. And that may be the toughest building job of all.
Gleason Design Group
Architect, James E. Gleason
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