Green Home Building Techniques, Science & Technology
A house is a system of interconnected elements. SunTerra strives to combine all the parts with careful emphasis on economics, durability, maintenance, comfort and health.
SunTerra’s success in designing and building homes depends upon understanding the dynamics of the physical forces that create a tug of war between the outside and inside environments. A SunTerra home applies the principles of building science in both design and construction. It balances many building elements to achieve superior performance with an affordable investment in proper insulation, quality windows, efficient heating and cooling systems, airtight construction, controlled ventilation and solar orientation. These features make a SunTerra home the most comfortable home you’ll ever live in.
Thermal Mass Construction
Sunterra Homes has developed and patented an exterior wall system that takes building efficiency performance to the next level. These exterior featured walls of decorative concrete blocks store up to 10 times more heat energy than standard wood-framed homes. This wall system is strong and quiet with continuous exterior insulation eliminating the thermal bridging of wood framing.
Does it cost more than wood? Yes. Does it normally save more in heating and cooling cost than it adds to the annual mortgage interest? Yes.
SunTerra recommends choosing products that can store a high level of heat energy in the home construction.
SunTerra Homes use only as much wood framing as is structurally necessary, providing more room for insulation. This construction method eliminates structurally unnecessary wood members and replaces them with structural spray foam insulation.
Advanced framing conserves wood, reduces heat loss and saves money without compromising the structural integrity of the building.
SunTerra Homes built with the new SunTerra EnergyBlock wall system is presently only available in the Northwest region of the United States at this time.
Eaves receive special attention to address a common source of heat loss and potential water damage. Roof framing methods often affect energy loss. Many homes use trusses instead of rafters that rest directly on exterior walls. This leaves little space for insulation. Not only does this waste energy dollars, but heat loss melts snow which then refreezes, forming ice dams that can cause extensive moisture damage.
SunTerra homes use a variety of methods to ensure adequate insulation. One method is the “raised heel truss” that raises the roof framing to allow the full layer of insulation to extend over the exterior wall. See illustration at right.
If the home is constructed with roof rafters, we can reduce heat loss through the ceiling by choosing the hot-roof design. It acquires its name because it does not require ventilation for moisture control.
As illustrated in the roof wall section, if we keep moisture from getting into the structure from the outside and prevent moisture laden air from achieving dew point in the structure from the inside, we do not need venting.
This improves the effectiveness of the insulation because air is not wiping away the heat.
Conventional roof framing pinches insulation near the eaves and allows for excessive heat loss.
Energy-efficient roof framing allows enough space over exterior walls for full thickness insulation.
Both style and construction of windows needs to be considered. The styles of windows to provide the best long-term air tightness are fixed, casement, and awning units. Casement and awning units use compression type weather stripping that historically lasts longer than the sliding type seals used with sliders and single hung windows.
Triple pane ” Low-E” glass is the minimum window glazing recommended for cold climates which provides an insulation value of R-5 or U-.20.
Because of superior insulation and air tightness in the roof and walls, it is not uncommon for more than 40 percent of the heat loss in a SunTerra home to occur through the windows. Choosing window coverings that are good insulators can have a major impact on reducing heat cost and further improving comfort. If you choose a window covering that has an R-5 insulation value, you could reduce the heat loss of your home by 20 percent when window coverings are drawn.
|Casement and Awning||.46||.29||.27||.20|
|Single Hung *||.50||.30||.28||.22|
|Horizontal Slider *||.50||.31||.29||.22|
|Patio Door *||.50||.32||.30||.25|
The smaller the U-Value number, the more efficient the window.
* Not recommended for Energy-Efficient Homes
Passive Solar Home
Solar energy brightens every day, and it’s free. Passive solar should be considered for every home design. It can provide a significant percentage of a home’s heating and still maintain good interior comfort levels.
Sun spaces brighten a home’s interior and can be incorporated in many areas of a home. They bring outdoor beauty inside with the warmth of the sun.
By adding a thermostat and fan to distribute solar-heated air, the heating effectiveness and comfort within the home are enhanced. This same blower can be used to force ventilate and cool your home in the summer.
Heating and Cooling
There are few design decisions that affect your home as significantly as your choice of a heating and cooling system. The heating system affects both long and short term costs, comfort, health, and resale value of your home.
Cutting-edge equipment and careful installation combine for high-efficiency. SunTerra Homes has incorporated several types of high-performance heating and cooling systems to further reduce annual energy expenses. These include: ductless heat pumps, geothermal heat pumps, air-to-water heat pumps, active solar and night flush passive cooling.
Alternative heating systems, including solar and waste heat recovery, capture free energy for your home. Your home’s hot water needs can also be reduced by the use of the high-performance energy systems installed in most SunTerra homes. Active solar in many areas is a good choice for preheating your hot water. It can contribute up to 80 percent of the energy needed.
Because some high-performance systems require a substantial initial expenditure when compared to conventional equipment, the expense of a system and its savings potential are extremely important considerations. The availability of solar energy, cost of utilities, the siting of your home, equipment and installation costs, energy savings, etc. must all be carefully evaluated.
Federal, state and utility companies offer financial rebates and tax credits for the use of alternative energy systems to help offset the additional installation expense.
Controlled ventilation maintains indoor health and comfort. Air quality in homes has become poor as builders strive to make homes tighter. SunTerra Homes realized it is not practical to try to build a home so it leaks just enough but not too much.
The SunTerra approach is to build as tight as economically possible and include controlled, heat-recovery ventilation. This assures healthy air quality, reduces heat loss, and keeps homes cleaner and more comfortable with optimizing energy cost savings.
Heat stays in and drafts stay out with SunTerra’s unique insulation packages. When evaluating insulation, look for more than R-value. Thermal performance is important, but so is air infiltration and moisture control. Prevention of mold and structural rot along with thermal storage benefit is key.
While several types of insulation can reduce heat loss, air infiltration, and moisture condensation within the exterior shell of a home, SunTerra has evolved toward a cost-effective hybrid approach that combines structural spray-foam and batt insulation or the SunTerra EnergyBlock wall system.
Our latest innovation is the SunTerra EnergyBlock, a decorative masonry wall with continuous, exterior insulation reducing heat loss over two times the energy code requirement.
Another option is the strapped wall, which adds horizontal furring strips to add depth to a standard 2 x 6 wall and higher R-value. Both approaches have proven to be the right investment when evaluated with climate and cost of fuel.
INSULATIVE BENEFITS OF FOAM INSULATION
- Higher “R” value up to R-7 per inch
- Eliminates air leaks
- Stops mold and rot conditions
- Reduces sound though walls and roof
- Adds Structural strength to home
- Fills gaps while expanding
- Long-term thermal resistance
- Classified as a green product
INSULATIVE BENEFITS OF SUNTERRA ENERGYBLOCK
- Higher “R” value up to two times that of the International Energy Conservation Code
- Eliminates air leaks
- Moisture, mold, rot and pest resistant.
- A very green product that is exceptionally eco-friendly.
- Adds Structural strength to home
- Long-term thermal resistance
- Walls of concrete, steel and rigid foam board provide good sound insulation for a strong and quiet building.
Energy conservation, superior indoor environmental quality and resource efficiency make SunTerra a leader in sustainability.
Many SunTerra designs are characterized by space-efficient floor plans which reduce resource consumption. Good site integration and passive solar features offer cozy comfort and free energy.
SunTerra also recommends materials that promote health and reduce natural resource requirements. These include: SunTerra EnergyBlock walls, Forest Stewardship Council certified lumber, recycled content building materials, fluorescent and LED lighting, low-VOC paints and finishes, and high-efficiency appliances to name a few.
An alternative-energy heating and cooling system, and domestic hot-water system is a device that replaces a conventional fuel, oil, electric, or gas-fired furnaces, and boilers or resistance electric heaters. The most common heating alternatives today are passive solar, active solar, air-to-air heat pumps, air-to-water heat pumps, water-to-water heat pumps, and ground source heat pumps.
An Alternative Electric System
Photovoltaic solar cells convert sunlight directly into electricity, with an almost negligible loss of power. A home equipped with such a system could be electrically self-sufficient, provided it made prudent use of electrical power and relied on active solar, propane or wood for heating back-up and major appliances.
As we watch energy costs increasing, alternative energy systems become more competitive to conventional power sources.
Today when we design an energy-efficient home, we need to evaluate the cost of incorporating alternative energy for the home. Compare:
- Cost of ownership for alternative energy system
- Estimated increase in cost of energy
- Life and maintenance of system
- Resale value of home
- Impact to life style and community
SunTerra recommends building an all electric home. Electricity can be generated by all conventional and alternative energy sources. Let’s save fossil fuels for use other than housing needs. Alternative Energy Systems are being promoted by Government and Utility Companies. SunTerra will work for you to take advantage of these programs.