Near Net-Zero Home
The primary goal of a high performance Net-Zero energy home is to be self-sustaining,
maximize the energy efficiency while at the same time generate power. Maximizing
energy efficiency involves a holistic approach with many options. Power generation
primarily comes from the sun and wind.
With solar panels on the roof, a windmill in the yard, this Quail home in Southwest Washington is the first to achieve LEED Platinum certification. LEED, which stands for Leadership in Energy and Environmental Design, is the U.S. Green Building Council’s measure of environmental impact. Platinum is the highest possible designation, signaling an efficiently built project that minimizes use of water and energy. Only 45 houses in Washington have been certified LEED Platinum. With the wind turbine and solar hotwater heater, this home also has the potential to a Net-Zero energy home, depends on the life style and energy usage of the occupant. Another option for the occupant is to add solar photovoltaic panel next to the solar hotwater panel that is already on the south facing roof, to generate more electricity.
Passive Solar Features
- Faces directly south for optimum light and sun exposure 168 degrees.
- Front roof is 30 degree angle for optimum sun exposure for this latitude, for Solar Hot Water and photo-voltaic Solar Panels.
- South overhang is calculated for maximum sun radiation during winter and no direct sunlight through the windows during summer months.
- House is rectangular design for maximum light and sun exposure,
- South windows are 70% of total windows in the home. Gathering natural light and solar gain for heating.
- Cement slab construction creating a thermal mass for heat gain during the day and slow release of the heat during the night.
- North side has no windows and is protected from winter north winds by the natural terrain and protection of the garage on the north side.
- West side has only 2 windows for protection from the sun during the summer months.
Active Solar Features
- Solar Water Hot Water panels with photovoltaic array to operate the pump for the heat exchanger. Completely self contained system and uses no other electricity for operation.
- 2.2 KW Wind Generator
- 3 KW Photovoltaic System (2011)
- Hot Water continuous recirculation system. Instant Hot Water 24/7. Saves heating costs and water usage.
- Radiant heating system on 5 zones. Surplus Hot Water from Solar Water System will help with radiant system.
- Fresh air recirculation system using an air to air heat exchanger 24/7.
- Drip irrigation system. No Turf. All trees, ornamentals and plants are native to the Northwest and are drought tolerant. Ecoscape Design. Irrigation reduced by 59%.
- Dual Flush Toilets. Uses 40% less water than current codes.
- All faucets and showerheads have flow restrictors installed.
- Pavers are used in front entrance and rear patio instead of cement or wood decking. which allows water to flow through cement and go in the aquifer and not into the storm water system.
- Storm Drain for roof and rear retaining wall runoff, goes directly into the aquifer and not into the city storm water system.
- All appliances are Energy Star Rated.
- All lighting is fluorescent with 4 Halogen bulbs in Kitchen.
- Radiant Heating tankless water heater is 95% efficient. It is gas fired and uses about ½ the space of a conventional forced air system. Produces 12 gallons per minute of 120 degree hot water.
- A 3000 KW system will provide 50% electricity for the home. Estimated usage will be 550 kw per month. The remaining power will be sold to Clark Public Utilities on a Net Metering System. Estimated annual billing to utility will be $800.00-$1000.00. (2011)
- All chemicals (Paint, Varnish, Sealers etc) had no or low VOCs. (Volatile Organic Compounds)
- Most of the wood came from a Sustainable Forest.
- 90% of all materials came from a local source. (500 Mile Radius)
- Construction waste was kept to a minimum and recycled when possible.
- Kitchen hardwood floor from a sustainable forest.
- 60 ft retaining wall made from recycled concrete.
- Sip Panel construction (Structural Insulated Panels). Absolutely airtight with an R-Value 10% over standard 2x6 Stud construction. 5 times more stronger than standard construction.
- 30% Federal Tax Credit for total materials and labor for Hot Water System, Wind Generator and Photovoltaic System. This will expire in 2016.
- $2000.00 Federal Tax Credit to the Builder for using the SIP Construction or similar approved tight building system.
- Washington State Sales Tax Exemption of 8.2% for Solar Hot Water System, Photovoltaic System and Wind Generator. This will expire in 2014.
- $1000.00 direct rebate from Clark Public Utilities for using Solar Hot Water system with electric water heater. The projected additional construction costs for the above features are about are 10-15% additional from standard construction. Due to increasing energy prices and added value to the home, the projected financial payback will 7-9 years.
The above information is taken from The