Energy Requirements & Options
HOW ENERGY EFFICIENCIES SAVE YOU MONEY
Building Construction – Energy Efficiency Explained
Energy Efficiency can be defined as BTUs per square foot of building per year for heating, electricity and appliances. The Green Street buildings will be held to a high standard of energy efficiency.
A variety of options, for building, appliances and beyond, can be used to meet this standard: amount of insulation in the roof and walls, house tightness (restrictions on air leakage), heat recovery ventilation (HRV), window choices, fuel choices and appliance efficiencies, purchase of offsetting renewable energy to achieve “net zero” efficiency.
Green Street will focus on what can be achieved with thoughtful design and construction, plus fuel choices of natural gas and solar electric.
It is assumed that the buildings will include the following:
1. Insulation: R Values of R20 for the basement, R 40 for the walls, and R70 for the roof. Bast & Rood recommends dense pack cellulose and foam insulation in the building envelope assembly.
2. Windows will be double and triple glazed.
3. House tightness – 0.3 air changes per hour at 50 pascals.
4. 80 cfm Heat Recovery Ventilation.
Calculate Building Energy Efficiency Cost Savings
The above standard of Energy Efficiency, versus current standard of building efficiencies, should save you $654 to $746 per year depending on the heat source. For a typical 30 year mortgage time period the savings would be $19,620 to $22,380. If heating prices climb, the savings will climb also.
Natural Gas: In addition, all houses will use natural gas as the primary heating fuel. Green Street has signed an agreement with Vermont Gas Systems which does allow the home buyer to add a number of additional energy sources: solar hot water, photovoltaics, a wood stove, a wood boiler, air source heat pumps. Green Street homes may not use electricity or oil for heat.
Solar Electric Panels: Green Street has installed 32 Kw of solar electric trackers in the field along Charlotte Road, to generate solar power which feed directly into the Green Mountain Power grid. This power is generating an annual offset to participating electric bills.