The financial benefits of investing in a Passive House
GO Logic is an architecture, design and construction firm building Passive Houses designed for cold climates. As a design-build firm, the efficiency of project delivery from concept to completion is improved over standard project delivery systems. The result of these efficiencies is a shorter planning and construction period, and a finished product with improved long-term energy performance. These improvements in process and product result in both first-cost and lifecycle savings for the home buyer, saving money on construction and the long-term operating costs for the home. To demonstrate the investment value in a GO Logic home, we have compared the construction cost and lifetime energy savings of a Passive House vs. a standard built home in today’s dollars. The calculation compares the typical lifetime (30 year) costs of each construction method, taking into account inflation and operating costs. A Passive House uses only 10% of the energy for space heating of a standard built, code-compliant home. Given The Northeast’s cold climate, this level of energy performance has a significant impact on the life-time energy costs of the home. In standard built construction, the cost of space heating is typically 75% of the total energy used by a home, with the remaining energy balance divided roughly evenly between the domestic hot-water and plug loads. Reducing the space heating demand therefore has the greatest impact on reducing a home’s total energy consumption and related energy costs. In terms of the actual cost savings of space heating on an annual basis, comparing a 1,500 square feet standard built home with a Passive House, the savings for space heating is estimated to be $1,400 per year. Reducing the space heating demand of new construction in a cold climate has a significant environmental benefit, and if properly designed, a critical first-cost and life-cycle cost savings as well. Because a Passive House’s energy demand for space heating has been reduced by 90%, the resulting heat required to keep the build at 70 degrees is very low (2000 watt peak demand), which allows a Passive House’s traditional heating system to be drastically simplified to a small amount of electric baseboard controlled by a thermostat in each room. The cost to install this simplified heating system is about $500, replacing the standard heating system consisting of a boiler, radiant slab, pumps, fuel tanks, chimney and manifolds, saving around $15,000. The significant financial savings resulting from minimizing the heating systems is reinvested in the building shell improvements, including: walls at R49, foundation at R70, roof at R80 and triple glazed R8 windows and doors. The cost of these improvements is about $30,000. When the cost of the heating systems is subtracted from the building shell improvements, the first cost increase for building a passive house about $15,000, or 7% of the total construction cost. The combination of these improvements, in conjunction with heat recovery ventilation, results in a home with energy costs for space heating at less than $300 per year, with energy costs savings over 30 years of $170,000 (including inflation) which is about 70% of the original cost of construction. Furthermore, on account of the minimized heat load, a 2.8 KW solar electric system and a separate evacuated-tube solar thermal system mounted on the roof will cover the building’s space heating and hot water needs, resulting in a grid tied near zero energy building on an annual basis.
