Energy Star for Multifamily High-Rises
The EPA's agreement with pilot partners cited the following criteria as those it would use to determine whether the Energy Star MFHR pilot program would be extended nationally:
- The performance specifications must be cost-effective.
- The program must represent true energy savings over standard construction.
- The program must provide value in the marketplace to MFHR stakeholders.
- The program must be easy to implement and understand, including energy modeling and verification protocols.
Eligibility and Criteria for Earning the Energy Star for MFHR
The pilot program applies to new construction of multifamily buildings four stories or higher. To be eligible for the Energy Star label, the performance target of the pilot projects must exceed by at least 20 percent the minimum requirements for energy efficiency in ASHRAE 90.1 2004, Appendix G. Projects must also be modeled to obtain a score of 75 or better on the EPA's MFHR benchmark tool, indicating performance in the top 25 percent of similar buildings nationally. Benchmarking is based on information on comparable buildings collected by the Residential Energy Consumption Survey (RECS) of home energy use and costs, conducted by the Energy Information Administration of the U.S. Department of Energy.
Also in progress are quality assurance measures, such as reviews of energy modeling and inspections of construction. Buildings, not individual units, may earn the Energy Star under this pilot program.
Case Study: Intervale Green, The Bronx, New York City
This multifamily residential project was developed on a triangle of city-owned property that had been vacant for more than 25 years. All apartments are rented to people earning below 60 percent of the area median income.
- Climate: Mixed-Humid (Zone 4)
- Space type: Multifamily residential with ground-floor commercial
- Size: 128 units (one to three bedrooms each); 140,800 square feet (13,080 square meters) residential, 6,800 square feet (630 square meters) commercial
- Completion date: 2008
- Construction cost: $155 per square foot ($1,668 per square meter)
- Total development costs: $29,237,815
- Owner/developer: Women's Housing and Economic Development Corporation (WHEDCo), Bronx, New York
- Architect: Edelman Sultan Knox Wood/ Architects LLP, New York, New York
Energy-Efficiency Costs and Savings
"We pursued the Energy Star designation to set an example that high-rise green building can be both affordable and beautiful," said WHEDCo President Nancy Biberman. The project includes two green roofs totaling 20,000 square feet (1,900 square meters); a private backyard; an entry courtyard; and a public garden.
- Estimated hard costs associated with energy reduction measures: $437,750
- Projected total energy costs saved annually (all fuels): $82,492 (over baseline ASHRAE 90.1 2004 building)
- Simple payback period: 5.3 years
- Savings-to-investment ratio: 2.8
Incentives and green building support were provided by Enterprise Green Communities, NYSERDA Multifamily Performance Program, Bronx Overall Economic Development Corporation's Bronx Initiative for Energy and the Environment, Home Depot Foundation, New York City Council, and the Bronx borough president.
The building is expected to use 33.4 percent less energy than the ASHRAE 90.1 2004 baseline building, resulting in projected savings of 208,401 kWh of electricity and 3,410 MMBtu annually. Energy-saving features include a high-performance building envelope, which features air sealing, continuous insulation, and insulated low-e argon-filled windows; 85-percent-efficient boilers and hot water heaters; carbon monoxide sensors in the garage, so ventilation only runs when needed; and Energy Star lighting fixtures and appliances.
The design team also received a code modification to reduce the excessive ventilation rate to a lower level while maintaining good air quality. Cary Trochesset, project manager for Edelman Sultan Knox Wood/ Architects LLP, said that without the ventilation waiver it would have been difficult to earn the Energy Star. The New York City building code has since been updated to make ventilation waivers unnecessary.
In addition to the two green roofs, part of which are accessible to tenants, green features include recycled-content flooring; low-flow faucets and showerheads; and low-VOC paints, adhesives, and sealants.
Tips from the Architect
Randy Wood, AIA, principal at Edelman Sultan Knox Wood, said his firm had already been incorporating many of the energy-efficient practices required by the Energy Star MFHR pilot program into the firm's projects. "I don't consider myself an expert; I just think it's what we should be doing, and we're doing it," said Wood.
"If there was anything that I found difficult," he said, "it was getting contractors to understand what they had to do and getting them to do it." Woods gave as an example sealing ductwork to comply with specifications, rather than as the subcontractor was accustomed to doing — which did not pass performance testing.
Wood's firm designs many low-income and subsidized multifamily high-rises, and Wood says that now many clients are asking them to evaluate the feasibility of participating in the Energy Star program.
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Linda Reeder, AIA, is an architect practicing in New Haven, Connecticut. Prior to starting her own firm, which is focused on residential projects, she worked on the design of commercial, multi-family, and institutional buildings. The former editor for Building Performance for the AIA's Architects Knowledge Resource web site, Reeder has taught classes in sustainable design and construction in the Construction Management program at Central Connecticut State University and in the Department of Architecture at the University of Hartford.
This article is excerpted from Guide to Green Building Rating Systems by Linda Reeder, copyright © 2010, with permission of the publisher, John Wiley & Sons.
Project: Intervale Green (New York, New York)
Owner/Developer: Women's Housing and Economic Development Corporation (WHEDCo)
Architect: Edelman Sultan Knox Wood/ Architects LLP
Energy Consultant: Steven Winter Associates, Inc.
Structural Engineer: Robert Silman Associates
Mechanical, Electrical, and Plumbing Engineer: Abraham Joselow, P.C.
General Contractor: Mega Contracting, Inc.