Green Achievements

The development team set out with a goal "to identify a reasonable standard for healthy and energy-efficient affordable housing in Boston," according to architect Nancy Ludwig. Her firm worked with developer Trinity to ensure everyone involved in the development process understood the green aspects of the project.

The team focused on the following criteria in order to meet their green goals: Leadership in Energy and Environmental Design (LEED) certification; photo-voltaics as a renewable energy source; a high-performance building envelope; resident health and comfort; and an aggressive pursuit of energy savings. The team specifically focused on receiving a LEED NC certification for the Phase I midrise A building. This effort in Phase I informed decisions in subsequent phases. At first, Ludwig says, there was some skepticism about green design, but by the end of the process, Trinity was very proud of the project. Now the developer is focusing more on building green projects.


Note: This case study primarily focuses on Phase I. Project Size:

Phase I: 5 buildings with one midrise containing

116 units and 4 low-rise buildings containing a total of 34 units. Total project: 396 units in the 4 phases; 1.7 acres

(21 buildings); 5 new city streets. After initial occupancy, the total target mix of incomes = 29% at 0-10% of AMI; 34% at 11-30% of AMI; 14% at 31-60% of AMI; 23% at market rates. Cost/Unit: Phase I: $360,000

Construction Cost: Phase I: $25,423,227 Development Cost: Phase I: $54,000,000 Total project: $121,000,000

Completion Date: Phase I: December 2004

Whole project: December 2006 final Phase IV completed and occupied (4.5 years for design and final construction)

Project Team Developer:

Property Manager: Architect: General Contractor:

Legal: Engineer:

Landscape Architect: Solar Design Consultant: Energy/Green Consultant:

Trinity East Boston Development, a partnership of Trinity Financial and East Boston Community Development Corporation Winn Properties ICON Architecture CWC Builders and Dimes Construction Hale & Dorr McPhail Associates, Environmental Engineers Geller DeVellis Solar Design Associates Massachusetts Technology Collaborative and NE Energy Efficiency Council

High-Performance Building Envelope: To minimize energy consumption, a tightly sealed, highly efficient building envelope was designed. The envelope's R-value is 20 percent higher than required by the Massachusetts energy code. Additionally, fiberglass windows with double-glazed, low-e glass were specified. Using fiberglass helps control condensation and thermal bridging,3 thus lowering heating and cooling costs while prolonging the life of the building components. Ludwig notes that this approach helped to "buy down" or reduce the size of the mechanical system.

Resident Health and Comfort: Resident health and comfort was a priority. Fresh outside air is delivered directly into the units, providing ventilation that exceeds code requirements. The LEED requirement toward no-smoking specified high-performance air sealing to eliminate the transfer of smoke from unit to unit. In addition, several apartments, as well as all common areas, are designated nonsmoking.

To reduce the environmental factors that cause asthma, low-volatile-organic-compound (low-VOC) materials and hard surface flooring such as Marmoleum were used. In addition, all wet areas (i.e., kitchens and baths) have smooth and cleanable surfaces that do not trap moisture, thus reducing mold production. To specifically accommodate residents with asthma, 15 units were designated to be carpet-free, and another 15 have a significantly reduced amount of carpet and feature Marmoleum flooring in all bedrooms.

Photovoltaics as a Renewable Energy Source: Using the MTC grant to research and implement on-site renewable energy generation, a 37kW photovoltaic (PV) system was selected and mounted on the roof of the midrise building. Along with the PV system, a 75 kW natural gas cogen-eration system2 produces all the power necessary to light the building's common areas, run its elevators, and act as a backup for domestic hot-water heating.

Aggressive Pursuit of Energy Savings: Part of the energy efficiency strategy included seeking incentives and rebates from KeySpan, NSTAR, and ENERGY STAR® for incorporating high-efficiency lighting, ventilation, appliances, and equipment into the building design and operation. Ludwig noted that ENERGY STAR's best-practice program4 helped guide the design team in the areas of insulation ratings, types, and levels; air-sealing strategies for the building; interior ventilation standards; and suggestions on



• Access to public transportation: Maverick Square, major public transit hub, mile away

• High density of 88 units per acre

• Water-efficient landscaping; planting species all native to the area and drought-resistant


• LEED NC used to guide the design (LEED certification pending)

• Window placement and size allows for ample daylighting.

• High-performance fiberglass-composite-frame double-glazed low-e windows

• "Smart" mechanical systems: variable-frequency drives and energy-efficient equipment and motors

• High-efficiency boilers

• Highly efficient gas absorption chiller

• All appliances ENERGY STAR® rated

• Renewable energy: photovoltaic (PV) array and 75 kW cogeneration system

Materials and Resources

• Local materials include structural steel, wall panels, concrete, and granite

• Recycled-content materials such as concrete, steel, and carpeting used throughout

• 50% of construction waste generated from the project recycled

Health and Comfort

• All units conform to Boston Housing Authority's Healthy Homes criteria for floor and wall finishes. Low-VOC paints, adhesives, and materials

• Variety of housing designs creates a living environment of individuality and family friendliness building wall design. For example, use of a white high-albedo5 ENERGY STAR®-compliant roof membrane was a key factor in the conservation of energy and was important for controlling heating and cooling costs in the building. Light-colored roofing materials with high reflectance have been shown to reflect up to 85 percent of solar radiation, thus reducing unwanted heat gain when compared with conventional surfaces, which reflect only 20 percent of solar radiation. In addition, a collaborative design and implementation process with energy raters allowed for review and suggestions on the initial building design, in-process site visits, and final testing of the completed building.

The development team incorporated a commissioning process that verified that fundamental building elements and systems were designed, installed, and calibrated to operate as intended. Ludwig believes this thorough process was instrumental in ensuring the optimal performance of the buildings. She says that the commissioning process6 enhanced occupant comfort, reduced utility costs, and increased building value. It also resulted in a reduction in costly change orders during construction and helped maintain the project's construction schedule.

0 0

Post a comment