Across the nation, shopping center owners and national retailers are implementing environmental design strategies. Increasing numbers of building owners and mall managers are finding that sustainable, or green, design is a cost-effective and energy-efficient holistic approach for new and renovated retail properties.

"Sustainable design projects are good for the environment and provide unique features in the competitive retail market," says John Civilinski, director of real estate for Gravestar Inc., a Cambridge, Mass.-based company that manages and redevelops shopping centers in New England.

"We systematically evaluate every part of the project so the outcome is positive, not detrimental, for the environment," Civilinski adds. "This evaluation includes use of green (less toxic) building materials, solar energy, daylight, light technology, photovoltaic systems and energy systems exceeding minimum standards. Energy savings and cost efficiency enable the owner to meet or beat market return on investment."

For the redesign of Porter Square, a Cambridge shopping center reopening this month, Gravestar retained New York City-based architects Croxton Collaborative and Henry S. Cole and Associates to consult on sustainable design programs, along with Arrowstreet Architects of Somerville, Mass. As Gravestar's hometown flagship project, the redesign meets one of the company's main goals in providing an environmentally responsible retail center for the community's working families.

Gravestar's redevelopments are more than cosmetic. According to architect Randy Croxton, FAIA, principal of Croxton Collaborative, several factors come into play in environmental design: water quality, bio-remediation of pollutants, energy efficiency, maximum use of renewable energy, use of benign building materials, resource conservation and optimal waste streams.

Porter Square's key features include above-standard R-35 roof insulation for New England temperature variations; energy-efficient glass; rooftop photovoltaic energy panels; a "gray," or non-potable, water recovery system for landscaping; and specification of flooring materials and paints with low toxicity and offgassing properties. Offgassing is the normal gas emission or odor from a process, equipment or a material.

Community amenities are integral to Gravestar's redevelopment planning philosophy. Porter Square provides bike racks; ride shares and carpooling areas; subsidies for the "T," the local subway system; and home delivery of groceries. These convenient, environmentally friendly approaches help reduce car trips for the students, working families and young executives in the neighborhood.

Gravestar also retained Croxton to design the redevelopment of two older suburban Boston centers: Sudbury Plaza and Woburn Mall, prototypes for the company's future property upgrades. At both sites, indigenous trees and vegetated swales reduce flood risks, stabilize the microclimate and provide shaded areas.

"We try to tie the life of the shopping center to community issues," Croxton explains. Woburn Mall's own nature preserve will include shelters for hikers, while Sudbury Plaza will have a playground. Both sites include several heating, air conditioning, refrigeration and lighting energy conservation strategies in partnership with tenants. The goal is to achieve a transition to 100% renewable energy sources.

REI's conservation ethic In the Northwest, REI's Seattle flagship store has raised the bar for environmentally responsive design. It is now applying this new aesthetic to other national locations. REI (Recreational Equipment Inc.) was founded in 1938 as a membership co-op importing Austrian ice axes.

The company remains committed to a conservation ethic, protecting the outdoors for recreation and building resource-efficient stores, says Bert Gregory, AIA, principal in charge and project designer for REI stores at Mithun Partners, a Seattle-based architectural firm. The stores are typically freestanding buildings, but the sustainable design and energy management features could readily apply to malls and shopping centers.

During early planning for the 96,000 sq. ft. Seattle store, REI's design goals included use of environmentally appropriate materials, cost efficiency, proven technology and an attractive retail environment. Focus group surveys subsequently identified other top priorities: energy efficiency, use of recycled materials, recycling and reuse of construction and demolition waste, keeping materials out of the waste stream, alternative transit options, and water conservation.

Green specification REI uses a variety of active and passive energy-saving strategies, from a computer-controlled energy management system to carbon monoxide sensors that activate exhaust fans in the 475-car garage only when needed. Other noteworthy features:

* HVAC. The store's signature story space and climbing wall enclosure - which makes up about 5% of the typically conditioned space - are not directly mechanically heated or cooled. This portion of the building uses computer-controlled louvers to bring in outside air (forming a stack effect with the climbing tower) and waste air from the retail area to partially temper the space.

* Site and building design. The building is sited for optimum solar energy collection. Large louvers protect windows on the south and west facades to minimize heat buildup from the morning sun.

* Lighting. Natural day lighting is used extensively, with motion sensors detecting occupancy for after-hours lighting. High-efficiency sodium vapor lighting is used in garages; high-efficiency metal halide and fluorescent lighting is used within the building, with some fluorescent track lighting to highlight special areas.

The Seattle electric company, City Light, credited REI with an energy rebate for achieving an efficiency target, and the significant savings helped pay for other areas. Newer, 25,000 sq. ft. REI stores are so efficient they generate a three-and-a-half-year payback to pay for skylights and lighting control systems integrated with the HVAC. Generally, high-efficiency lighting reaps savings for lighting loads but requires more energy to cool spaces.

* Circulation. There are no escalators in the building to consume additional energy. Instead, the two main retail levels are served by two handicapped-accessible elevators. Outside, numerous bike racks are provided for customers and employees; employee showers encourage bike usage. REI also provided a covered bus stop.

* Building materials. Recycled materials include countertops from recycled newspapers; walk-off matting from recycled tires; landscaping from composted urban green waste; and salvaged wood, timbers, windows, steel and concrete retaining walls.

Mall management "Energy-efficient malls are good for landlords and tenants. When landlords control costs, tenants can control their costs as well," says Brian Griffin, director of operations for Chicago-based General Growth Properties. General Growth builds and opens about one new project a year, but renovates and reuses many existing properties whenever possible for cost efficiency. A design criteria manual for tenants outlines storefront materials and local codes.

Some areas of the country maintain energy restrictions, requiring mall developers and designers to operate within an interior watts per square foot (w/sf) budget. Griffin says the Brassmill Shopping Center in Waterbury, Conn., achieved the local utility company's energy budget of 2 w/sf, a common benchmark in the Northeast.

In the Southwest, companies manage energy capacity more effectively because of limited supply. Buildings are not sited on an east-west axis due to heat gain from the intense southern light.

Buying into green design Will consumers buy into retailers with a green habit? According to Mark London, president of Lake Bluff, Ill.-based Mark London & Associates LLC, consultant to shopping center owners, green design is one of many enticements for mall owners and consumers.

"The trend is toward open, glazed areas and greenscaped indoor malls," he notes. "The average suburban community prefers an unenclosed, lifestyle specialty center over a strip mall or a megamall, as do many retailers. The 'return to Main Street' concept can readily address sustainable design."

But London claims these Main Street centers, with 30-foot storefronts and specialty retailers offering personal services, mean more to consumers than using recycled building materials. "The design, format, access and feel of the center is most important. Greenscapes, good lighting and the big picture mean most to the consumer," he adds.

Nevertheless, as more communities and local governments formally endorse environmentally responsible practices, sustainable design and mandated energy conservation may become the rule rather than the exception.

For example, Phoenix-based Westcor Partners, developer of FlatIron Crossing, a $212 million center in a growing high-tech corridor near Denver, promised the local community a host of environmentally friendly practices as a selling point to build the project. The 1.5 million sq. ft. mall, slated to open in 2000, will make use of recycled building materials, alternative energy sources, electric vehicles for the security force, and gray water for irrigation.

If local neighborhood groups convince a mall developer to adopt similar eco-friendly approaches, the project will likely be more palatable to the community. When this trend catches on, everyone will be seeing green - both environmentally and financially.