DLR Group's Eco Alternative team met all 10 design objectives to take first place in a regional green competition sponsored by the USGBC. The diverse team of four creative, young architects incorporated equally diverse and creative strategies to win the competition by employing passive ventilation, a spacious courtyard for social functions, water collection and recycling for storm water run-off, roof gardens and much more in its solution to create a sustainable transit neighborhood corner for the USGBC's Emerging Green Builders Natural Talent Design Competition - Mississippi Headwaters Chapter.
Integrating a transit community with a sustainable design solution drove this Saint Paul, Minn. project. The winning design is a sustainable, urban, mixed-use project that integrates people, communities, environment and transit along a proposed light rail route in Saint Paul. The Central Corridor Light Rail Transit (LRT) line is part of the larger transit network that will serve heavily traveled corridors in the Twin Cities metropolitan area. The plan is intended to improve mobility, build transit ridership, slow the growth in traffic congestions, and provide economic stability in the area.
Twenty-two teams of students and young professionals volunteered their time and vied for the cash prize. Two teams from DLR Group's Minneapolis office placed first and third in the competition. DLR Group teams were the only teams in the field of 12 to use Revit, which is a single file database that can be shared among multiple users. Plans, sections, elevations and schedules are all interconnected, and if a user makes a change in one view, the other views are automatically updated. Thus, Revit drawings and schedules are always fully coordinated in terms of the building objects shown in drawings.
The USGBC's challenge was to create a buildable project that provides access to the existing community while providing a progressive and walkable district that encourages local and small-scale pedestrian commerce, affordable housing, public transportation use and community gathering. The 10 design objectives were structured around social consciousness, integrated design, sustainability, innovation, constructability, affordability, zero net energy, multi-cultural consideration, life cycle costs and integrated urban design aesthetic.
One of the stations proposed along the 11-mile LRT line is located at University Avenue West and Lexington Parkway North. The mixed-use project was designed to occupy a 1.5-acre site and was required to meet a host of green building objectives. The project was also designed to earn a LEED platinum award. The various sustainable features the buildable project offers include the following:
- The tower's stack effect facilitates a passive wind exhaust, which creates a convection air flow that can preheat air before entering the mechanical system similar to a heat exchanger.
- Photovoltaic energy systems help to produce renewable energy and reduce the need for fossil fuels.
- A balcony with photovoltaic louver systems provides dual functions: It prevents the interior space from overheating during summer months while collecting energy to reuse throughout the living unit or it could be incorporated into a power grid that services the whole block.
- Shared roof garden space reduces radiation and induces natural ventilation in the building by means of mass dissipation, creating a more viable air temperature in occupied spaces.
- Outdoor roof playground minimizes pollution impact on children while creating a secure place to play.
- Southeast opening between buildings generates passive cooling throughout the site and eliminates stagnate air pockets.
- Natural day-lighting through clerestories / atriums reduces energy consumption by replacing artificial lighting where applicable.
- Operable lower windows / louvers provide intake for passive air ventilation and allows for user control of their domain.
- Southwest building orientation allows for maximum winter heat gain through building mass and expansive window openings.
- Deciduous trees minimize summer overheating through shading and provide summer evaporative cooling.
- Shared tiered gardens with pervious surfaces reduce storm-water run-off and heat island effect while providing visual and physical amenities to the user.
- Sunspace provides passive solar heating and serves as a heat exchanger between spaces.
Eco Alternative's mixed-use project incorporates two towers that form outstretched arms to the public traffic on University Avenue, live/work units, a recycle center, a rooftop playground, community flex space, courtyards, carpool drop off, bike storage and showers, an LRT pedestrian connection and the light rail station.
Commercial spaces are provided on the first and second levels of the towers along with the lower level of the live/work units. These two-story live/work units are important in connecting to the neighboring community and promoting unique and diverse family-run businesses. This opportunity makes residents more involved in the development, reduces their commuting needs and attracts visitors to a shopping experience they can't find at big retailers.
The multiple-level live/work units are designed with retail shops on first and second levels while owners and residents live in upper-level units. Some upper-level residents will have loft-like units that incorporate two floor levels rather than one because narrow floor plans promote passive ventilation throughout the living space.
The "architectural elements create the connection between public and private realms," said Eco Alternative team member Christina Wagner. The design "encourages foot traffic with wide pervious sidewalks with greenery on both sides and skyways between buildings that also incorporate a green environment." The design also accommodates the full-time residents who might live there and takes into consideration the "least mobile person" whether they're in a wheelchair or have difficulty walking.
Andres Permadhi added, "The design is based on open views to achieve views for building occupants in 90 percent of regularly occupied areas." Curves were incorporated for design interest, appeal, circulation and interactivity.
Light is introduced through an atrium between two towers, which can "deepen daylight penetration into a space." The design of the atrium also allowed for stacked ventilation capabilities that along with the narrow floor plates of the loft like units could decrease the demand on mechanical systems during non peak periods through passive ventilation.
This was "our attempt in describing how passive ventilation design could be used in Minnesota," said Wagner. The team's solution was based on its studies of how the buildings are sited, weather patterns, solar gain, radiation absorption, smaller footprints, green roofs and public/private gathering areas.
A three-story church has a playground, commercial kitchen, exercise rooms, flexible space for the community and below the church are showers and communal bath area.
Jury members said that Eco Alternative's winning design had an "excellent handle on LEED points and technology" and "lots of green space - more than most of the other entries." Additional jury comments included the following: good tie-in and access point to and for the surrounding neighborhood, connects well with the LRT, dense and large enough to be affordable, good layout and plan for walking - good "flow" and access to green areas, children friendly, feasible to build, good mix of uses.
Eco Alternative won $1,000 for the design and will advance to the national competition at the Premiere Greenbuild Conference and Expo being held in Chicago, the sustainable design and construction industry's largest annual conference.
# # #