Westwood Hills Nature Center – Design for Ecosystems

2023 DESIGN AWARD RECIPIENT

Westwood Hills Nature Center – Design for Ecosystems

The interpretive nature center teaches environmental stewardship and Zero Energy strategies. HGA worked with the City of St. Louis Park and allied partners to design the Net Zero Energy / Net Zero Positive building as an educational teaching tool, demonstrating passive and active strategies for energy efficiency and sustainability. “This project recognizes the City of St. Louis Park’s commitment to environment stewardship and connecting people with nature,” said Marc L’Italien, FAIA, DBIA, LEED AP, Design Principal at HGA. “The city envisioned this building as an integral part of its conservation mission enhancing residential, commercial, and public spaces. Sustainability literally shaped every aspect of the building to create a community destination that promotes life-long environmental learning and engagement.”

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There is clarity in the architecture; the project has beautiful transitions and terrific use/combination of materials.

Noteworthy performance features include:

1. Each design feature of the project was calibrated for energy use and resource conservation.

2. Design that integrates into nature with a special emphasis on resiliency and flexibility.

//framework for design excellence measures

Measure 1: Design for Integration

The main performance goal of the project was to achieve an ILFI Zero Energy Certification, but the overall mission of the institution, and particulars of the site landscape, necessitated that the design address broader goals than simply energy use. Early resilience planning ensured the design address the effects of a changing climate—warming and increased precipitation events—and the shifting demographics of residents, to anticipate both the energy needs and programming needs of the building. Connecting people to nature required the combination of site/building design and an interpretive planning approach. Integrated systems, architecture and interior design create an expression that serves as a teaching tool itself for programming in addition to incorporating interpretive exhibits. The building and site design work together to manage stormwater and provide interpretive opportunities to visitors. Building structural, material, and finish selections were made to reduce carbon impact, and increate interior air quality.

Measure 2: Design for Equitable Communities

To increase the impact of the Center’s mission, it was critical to expand the reach of the facility through inclusive design. Both the physical facility and planning process used the lens of equity and community impact as design driver. Updated interpretive planning and exhibits allow a greater variety of programming and topic areas, and the nature center has renewed its relationships with the local school district to provide wide ranging curriculum for kids of all socioeconomic levels.

Measure 3: Design for Ecosystems

The nature center landscape includes examples of regional biomes, surrounding a lake and marshland. Stormwater management, critical to the evolution and history of the site, forms the conceptual basis for the site design. Included are a relocated bog, a clarified existing pond, and new infiltration basins with native plantings. An interpretive feature uses rainwater captured by the building’s roof to exhibit site hydrology. The building resides in a lively bird habitat and uses two types of bird-friendly glass. Plantings were located strategically to minimize bird strikes.

Measure 4: Design for Water

The building and site design provide an interpretive example of best stormwater management practices. The building, sited near the marshy wetland, captures roof and site rainwater runoff, and treats to minimize impact. The rainwater runoff captured from the roof feeds an underground storage pipe, from which rainwater is pumped via both solar and hand powered pumps through a series of filtration basins to form an interpretive feature demonstrating the area hydrology. Further filtration basins with plantings treat runoff by reducing the discharge of sediment and phosphorus off site.

Measure 5: Design for Economy

Establishing the ‘energy budget’ for the project enabled the design, owner, and construction manager team to prioritize and protect the budget for building systems as weighed against other construction cost factors. The zero energy design mandated the elimination of natural gas energy source on the project, reducing carbon impact of combustion. A wood structure was created to be exposed, and is integrated into the architectural design to eliminate unnecessary ceilings and finishes; spans are optimized and roofs cantilever where possible to eliminate additional foundation work.

Measure 6: Design for Energy

The building is all-electric, having no source of combustion, in keeping with ILFI Zero Energy Certification requirements. Annual power usage is offset by onsite generation via a 160kW rooftop photovoltaic array.

Measure 7: Design for Well-Being

Critical to the design are strategies for connecting occupants to the nature. Daylight and views are prominent throughout. Daylighting strategies reduce energy and create even distribution of daylight while avoiding glare conditions. Photosensors and dimmable LED fixtures, and the strategic use of reflective soffits along the classroom corridor, work together to provide evenly daylit spaces. Flooring, paint, and ceilings materials were selected based on their environmental and human health attributes, with evidence of product transparency and third-party certifications.

Measure 8: Design for Resources

The building’s elemental architectural palette of wood structure and polished structural concrete slab reflect the conceptual attitude of using the exposed components of the building as a teaching tool. SFI certification was specified for wood structure on the project, and the use of wood was deliberate for both its experiential warmth and its lower embodied carbon footprint relative to other structural options. Windows and glue-laminated wood structural elements were fabricated regionally, reducing transportation impacts. The bolted connections of the structure allow for future deconstruction.

Measure 9: Design for Change

A resilience workshop was held to assess potential risks to the project, including climate change impacts. Future weather data was used to verify the building’s systems’ performance, ensuring net zero energy use over its lifespan. Predicted climate changes, including warming temperatures and increases in precipitation events, were factored into the HVAC and stormwater management systems. The building’s flexibility allows for a variety of uses, and its design was tested to hold up to a range of potential climate futures. The building’s layout and operable partitions allowed for adequate social distancing and alternative programming in response to the COVID-19 pandemic.

Measure 10: Design for Discovery

Integrating concepts from all disciplines in the conceptual design phase is key to addressing sustainability. The project achieved ILFI Zero Energy Certification, with ongoing energy monitoring. It was presented as a case study for resiliency planning and design, highlighting response to future climate projections. The project has won a 2023 AIA COTE Top Ten Award. Occupant behavior was found to be crucial to building performance, with strategies like notifying staff of ideal temperature and humidity conditions and providing individually controlled ceiling fans. These measures reduce the building’s energy expenditure and allow systems to work more efficiently.