ZOOMAZIUM'S GREEN STORY
The Zoomazium building was registered with the LEED program with a target of silver certification, the third level in the rating scale. The LEED (Leadership in Energy and Environmental Design) Green Building Rating System® is a voluntary, consensus-based national standard for developing high-performance, sustainable buildings. Members of the U.S. Green Building Council representing all segments of the building industry developed LEED and continue to contribute to its evolution. In late 2006, Zoomazium received GOLD certification, the second highest level in the rating scale.
Our building incorporates the following environmentally friendly features:
Green Roof: a vegetated roof system on the large curved upper roof (approximately 8000 square feet, measures 116' long and 69' wide, and slopes gradually along a 225' radius from0:12 to 3:12 at the low edge on the east side of the roof). The added cost of the green roof and related structural requirements over a conventional roof was $241,668.
The roof system is a total of 14 ½” thick. From top to bottom it is composed of:
Plantings: 20,977 in all (salal, sword fern, kinnikinnick, nodding wild onion, blue-eyed grass flower, western polypody, blue-pod lupine, sand strawberry)
Specially blended lightweight soil (40 lbs. per square foot when dry, 55 lbs. per square foot when wet) - 6” deep
Filter Fabric Reservoir Board - assists in drainage, and stabilizes the roof system ¾”
Drainage Mat - ¾”
Monolithic Rubberized Asphalt Membrane (keeps the building dry) ½” Plywood (sealed seams) - ½”
Insulation - 5 ½” thick
Plywood (sealed seams) - ½” thick
Research and design for the vegetated roof system included extensive coordination of system and details with technical experts from American Hydrotech (basis of design manufacturer) to determine profile, system layers and related details. Plantings were determined through research by the Mithun landscape team, and included input from a variety of sources, including soil and plant experts and the zoo horticulture staff. The design team paid great attention to lessons learned from other recent green roof failures, and have held extensive conversations during the construction process with civil engineers, soil experts, the vegetated roof manufacturer and plant and soil suppliers to determine the absolute best soil mix to provide the best growing conditions for FSLC plantings. Additionally, the zoo working with the City of Seattle set up green roof monitoring to document the effect on reducing stormwater runoff.
Natural Ventilation package (includes operable windows, remote operating mechanisms, etc.)
Flack+Kurtz provided mechanical and plumbing services for the FSLC. Mithun worked closely with their engineers to determine the optimum natural ventilation strategy for the building. The design of the building is based on a strategy of high and low vents and cross ventilation. Flack+Kurtz recommended location and amount of operable vents through ventilation modeling.
Natural Daylighting package (includes windows, skylights in office area, daylight sensors, etc.)
Mithun worked with the BetterBricks Daylighting Lab to study daylight harvesting in the building, both in the main exhibit space and the lower administrative areas. This involved a large scale physical model of the building design which included photographs of the existing trees to determine the amount of solar shading provided naturally by the site and to be designed into the building overhangs and screens.
Energy Conservation package (includes insulation, high efficiency lighting, lighting controls, energy management system, etc.)
Mithun worked with Hultz/BHU/Cross engineers and Flack+Kurtz to determine ways to minimize energy use and maximize flexibility of use. This involved a careful selection of compact fluorescent and other energy efficient light fixtures and the integration of a building management system to allow efficient control of building systems. Daylight harvesting will also help to offset the need for artificial lighting in the building.
Recycled Content Materials package (includes carpeting, concrete, etc.)
The design team worked to include recycled content products wherever possible, including products such as the carpeting and walk-off mats. Importantly, the building design also utilizes a high fly-ash content concrete mix, where fly-ash (a waste by-product of burning coal) is substituted for 40% of the typical Portland cement content to reduce the embodied energy of the mix while achieving the desired strength goals. Mithun and WPZ conducted extended core strength tests of this mix to see how it performs over a year long span. This data will serve as a resource for future Mithun and WPZ (and other) green building projects to help promote fly-ash content concrete usage.
Forest Stewardship Council-Certified Wood in the exhibit space (sustainable forest practices)
All of the glu-laminated beams in the project are Forest Stewardship Council certified. The FSC serves as a benchmark for sustainable forest practices to enhance wildlife habitats and ecology through better stewardship of timber forests.
Green Solar Screens (planted walls screening the support area windows) reduce heat gain and provide privacy for office area
The vegetated screens are strategically placed to create a visual buffer between the public pathway and administrative spaces, while filtering low early sun and also softening the presence of the building for visitors on the main pathway.
Siting of the building so that large existing trees to the west provide sun screening for that side of the building
The existing foliage played a crucial part of the building design and site relationship. Conceptually, the vegetated roof is an extension of this forest canopy, and the transparency on the west side is intended to create a strong visual connection to the forested area to the west. The building also borrows natural shading from these trees to minimize solar heat gain from afternoon sun.
Native Landscaping was used around the building in keeping with the Temperate Forest setting of Discovery Village
Native landscaping was chosen to enhance the Northwest Forest Biome experience and to minimize necessary irrigation. These plants will also be a valuable educational tool in the Zoomazium experience.
Raised Access Floor makes future program changes easier to make and also serves as the air plenum for the heating and cooling of the exhibit hall.
Adaptability is an essential component of sustainable design. If a building cannot change to meet new program requirements and uses, then energy and resources must be expended to modify it or replace it. The access floor allows a great deal of future flexibility for changing exhibits and program elements, while also serving as an air supply plenum to create more efficient heating and less ductwork.
Pattern Glass made up of white dots on the inside of the outer layer of glass layers, that make the windows appear to be more like something solid, to help reduce the likelihood of bird strikes.
Transparent glazing continues to have a detrimental effect on bird populations in urban and rural settings. While there are no guaranteed prevention strategies for bird strikes, there have been some studies that have shown a reduction in bird strikes by altering the continuous amount of transparent area in a pane of glass to less than 4 square inches by using a pattern of stripes, dots, or other design. In the course of Mithun’s research, they consulted with Daniel Klem, an ornithologist at Muhlenburg College, who has produced several publications on the subject. Klem consulted in the glazing design for new buildings at Swarthmore College that are currently using fritted dot pattern glazing to reduce the likelihood of bird strikes. The patterned glass will also serve to reduce solar heat gain in the building.