Denver Botanic Gardens Science Pyramid

The Botanic Gardens' new 5,258-square-foot Science Pyramid's iconic design reflects a blend of progressive design, sustainable technologies and biomimetic principles that mirror the building's purpose—the advancement of science. Intended to showcase the fascinating research being done at the Gardens on contemporary botanic and environmental issues as well as topics like the global steppe climates, the new space will empower visitors to become citizen scientists and do their part as ambassadors for global conservation as a part of the Gardens' broader mission. Various projects conducted under the Gardens' Center for Global Initiatives will also be featured.

Client: Denver Botanic Gardens (Brian Vogt, CEO) Green inside and out, Denver Botanic Gardens began in 1951 and is considered one of the top botanical gardens in the United States and a pioneer in water conservation. Accredited by the American Alliance of Museums, the Gardens’ living collections encompass specimens from the tropics to the tundra, showcasing a plant palette chosen to thrive in Colorado’s semi-arid climate. The Gardens is a dynamic, 24-acre urban oasis in the heart of the city, offering unforgettable opportunities to flourish with unique garden experiences for the whole family – as well as world-class education and plant conservation research programs. Additional sites extend this experience throughout the Front Range: Denver Botanic Gardens at Chatfield is a 750-acre native plant refuge with an active farm in Jefferson County; Mount Goliath is a high-altitude trail and interpretive site on the Mount Evans Scenic Byway.

Background: Denver Botanic Gardens' Science Pyramid was commissioned through a formal design competition seeking teams to join previously selected general contractor GH Phipps Construction Companies which had been tasked with creating an iconic structure to house exhibits featuring the Gardens' conservation and research efforts. The competition had specifically requested a Pyramid with dynamic glass elements. The Burkett Design team, during that phase, included Boulder-based Studio NYL as structural engineer/enclosure consultant. They began their design process by reinterpreting the simple pyramid form in more modern terms, and adjusting it to respond to the Gardens' primary circulation paths, daylight angles and programmatic needs. This resulted in a splitting and manipulation of the form to accommodate aesthetic, functional and programmatic needs. Because it was quickly determined that an all glass pyramid (similar to the Pyramide du Louvre, I.M. Pei's glass and metal entrance pyramid at the Louvre in Paris) was impractical, given the programmatic needs of a museum featuring digital and projection exhibits, it was decided that the pyramid would be defined by an opaque enclosure. Ultimately, the building's form catalyzed an intriguing blurring of elements—raising the question, "Which parts are truly walls and which parts are roof elements?" The need for a consistent material as the enclosure transitions from roof to wall, resulted in the selection of Swisspearl© fiber cement panels as the material for the building’s facade or skin. The skin’s geometry took its cues from early design iterations harkening back to hexagonal forms developed as a biomimicry concept derived from bee’s honeycombs.

DETAILED PROJECT INFORMATION:

Site & Location: The Science Pyramid is located in the south central portion of the Gardens' York Street location. Defined by pools of water on the south and west sides, a depressed amphitheater to the northeast, and the El Pomar Waterway to the east, the building's site selection assures 360-degree sightlines when viewed from the rest of the Gardens. Designed to respond to its surrounding environment while bringing a sense of scale appropriate to the site without dominating surrounding elements, the building rests on a square geometric platform from which it rises nearly 34 feet to its ultimate shape of a pyramid. The Pyramid is also diagonally divided into two sections and pulled apart slightly to create a visual connection along a diagonal axis with the existing Four Towers water feature on the southwest corner. The Pyramid's entry from the El Pomar Waterway, leads visitors to and from the building along a tranquil pool of water defined by tall vertical walls on each side. At the entryway, the building's skin is raised, forming an eyebrow over the threshold along the east façade.

Major Design Features: Biomimicry was the dominant theme guiding the development and formation of the Science Pyramid's design concept. Like a form emerging from the earth, the building portrays a dynamic, spiraling movement that symbolizes how tectonic plates push upward to create something brand new—in this case, giving way to a building that holds new life and knowledge at the Gardens. To further the concept, its building envelope or skin, imitates nature by shielding itself with hexagonal-shaped honeycomb cladding designed to protect the interior from rain, snow and wind, as is the nature of a beehive. The interior space and exhibits inform visitors to see the world of plants through a scientific lens.

Architectural Specifics/Geometry: In response, Denver Botanic Gardens' request for an iconic Science Pyramid to showcase their science work and a number of broader concepts such as global climate change, the Burkett Design team responded with a pyramid that mixes glazed and opaque systems. Further, rather than propose a conventional four-sided pyramid structure, the form was split and tweaked to respond to the Gardens' circulation corridors, incredible surrounding landscape and daylight. Stretching the form also provided space for important functional requirements such as mechanical systems. Much like how the sides of a pyramid lean on each other allowing it to perform like a three-dimensional three-pin arch, the Science Pyramid’s faceted sides meet at the “spine,” a glazed ribbon of skylights cutting diagonally through the building’s footprint. The skin of the building derives its geometry from early structural concepts using hexagonal shapes derived from honeycombs to establish rigid diaphragms.

Envelope: The Pyramid's technologically advanced, high performance skin (façade), designed by Studio NYL, is clad in four-foot-wide hexagonal-shaped ventilated Swisspearl fiber-cement panels that mimic the geometric efficiency of nature's wax honeycombs. Thirty panels feature photovoltaic collectors tasked with gathering energy for interior exhibits. In addition, the central portion of the structure and multiple glass portholes are constructed of electrochromic glass, which adjusts in opacity from clear to 97 percent opaque throughout the day, based on solar intensity, or at the flip of a switch as the building's program requires. At sundown, the windows lighten to reveal the building's colorful interior exhibits and exterior flora nearby.

Structural and Enclosure Systems (4 Layers): The Science Pyramid has four layers to its structure and shell. The first layer, or primary structure consists of steel pipe elements which lean and balance themselves onto the “spine” of the building as noted above. The structure provides for a column-free interior to the “pyramid” and a primary structure that sheds all the vertical and lateral loads on it through flexure and axial loads through the pipe members. To avoid the costly and difficult to fabricate “fishmouthed” joints, the pipes with “T” and “K” intersections are square cut with simple “H” and “A” shaped connection elements, which saved considerable cost and schedule. The secondary structure is composed of six-inch hollow square structural shapes and six-inch light gage studs specifically arranged to meet the cladding systems geometry. It is also supported by slender rods to permit the ceiling to float over the primary pipe structural members. The final two layers make up the Pyramid’s technologically advanced skin (façade), designed by Studio NYL. A continuous layer of rigid insulation sits outboard of the secondary structure with an air barrier system directly adhered to it. The building is clad in four-foot-wide hexagonal-shaped ventilated Swisspearl fiber-cement panels that mimic the geometric efficiency of nature's wax honeycombs. They are mounted to a rail system held above the insulation and weather barrier with fiber reinforced polymer fasteners that thermally separate the outer skin from the interior structure.

Exhibits / Displays: The Science Pyramid's digitally interactive displays housed by the building were designed by Second Story/Part of SapientNitro, to foster a greater understanding of Colorado ecosystems and their similarities to others around the world. Featured exhibits highlight the Gardens’ recent work with the city of Ulaanbaatar, Mongolia in an effort to draw parallels between Colorado, Mongolia and Patagonia climates and landscapes. In short, this unique exhibit space showcases the Garden's forward-thinking mission and incredible global influence, while demonstrating how visitors can get more involved. The general contractor was the GH Phipps Construction Companies based in Greenwood Village, Colorado.

A blend of progressive design, sustainable technologies and biomimetic principles, this dynamic structure is designed to reflect its purpose - the advancement of botanical science. Resting on a square geometric platform, the structure rises over 10 meters into a pyramid form with 16 different faces, all clad with hexagonal-shaped ventilated Swisspearl fiber-cement panels that mimic the geometric efficiency of nature’s wax honeycombs.

Structural and Enclosure Systems (4 Layers):

The pyramid has four layers to its structure and shell. The first layer, or primary structure consists of 50 tons of steel pipe elements which lean on and support each other. This structure provides for a column-free interior to the “pyramid” and a primary structure that sheds all the vertical and lateral loads on it through flexure and axial loads through the pipe members. To avoid the costly and difficult to fabricate “fishmouthed” joints, the pipes with “T” and “K” intersections are square cut with simple “H” and “A” shaped connection elements, which saved considerable cost and schedule.

The secondary structure is composed of six-inch hollow square structural shapes and six-inch light gage studs specifically arranged to meet the cladding systems geometry. It is also supported by slender rods to permit the ceiling to float over the primary pipe structural members.

The final two layers make up the Pyramid’s technologically advanced rainscreen cladding, designed by Studio NYL. A continuous layer of rigid insulation sits outboard of the secondary structure with an air barrier system directly adhered to it. 492 hexagonal Swisspearl hexagonal-shaped plates are mounted onto a rail system held above the insulation and weather barrier with fiber reinforced polymer fasteners that thermally separate the outer skin from the interior structure.

Thirty panels feature photovoltaic collectors tasked with gathering energy for interior exhibits. In addition, the central portion of the structure and multiple glass portholes are constructed of electrochromic glass, which adjusts in opacity from clear to 97 percent opaque throughout the day, based on solar intensity, or at the flip of a switch as the building's program requires.

From an architectural perspective, Swisspearl's clean lines allowed the team to achieve a more modern, high-tech appearance while softening the building's visual impact within its setting.

More from the Manufacturer:

In July 2013, Denver Botanic Gardens' chief executive officer, Brian Vogt, held a competition asking design-build teams to conceptualize a transparent, iconic "Science Pyramid" that would not only fit neatly within the Gardens, but enhance botanical learning in an artful way. The eye-catching submission proposed by Denver, CO-based BURKETTDESIGN and Boulder, CO-based Studio NYL's Skins Group was what Vogt had been looking for and more. The dynamic structure proposed to house exhibits featuring the Gardens' conservation and research efforts, was a blend of progressive design, sustainable technologies and biomimetic principles designed to reflect the building's purpose—the advancement of botanical science.

One year later, on September 16, 2014, the Gardens' much anticipated new 5,258 square foot, $6 million Science Pyramid opened to the public, showcasing the innovative research being done at the Gardens on contemporary botanic and environmental issues. The structure, designed to respond to its surrounding environment, rests on a square geometric platform from which it rises nearly 34 feet to its ultimate shape of a pyramid. Constructed of 50 tons of tubular steel, 492 hexagonal Swisspearl© plates, and 16 faces (instead of the usual four), the pyramid, which is dropped into an existing pond, catalyzes an intriguing blurring of wall and roof elements.

DESIGN INSPIRED BY BIOMIMICRY The Science Pyramid's design, which is based on biomimicry, or the way plants and animals inspire innovation and actions in people, bisects the structure with a swath of glass. Windows and skylights are strategically positioned to focus on specific views, and the interior is like that of a shiny, white, angled igloo, filled with interactive displays and information about the climate and ecosystem in Colorado. One of several alcove areas houses the Gardens’ Omni-Globe, an illuminated sphere that presents the Earth as seen from space.

"To accommodate the aesthetic, functional and technical requirements of this extraordinary project, the form was split and manipulated," explains Ben Niamthet, BURKETTDESIGN's project designer. "We also determined that an all-glass pyramid (similar to the Pyramide du Louvre, I.M. Pei's glass and metal entrance pyramid at the Louvre in Paris) was impractical given the programmatic demands of a space featuring digital and projection exhibits."

The Science Pyramid's facade has four layers to its structure and shell. But it was the elemental theme of biomimicry that guided the development and formation of its conceptual design from the beginning. Like a form emerging from the earth, the building portrays a dynamic, spiraling movement that symbolizes how tectonic plates push upward to create something brand new—in this case, giving way to a building that holds new life and knowledge at the Gardens.

"To further the architect's vision, we designed a building envelope that imitates nature by shielding itself with a highly progressive cladding system designed to protect the interior from rain, snow and wind, as is the nature of a beehive," explains Christopher O'Hara, cofounder and principal of Studio NYL and The Skins Group explains. "The pyramid's roof takes its cues from a lot of the cold roofing projects you see in the mountains—and it offers greater thermal performance for the overall building."

As the first rainscreen of its kind in the U.S. (only one similar application predates it in China), the building's technologically advanced, high performance skin is clad in four-foot hexagonal-shaped, ventilated Swisspearl© fiber-cement panels that mimic the geometric efficiency of nature's wax honeycombs. Below the rainscreen, the roof features five inches of insulation, and custom photovoltaic panels, which make this one of the greenest designs possible.

SELECTION OF THE SWISSPEARL PRODUCT A traditional pyramid is essentially an angled form with four facets. In contrast, the Science Pyramid has two peaks and 16 facets—each with a different degree of slope. After extensive research, the design team determined that Swisspearl was the only product capable of providing a rainscreen system and warranty for sloping surfaces. Other systems imposed excessively rigid criteria and were limited to vertical applications only. The Swisspearl product was also adaptable to the Pyramid's wide array of architectural elements including ridges, valleys, peaks and overhanging eyebrows, as well as vertical, canted and sloped surfaces.

"We selected the Swisspearl product for a multitude of reasons. For starters, it offered a sustainable design solution that protects the structure's roof membrane from UV exposure while extending the lifecycle of the roof. It was also more affordable than metal composite rainscreen materials," explains Barton Harris, AIA, BURKETTDESIGN's principal in charge of the project. "Panels could also be cut in the field to meet extremely complex geometries, its finish consistency was flawless, and there are no visible color or surface variations from panel to panel—this is astounding given that the panels were neither supplied nor installed in batched packages."

From an architectural perspective, Swisspearl's clean lines allowed the team to achieve a more modern, high-tech appearance while softening the building's visual impact within its Garden setting and fits within the family of natural materials around it.

The company also factory-applied their F-Coating to the panels and cut edge, which provided a uniform finish while protecting the surface from scratches and darkening over time. This clear, matt finish will add years to the performance of the panels while keeping the building clean (it naturally sheds dirt when water is applied) reducing maintenance costs dramatically.

Additionally, the color of the Swisspearl fiber-cement panels is integral to the material, so scratches and damage are less apparent, and panels do not fade over time. Even though a dark grey hue was selected it remains vibrant with sharp reflections, which helps to emphasize the different angles and facets of the building.

PANEL DESIGN & INSTALLATION Because the rainscreen was designed to mimic the protective structure of a beehive, the honeycomb shape was paramount to the biomimetric design concept. The Swisspearl panels offered the flexibility to express this biomimicry, which required that each of the hexagonal panels needed to be viewed both as a whole, and individually.

To accomplish this, preciseness in panel size and the gap between panels were critical to visually communicate the concept of a honeycomb. The most effective use of the standard material sizing to minimize waste was to cut the four-foot hexagonal shapes from a standard four-foot-wide by 10-foot long panel. All full hexagonal shapes were laser cut precisely in the factory with client supplied CAD files, while field cuts were required for all partial hexagons (edge and ridge conditions) to meet the required complex geometries. With nearly 500 hexagonal panels on the Science Pyramid, there were over 1,500 joints, or adjacent planes on the building. Amazingly, all edge cuts were precise with no frayed edges or blade markings.

"Swisspearl's shop drawings and layout services were outstanding," adds Harris. "As the architect, we were very concerned about the level variation between hexagonal cladding panels—the Swisspearl product made this concern vanish. There was absolutely no cupping or warping within panels or between anchor points, insuring that adjacent panels appear aligned in plane."

Swisspearl's large selection of attachment options allowed the design team to select from a wide array of surface fasteners, and ultimately choose one that fit within their budget constraints. They selected a low profile rivet that demonstrates honest structural anchorage without becoming a focus in order to keep the fasteners from being so noticeable that the cladding would appear as a suit of armor. Further, Swisspearl's anchoring system avoided potential divots and warping of panels in areas adjacent to the fasteners. Changing from a concealed to an exposed fastener system also allowed the team to reduce the thickness of the cement-fiberboard, from 12mm to 8mm (the design team worked closely with Swisspearl's fabrication team to assess the capacity of a system using the non-traditional hexagonal shape to justify a thinner panel's structural adequacy - see stress diagram). Anchorage of partial panels was accomplished with gauged metal supports, rivets and VHB tape. Even though the number of partial pieces was substantial—all custom cut with some as small as one-inch by two-inches—Swisspearl offered an attachment solution for each of them.

The company also worked closely with Studio NYL's Skin's Group to contemplate a thermally broken sub-framing structure that would accommodate all required wind and snow loading. An overlapped series of hat channels, z-girts and fiberglass standoffs were used within the cladding system to provide adequate insulation, proper roof drainage and air circulation, and separation of rainscreen panels.

Joint width was determined by evaluating the airflow requirements of the rainscreen system's performance criteria as well as the scale and distance at which the gap could be perceived and the hexagonal panel defined. Because the Science Pyramid system required a larger gap than a typical rainscreen system to accommodate the curbs of the skylight, an analysis was performed to verify that there was adequate space to allow air to move behind the panel. Ultimately, it was determined that a one-inch gap, coupled with the dark color of the panel, would not only meet the system criteria it would be visible from across the amphitheater. Today, the shadow line created by the six-inch rain-screen stand off provides a dark contrast to the Swisspearl panels, accentuating the hexagonal form from a distance. (Incidentally, the first snow of the season has produced a striking contract between the one-inch shadow gap and the snow coated hexagonal panels.)

Swisspearl worked closely with the installers to insure that the panels were protected during installation. Watching the installation was like watching mountain climbers scaling steep slopes; the dramatically angled facets of the Science Pyramid created the most complex installation imaginable. Installers wore soft-soled footwear, and were careful to apply pressure at cantilevered panels. Also, because of the complexity of the installation, there was a tremendous amount of foot traffic on the cladding. As promised, it held up beautifully through the construction process.

ADDITIONAL DESIGN ELEMENTS Thirty of the roof panels feature photovoltaic collectors tasked with gathering energy for the interior space and exhibits, which inform visitors of the world of plants through a scientific lens. The air gap between the Swisspearl panels and the roof membrane also provides a shading and cooling effect, which reduces the heat gain within the building. In addition, the central portion of the structure and multiple glass portholes, are constructed of electrochromic glass, which adjusts in opacity from clear to 97 percent opaque throughout the day based on solar intensity, or at the flip of a switch as the building's program requires. At sundown, the windows lighten to reveal the building's colorful interior exhibits and exterior flora nearby.

The Science Pyramid's digitally interactive displays within were designed by Denver Botanic Gardens' staff and Second Story, part of SapientNitro, to foster a greater understanding of Colorado ecosystems and their similarities to others around the world. Featured exhibits highlight the Gardens’ recent work with the city of Ulaanbaatar, Mongolia in an effort to draw parallels between Colorado, Mongolia and Patagonia climates and landscapes.

"Connecting people to the science at the Botanic Gardens is really important," says Denver Botanic Gardens' CEO Brian Vogt, noting that employees work on everything from genetics to conservation. "A lot of people had no idea we were doing that." Before the pyramid, science "didn't really have a place" at the gardens, now "it's drawing people in droves."

The Science Pyramid, located in the Denver Botanic Gardens, is a pyramid-shaped building. Onyx Solar has integrated hexagonal crystalline silicon photovoltaic glass units with a 100% custom-made design.

This pyramid shows visitors the principal ecosystems of Colorado and explores similar environments around the world. The illumination and vibrations within the pyramid are determined by the current weather conditions.

The building has been awarded as the Best Project in Colorado in 2015 by the most significant construction magazine worldwide, Engineering News-Record (ENR), of the McGraw Hill and Standard & Poor’s group.