Building in the Tropics: HOK Finds Design Inspiration in Nature
Metropolis’s Susan S. Szenasy talks to HOK architects about the climate-specific design for the National Oceanic and Atmospheric Administration.
National Oceanic and Atmospheric Administration (NOAA) Inouye Regional Center links two World War II-era, adapted airplane hangars with a new steel and glass building.
Courtesy Alan Karchmer
For the past three years Metropolis’s publisher and editor in chief Susan S. Szenasy has been leading the Think Tank program, a series of discussions with industry leaders on key issues surrounding human-centered design. On February 24, 2016 she talked to the architects and engineers at HOK who renovated the historic airplane hangars for the National Oceanic and Atmospheric Administration in Pearl Harbor, Hawaii. The conversation took place at HOK’s San Francisco office. What follows is an edited transcript of the conversation.
Susan S. Szenasy, publisher & editor in chief, Metropolis (SSS): It seems that we’re all trying to understand what it means to build in the 21st century, to build within the environment and with humanity at the center of it. This project by HOK personifies the new thinking.
Kyle Prenzlow, HOK, project architect (KP): The site of the National Oceanic and Atmospheric Administration (NOAA) is about 35 acres, comprised of six buildings. The main building houses about 800 staff, and supports all of NOAA’s operations throughout the Pacific region. It was the vision of NOAA to bring all of their groups together in one facility so that they could collaborate and, most of all, be efficient, share research, and also save operations costs. Since it’s on a historic site in Pearl Harbor, which is an active military base, the Navy is essentially the owner, NOAA was the tenant. We took the hangars, which were designed by Albert Kahn, down to the bones and restored them. We inserted a new structure between the hangars that joins them into a single structure. NOAA’s research vessels are housed here. We treated the design of the project like it was a university campus with quads. The footprint of the building is three-and-a-half acres, so we really needed to look for strategies to make neighborhoods and break up such a large space, while making autonomous groups feel part of a whole. The monkey pod tree was an inspiration for some of the daylighting strategies and the natural ventilation. It’s a native Hawaiian species and it influenced the design of some of the daylight requirements.
SSS: HOK has been exploring biomimicry and biophilia for some 15 years. Your practice is looking at ways a building can learn from its natural environment and the interaction between the two. Let’s talk about what you found in the Kahn building that was really interesting to you and how he related that building to that environment that it was built in.
Zorana Bosnic, RIBA LEED AP BD+C, vice president, senior project manager, HOK (ZB): There was an opportunity to bring the breeze as well as light into the hangars. There was also the ability merge indoor and outdoor spaces. It was very transparent and very accessible. Early on, we looked at historic and natural contexts of the island and the monkey pod tree was one of the inspirations. It’s a single trunk tree that has a very dense top layer canopy and provides really good shade and thermal comfort during the hot humid days. Then when it’s overcast and raining, the leaves curl up into a narrow, conic shape and allow the breezes and rain to reach the ground. The grass is literally greener under the monkey pod tree because it allows the rain to reach the soil.
Panoramic views and natural lighting and ventilation make the dining room into a revitalizing space.
Courtesy Alan Karchmer
In 2000, the conversation about the interaction between design and the natural world asked “How can innovation in the built environment be inspired by nature?” One interesting aspect to the biomimetic approach was the focus on performance. There is 3.8 billion years of natural world around us. What can we learn about these processes and how can we translate that into our buildings and make them better performing? That evolved slowly into human-centric design. What does it mean to the people occupying the building? Learning from Albert Kahn and nature, our challenge was going from a big aircraft hangar to becoming a home for 800 people. How can we bring that to a single occupant? How can we assure that the daylight, the breezes, the view toward the outside, and nature are brought in? How can we create the spaces of nature within these neighborhoods?
SSS: You can really make buildings not just more efficient but more hospitable to the people, connecting people to their circadian rhythms and to their surroundings. What natural conditions did you want to exploit on Ford Island?
KP: The climate, except for the humidity, is ideal. This is the first building I’ve worked on where we were not really worried about the temperature difference between inside and outside. We wanted to blur the line between the outside, which is so comfortable, and the inside of the building by bringing the natural environment into the building and vice versa.
SSS: How did the monkey pod tree’s behavior influence the way you utilized the structure and the roof of the building?
KP: The hangars act as a large canopy, opening up and bringing light in. It allows controls for temperature and provides a cooling environment and stack effect. We could take an entire 12 feet of truss space to let a hot bubble build at the top of the space to drive this ventilation system.
The Atrium / Exhibit hall at the NOAA Inouye Regional Center
Courtesy Alan Karchmer
Todd M. See, PE LEED AP BD+C senior vice president WSP | Parsons Brinckerhoff (TMS): The cooling system takes advantage of trade winds. We’re bringing 100% outside air into this building as opposed to a traditional commercial building using 20%. We designed a system that could capture the trade winds and move the air down through the building. After the air’s cooled, it just falls due to gravity, moves out through a raised floor system, and then the heat within the space naturally wants to rise. The heat rising through the space pulls the cool air in behind it and then the warm air escapes by natural ventilation through louvered penthouses distributed around the building. It’s really simple. We started with the idea that the trade winds are very consistent, move consistently across the building, almost perpendicular but then you’ve got a condition where for part of the year, the winds come from the opposite direction, the Kona winds. We had to design the system to accept that condition, and then the winds don’t always blow. The system can actually operate without any wind at all and it’s the gravity of the cool air falling down through the building and the buoyancy of the warm air rising up and out. It feels very much inside as it does outside, while maintaining a consistent temperature for all the occupants.
SSS: How does it feel to be inside? What do you compare it to?
TMS: It’s more comparable to being in a park than an office space. The way the air feels and the way it smells within the building, the quality of the light. Jay and his team spent a ton of time modeling the daylighting. Everybody in the building really enjoys being in the space.
SSS: Jay, your job as a lighting designer was to go against everything that’s been believed about modern lighting. We have to have 50 foot candles on every desktop or floor. We have to have 65 degrees at all times. How did you use these amazing givens of the island, incorporate them, and convince people within the building that the lower standards are better and more interesting?
Jay Wratten IALD, C, MIES, lighting design, WSP | Parsons (JW): We wanted an artificial lighting system that didn’t have to be on. The building was designed to be naturally lit. So the real challenge was that the lights that people need and the lights that airplanes need are quite different. The strategies were, how do we let as much natural light into the space while also creating a quality of light that is nice to be under? One of the challenges was the new floor, which significantly changed the geometry of the space. We created a canopy of additional skylights. All of the skylights were added to allow a more even amount of light and allow more people to work without artificial light for more of the day. A lot of energy was put into how to control the light so that it never hits you directly, but reflects and bounces and glows in a more uniform way. We ended up mocking up diffusers so the light diffuses through these elements and reflects up onto the ceiling. What you tend to get with skylights is really bright holes and really dark ceilings. The reflectors bounce that light back up and create a softer environment. The space is very dynamic because the light level can change by an order of magnitude with cloud cover.
SSS: You had to sell that idea because people want those 50-foot candles.
JW: The 50-foot candles were a problem because we had this set of goals, both from a ventilation and lighting perspective to connect to the outside. They wanted a highly efficient building. We had the owner come in and we brought a light meter and set it on the table, closed the blinds, lowered the light level, and basically asked, does this feel good? Can you read? We kept adjusting the light level until we got to a point where they said, “This feels good”. It was lower than the recommended target. Through that, we were able to relax the goals and by relaxing the goals, we could naturally light more of the space. We wanted a building that had to work as little as it had to.
ZB: Another aspect that drove the conversation is water because it’s surrounded by water. There is an amazing kind of humidity that you can harvest.
TMS: One of the largest sources of greywater was the condensation because as we’re cooling the air, we’re taking all the condensate out, so on some days we can capture 10,000 gallons. In most projects, you would just throw it away, but here we were able to reuse it to irrigate the 35 acres of site. The greywater then goes back into the building to be used to flush toilets and for non-potable uses.
A series of interactive exhibits in the 3-story atrium public space highlights the history of the island and region as well as NOAA’s diverse mission.
Courtesy Alan Karchmer
SSS: Your entire team is really keyed into examining every part of the building as you build, design, and work together. It’s not like you toss the drawing over to the engineer over a partition.
JW: On the lighting side we did a lot of computer modeling but then we went out to see the space. We had to build physical models for the skylights because we wanted to focus on the quality of light. It’s one thing for the computer to say what it’s like, but it’s another to say, “Yes, but it actually feels like this.”
SSS: If it feels right to you, there might be some slight differentials with other people but that feeling of rightness is intuitive. It’s like biomimicry inside you because what you relate to, we relate to. It’s really interesting that we’re talking about feeling and not just metrics, which has been the mantra for years.
JW: We start by creating specific goals and then evaluating how to achieve them. We debate amongst the design team, the owners, and the occupant; then we work really hard to come up with what appears to be a very simple solution. What could be more simple than using daylight to light a space? But it’s amazing how much time you have to take to get to that solution. It all does ultimately distill down to how does it feel and how do people feel within that space?
SSS: I’m really glad we got to that because when talking about designing for people, feelings are sort of indefinable and maybe scientific terms don’t apply. This is a great moment for science but I’m so glad that our humanity and our feelings are reemerging.
TMS: An important point that differentiates this project is that it’s a government project. It takes an act of Congress to pass the budget. That money is available for one fiscal year and it has to be awarded every year. We set hard goals early on: 100% outside air, reclaimed water, natural daylight. The HVAC system of the building overall uses 40% less energy than a typical commercial office building. You can take that number and very quickly work through a payback analysis that says the sum total of the whole design is extremely efficient.
SSS: I’m really glad that the Navy is the landlord. This building feels like a turning point, it could influence their other renovations. This is a really wonderful project and thank you for sharing it with us.
Susan S. Szenasy (background, left) fields a question from the expert panel.
Photo Courtesy Gene X Hwang/Orange Photography
HOK: Zorana Bosnic, RIBA, LEED AP BD+C, vice president, senior project manager; Kyle Prenzlow, LEED AP, senior associate, project manager
WSP | Parsons Brinckerhoff: Todd M. See, PE, LEED AP BD+C, senior vice president; Jay Wratten, IALD, LC, MIES, lighting design
Moderator: Metropolis, Susan S. Szenasy, publisher and editor in chief.
The Metropolis Think Tank series is presented in partnership with ASID, DuPont Surfaces, Sunbrella, Teknion, and USG.