NOAA Daniel K. Inouye Regional Center, Honolulu
Adaptive Reuse for Hawaii Hangars
Nature inspired the transformation of twin World War II-era airplane hangars in Hawaii into a high-performance office headquarters.
The hangars, which narrowly escaped destruction in the 1941 attack on Pearl Harbor, have recently been reimagined, stripped to their bones, restored, and linked by a new steel-and-glass pavilion to create a high-tech, environmentally sensitive research, educational and office campus.
The new Daniel K. Inouye Regional Center consolidates 715 employees who had been spread out among multiple Oahu locations. The campus supports the National Oceanic and Atmospheric Administration (NOAA), which monitors the Pacific Region’s climate, weather, oceans and coasts.
The hangars’ location on Ford Island in Pearl Harbor, where much of the U.S. Navy’s Pacific Fleet was anchored during the 1941 Japanese attack on Pearl Harbor, meant the design also needed to respect this U.S. National Historic Landmark site.
Designed through the twin lenses of sustainability and historic preservation, the Inouye Regional Center demonstrates contextual, high-performance solutions to modern design challenges. The sustainable approach created an attractive, healthy space that makes people want to come to work.
How do you make a large aircraft hangar feel like a comfortable home for more than 700 people, many of whom are coming together for the first time? One way is to bring the stunning natural surroundings into the space. The original aircraft hangars inspired beautifully simple, bioinspired design solutions for how the new Center could capitalize on Ford Island’s three primary natural resources: air, light and water.
To break up the scale of the 350,000 square foot, three-and-a-half acre facility, the design organizes the interior environment around principles of campus planning. There are central gathering spaces (including a three-story atrium that links the front door to the waterfront), interior quadrangles and team neighborhoods, a program-intensive workplace and primary and secondary circulation routes that clearly direct people through the Center’s generous spaces. Large expanses of glazed glass in the front and back blur the lines between the interior and its natural surroundings.
The Center’s circulation path helps unite the historic airfield, hangars and ocean waterfront into a unified campus.
Bioinspired Building Systems
The team looked to local biological influences to guide the design of the Center’s ventilation and lighting systems. The native single-trunk monkeypod tree (albizia saman) has a broad canopy that provides shade and thermal comfort during hot, humid days. When it’s overcast and raining, the leaves curl up into a narrow, conic shape that allow breezes and rain to reach the ground. The trees also protect themselves from the heat by pulling soil moisture through the vascular structure into their leaves. Excess moisture is released as water vapor, keeping the ecosystem balanced in a complete, integrated cycle.
Hawaii’s First Hydronic Passive Cooling System
Most of the building is cooled and ventilated without the use of mechanical fans. Emulating nature’s design, the Center’s hydronic passive cooling system—the first of its kind in Hawaii—pulls cool water from a 1,300-foot deep well under the sea bed and pumps it up into roof top cooling coils. The prevailing trade winds pass over these cooling coils and create natural ventilation. The weight of this cooled air drops the fresh air supply into vertical risers that move the air down through the building and into a raised access floor system.
As that air draws heat from the people and equipment, its temperature rises and it becomes buoyant. It then rises up through the building’s open spaces—which act as “lungs”—through interconnected light wells and atria before entering louvered penthouses and naturally exhausting into the atmosphere.
The underfloor air distribution system enables occupants of offices and workstations to enjoy fresh air and adjust floor diffusers to control the temperature around them to suit their comfort.
Skylight Diffuser System Draws in the Daylight
Because the open floor plates of the existing hangar structures were 700 feet long and 250 feet wide, deciding how to fill these voluminous interior spaces with natural light was another design challenge. A building occupant, for example, could sit as far as 125 feet away from a window or clerestory. The design team supplemented their building information model, which analyzed how the sun would move across the structure, with on-site visits and physical models of the skylights to enable them to experience the quality of light at different times of day.
The team’s design solution drives daylight deep into the building using specially crafted light lanterns that capture and reflect sunlight down into the space without electric lighting.
The design solution was a skylight diffuser system (Figure 1) that features a grid of apertures sprinkled across the roof, virtually eliminating the need for electric light during the day. Under this canopy of skylights, lucite diffusers were designed to act as light lanterns, capturing and directing the sunlight down into interior courtyards and workstations.
Below these devices are translucent reflectors that diffuse the natural light and glow like a light fixture during the day. Acting like a luminaire, this hardware creates a soft, pleasant environment by reflecting light back up to the ceiling. When clouds cover the sun, the interior space takes on a completely different feeling: ambient, glowing light from diffuse sources still powered by the sun. This natural cycle of illumination provides a consistent spread of 30 lux per square foot across the sprawling floor plates. The floor plates feature translucent partitions, bringing light where little came before and reducing electrical lighting loads by half.
Waste Not a Drop
The roofs of the hangars and central addition capture rainwater and distribute it to bioswales. Passive cooling units on the roof capture up to 10,000 gallons a day of condensate from the chilled coils of water, recycling it into a graywater system used to flush toilets and irrigate the 35 acre site’s native landscaping. No stormwater or graywater leaves the site (Figure 2).
First-Cost and Operational Savings
The adaptive reuse of the hangars and sustainable design features led to both cost and operational savings for NOAA. Construction costs for the new Pacific headquarters came in at $435 per square foot. By comparison, the cost to construct a typical research and administration building averages between $500 and $750 per square foot.
Meanwhile, the consolidation into the new space saves NOAA approximately $3 million per year in operational costs, $415,000 in energy costs (the energy model predicts 32.7% cost reduction below the ASHRAE Standard 90.1-2007 energy code) and $8,300 in water costs. •
About the Authors
Paul Woolford, AIA, LEED AP, is a senior vice president and design principal in HOK’s San Francisco studio and was the project’s lead architectural designer.
Todd See, P.E., LEED AP, is a senior vice president in WSP’s San Francisco office and was the project’s lead mechanical engineer.