Hangar One

2026 Design Award Recipient-Honor

Hangar One is one of the Bay Area’s most recognizable landmarks and largest freestanding metal structures in the world. The project rehabilitated the existing structure to create a higher performing space with flexibility for a range of modern uses while allowing it to recapture and continue its historic legacy. The iconic structure is listed in the National Register of Historic Places and was constructed in the 1930’s to house a dirigible for the U.S. Navy. The current project started with the existing metal frame as the skin was previously removed as part of a hazardous materials mitigation program. The project team went to exceptional lengths to rehabilitate Hangar One in a way that respected the visual characteristics of the original building while simultaneously improving past deficiencies. A new, modern façade and roof were designed to improve thermal performance and interior comfort, while maintaining similar apertures and weight as the historical ones. Structural upgrades were carefully designed to minimize their visual impact, while the concrete floor slab, concrete stem wall, and rolling “clamshell” doors at each end were retained and repaired. A performance-based passive ventilation strategy was implemented which significantly contributed to an energy and material-efficient design. A historical vent at the roof ridge was reimagined to be operable to adjust air flow and fresh air intake louvers were added at the structure base to take advantage of a natural heat stack effect. The result is a renewed modern landmark that restores its significance to the local community.

//jury comments

An incredible and iconic structure, beautifully handled, retaining the best of the historic fabric and legacy while introducing modern uses and structural upgrades that feel worthy of what came before.

//framework for design excellence measures

Measure 1: Design for Integration

The goal of the Hangar One project was to retain the existing historic features as much as possible to preserve its historic legacy while simultaneously achieving a sustainable strategy of reuse. A part of this strategy was to improve on the historical design to create a new, modern enclosure that would both protect and significantly extend the structure’s lifespan. Hangar One was constructed between 1931-1933; however the siding, windows, doors, and interior partitions were removed in 2010-13 because the coatings were leaking toxins. Therefore, the design team started with an existing steel frame, one of the longest spanning ones in the world, and a bare, concrete floor slab and stem wall. The original enclosure was designed primarily to house a dirigible, and was so large that it would “rain” inside from condensation build up, while the new enclosure needed to be designed for modern use and occupancy. The design team blended the efforts of historic design with a sustainable approach of reuse and minimalism to achieve a high performing space that restores the inspiration of its civic scale, quality of space and historic legacy.

Measure 2: Design for Equitable Communities

Yes, the Hangar One design was presented to the community at the end of the schematic design process. The project team learned what historical features were most important to the community and considered to be retained or accentuated in the final design.

Measure 3: Design for Ecosystems

The project abated hazardous materials on the existing structure creating a longer-term protection solution to the surrounding land and groundwater. The project aligned with bird-safe design guidelines such as low glazing to surface ratios, low glazing reflectance and low exterior lighting. In addition, the desire to achieve the aesthetic of a historical corrugated glazing used at the topmost window tier resulted in a fritted pattern design that aligned well with creating a bird safe condition at these higher risk locations. Concrete adjacent to the building exterior was removed and replaced with permeable gravel compatible for migratory birds.

Measure 4: Design for Water

Water consuming systems are limited within the Hangar One renovation. Water use is limited to interior restrooms which use low-flow plumbing fixtures meeting CALGreen and EPA Water Sense requirements. The project does not include landscape or other process water uses.

Measure 5: Design for Economy

The project strategy of reusing the existing historic features as much as possible while minimizing new deviations resulted in a very efficient construction of one of the largest structures by volume in the world. The project team often lauded what is “not seen” in the final built solution. For example, a code compliant natural ventilation strategy was used to avoid large ductwork, existing historical stairs were modified to create code compliant access to the mezzanine and roof instead of building new ones, and the existing structural steel was strengthened with individual selective members instead of creating new lateral systems.

Measure 6: Design for Energy

A passive ventilation system significantly contributed to an energy and material efficient design. The team used a motor operated ridge vent at the roof with fresh air intake louvers at the structure base to take advantage of a natural heat stack effect. In order to demonstrate code compliance, both Building Energy Simulation and Computational Fluid Dynamics were used to determine the expected interior ventilation effectiveness using such a natural ventilation system, measured over an entire meteorological year, with varying weather patterns, to achieve the required accuracy level. The result was a code compliant, energy efficient and historically compatible solution.

Measure 7: Design for Well-Being

Various analyses were undertaken to design the structure whose historical use was to house a dirigible for new modern purposes. These included thermal comfort, acoustic considerations, daylighting and glare. The result of these analyses was a design that increased the envelope performance while being compatible with the historical character defining features, including strategic additions of roof insulation, fritted glazing on the topmost tier to reduce glare and protect birds, confirming daylighting autonomy using existing apertures and designing new artificial lighting but retaining historical locations to achieve desired lux levels and color temperature.

Measure 8: Design for Resources

The project reused the extensive steel structure, perimeter concrete stem wall and majority of the concrete floor slab. The design intent was to maintain the historical loads on the steel structure and to not add new ones, significantly informing the new façade design, and reducing the amount of new reinforcement needed. Thousands of bolted steel members located throughout the structure were strengthened and added as part of the rehabilitation process. Additionally, the concrete stem wall at the base was retained and repaired using historically compatible materials and methods. Above embodied carbon results are estimated by architect and confidential.

Measure 9: Design for Change

Hangar One is designed for a flexible range of uses, allowing for changes of use over time without the need for future impactful upgrades. The façade and steel systems largely consist of bolted connections which can be disassembled and recycled if needed. At a smaller scale, any new work was carefully connected to the historic steel through clamped connections to avoid damage to it.

Measure 10: Design for Discovery

The true delight in Hangar One was experienced by the project team during construction. A unique construction methodology was used to carefully sequence the work in a largely horizontal manner, instead of a more traditional vertical one, in order to allow for the efficient use of scaffolding to be used on only a portion of the structure at a time. This sequence was incorporated into the design through modular material methodologies and utility routing strategies and required a higher level of teamwork during the construction phase of the project.