Mass Timber Anchors a New Era of Campus Design: Exposed Wood Structures in University Building Construction

The emergence of mass timber as a primary structural system in campus architecture represents one of the most significant material shifts in educational building design in decades. Projects such as Studio Gang’s new building at the California College of the Arts (CCA) in San Francisco demonstrate how exposed cross-laminated timber (CLT) and glued-laminated timber (glulam) can define both the structural logic and the aesthetic character of contemporary university buildings. As more institutions pursue ambitious sustainability targets and distinctive architectural identities, mass timber offers a convergence of structural performance, environmental responsibility, and experiential quality that traditional steel-and-concrete assemblies cannot match. This article examines the design principles, material specifications, code considerations, and sustainability outcomes that building professionals must understand when specifying mass timber for campus construction projects — drawing on recent precedent including the CCA project and other pioneering mass timber construction projects across North America.

Structural and Spatial Design Principles for Mass Timber Campus Buildings

Exposed Timber as Architectural Expression

One of the defining features of the CCA building by Studio Gang is the decision to leave the mass timber structure exposed. The two pavilions that house classrooms, art studios, and exhibition galleries are among the first exposed mass timber structures in California. This approach goes beyond aesthetics — exposed wood surfaces contribute to occupant well-being through biophilic design principles, improve indoor acoustic performance through natural sound absorption, and eliminate the need for ceiling finishes, reducing both material costs and embodied carbon.

Key spatial advantages of exposed mass timber in campus buildings include:

• Clear spans and column-free studios — Glulam beams and CLT floor panels can achieve spans of 12 to 18 meters, providing flexible studio and classroom spaces that accommodate evolving teaching modalities
• Reduced structural depth — Mass timber panels serve as both structure and finished ceiling, saving 300 to 600 mm of floor-to-floor height compared to steel-concrete composite systems
• Warmth and texture — The natural grain and color of timber create a tactile environment conducive to creative and collaborative learning
• Prefabrication precision — CNC-machined timber components arrive on site with tight tolerances, enabling faster enclosure and earlier interior work

Pavilion Planning and Landscape Integration

The CCA building organizes its program into two distinct mass timber pavilions set on a robust base. A green terraced landscape unites the lower and upper levels, creating an indoor-outdoor learning environment that strengthens connections among varied people, ideas, and creative practices. This pavilion approach offers several advantages for campus design:

1. Multiple smaller volumes relate more comfortably to the human scale of existing campus fabric than a single monolithic block
2. Terraced green roofs and planted interstitial spaces manage stormwater, reduce heat island effects, and provide informal gathering areas
3. The separation between pavilions allows natural light and ventilation to reach deeper into the building plan
4. Future expansion is simplified — additional pavilions can be added without disrupting occupied space

Mass Timber Material Specifications for Educational Buildings

CLT and Glulam Performance Requirements

Specifying mass timber for campus buildings requires careful attention to material grades, connection design, and moisture management. The two primary engineered wood products used in projects like the CCA building are CLT and glulam, each with distinct performance characteristics.

Building professionals should reference the CLT Handbook published by FPInnovations and the ANSI/APA PRG 320 standard for CLT, while glulam specifications follow ANSI A190.1. For projects requiring enhanced acoustic separation between classrooms or studios, specify CLT panels with acoustic toppings such as resilient channels, sound-damping mats, or floating concrete screeds that add mass without compromising the exposed timber ceiling below. Detailed mass timber material specifications and CLT and glulam performance data from projects like the Catalyst Building in Spokane provide additional reference for specifiers.

Moisture Management During Construction

Mass timber is susceptible to moisture damage during the construction phase, particularly in climates with significant precipitation or humidity. Essential moisture management strategies include:

• Just-in-time delivery sequencing — Coordinate fabrication and delivery so that timber components arrive only when the building enclosure is weathertight or within 48 hours of planned installation
• Protective wraps and breather membranes — Cover stored panels with waterproof but vapor-permeable sheeting, with ventilation gaps to prevent condensation
• Daily moisture monitoring — Use pin-type moisture meters on delivered panels and at three-day intervals until the building is enclosed; reject any panel with moisture content exceeding 16%
• Rapid enclosure strategy — Sequence the construction schedule to close the roof and exterior walls within two to three weeks of the first timber delivery

Building Code Compliance and Fire Safety for Mass Timber Campuses

Tall Mass Timber Provisions in the IBC

The 2021 and 2024 editions of the International Building Code (IBC) introduced new tall mass timber provisions under Types IV-A, IV-B, and IV-C construction, permitting exposed mass timber buildings up to 18, 12, and 9 stories respectively. These provisions have opened the door for mass timber campus buildings — including the CCA project — that were previously limited to six stories under the old heavy-timber (Type IV-HT) classification. The tall mass timber provisions adopted by NFPA provide the fire safety framework that enables these taller exposed timber structures.

Key compliance requirements for Type IV-C buildings (the classification most applicable to mid-rise campus buildings):

• All mass timber elements must achieve a minimum 2-hour fire-resistance rating
• Non-combustible protection is required on mass timber surfaces in exit enclosures and shafts
• Fire sprinklers must be provided throughout in accordance with NFPA 13
• An automatic fire alarm system must be installed
• Exposed timber surfaces are permitted in occupied spaces, but concealed spaces must be sprinklered or protected with non-combustible materials

Char Layer Performance and Fire Engineering

Mass timber exhibits predictable charring behavior under fire conditions. The char layer forms at approximately 0.6 to 0.8 mm per minute, insulating the remaining structural section and maintaining load-bearing capacity for the required fire-resistance duration. For CLT panels, the structural designer must account for the sacrificial char depth plus a zero-strength layer when calculating the effective cross-section. The following fire engineering considerations are critical for campus buildings with exposed mass timber:

1. Verify that connection hardware is fire-rated or encapsulated — steel connectors can transfer heat into the timber core if not protected
2. Model the fire scenario for each unique occupancy type (art studios, lecture halls, exhibition galleries all have different fuel loads)
3. Coordinate firestop details at penetrations through CLT floor and wall panels with the fire protection engineer
4. Specify intumescent coatings only where required — exposed charring is acceptable aesthetic in most Type IV applications under the IBC

Passive Design Strategies and Sustainability Outcomes

Self-Shading Facades and Night-Flush Ventilation

The CCA building incorporates two passive design strategies that significantly reduce mechanical system loads. Self-shading facades are achieved through deep window recesses, overhangs, and vertical fins that block high-angle summer sun while admitting low-angle winter light. Night-flush ventilation uses motorized windows or dampers that open automatically when exterior temperatures drop below interior setpoints, cooling the exposed mass timber structure overnight so that it acts as a thermal battery the following day.

These strategies deliver measurable performance benefits:

Embodied Carbon and Net-Positive Infrastructure

The CCA building is designed with infrastructure for a closed-loop, net-positive energy future. This forward-looking approach recognizes that campus buildings constructed today must be capable of connecting to district geothermal loops, photovoltaic arrays, and battery storage systems as these technologies become cost-effective at scale. Mass timber plays a central role in embodied carbon reduction — a cubic meter of CLT stores approximately 1.0 to 1.2 tonnes of CO2 equivalent, compared with steel which emits approximately 1.8 tonnes of CO2 per tonne produced and concrete which emits approximately 0.9 tonnes of CO2 per tonne.

Building professionals evaluating mass timber for campus projects should consider the full lifecycle carbon impact:

• Material extraction and manufacturing — Sustainably harvested timber has the lowest embodied carbon of any structural material when sourced from certified forests
• Transportation — Regional fabrication facilities reduce logistics emissions; specify locally manufactured CLT where possible
• Construction phase — Lighter components reduce crane and equipment emissions; prefabrication reduces site waste and rework
• Operational phase — Exposed timber improves thermal performance and enables passive strategies that lower operational carbon
• End of life — Mass timber can be deconstructed and reused or used as biomass fuel; it never requires landfilling in the manner of steel or concrete debris

Recent updates to wood construction standards from the American Wood Council continue to expand the design possibilities for mass timber in campus and institutional applications, while updated methodologies for calculating carbon stored in wood products help project teams document their sustainability claims with greater rigor.

Conclusion

Mass timber is fundamentally reshaping how campus buildings are conceived, designed, and constructed. Projects like Studio Gang’s CCA building in San Francisco demonstrate that exposed CLT and glulam structures can achieve a rare synthesis of structural efficiency, architectural warmth, fire safety compliance, and carbon performance that aligns directly with the sustainability commitments of leading educational institutions. For building professionals, the shift toward mass timber on campus requires updated knowledge of material specifications, code provisions under the IBC tall mass timber categories, passive design integration, and moisture management protocols. As more universities adopt ambitious embodied carbon targets and seek distinctive architectural identities for their campuses, mass timber will continue to anchor a new era of educational building design — one that prioritizes both human experience and environmental responsibility.