2025 West Best Projects
Award of Merit, Government/Public Building: Presidio Building 643 Rehabilitation Project
Presidio Building 643 Rehabilitation Project
San Francisco
Award of Merit
Submitted by Herrero Builders
Owner National Park Services
Lead Design Firm Siegel & Strain Architects
General Contractor Herrero Builders
Civil Engineer Provost & Pritchard Consulting Group
Structural Engineer Wiss, Janney, Elstner Associates Inc.
MEP Engineer Interface Engineering
Structural Engineer Bluestone Engineering
First built in 1923, this 20,000-sq-ft building originally served as two airplane hangars for Crissy Field. Today, it contributes to the Presidio’s status as a National Historic Landmark, representing a rare and cohesive collection of military architecture, planning and design spanning more than two centuries of U.S. defense history.
A $28-million rehabilitation project demolished the unreinforced masonry portions of the building; abated hazardous materials; replaced the roof, windows and doors; and upgraded MEP and fire systems.
The building also underwent extensive seismic retrofitting through a hybrid solution of structural steel integrated with the heavy timber framing. Permeation grouting stabilized soil underneath the foundation to remedy weak and unstable ground conditions.
The process involved injecting a formulated grout into the soil to create a solid, reinforced base that increased the soil’s bearing capacity, preventing potential settlement and providing additional support for the building’s structural integrity.
Historic wood elements such as windows, doors and skylights were carefully rehabilitated to preserve the building’s original historic appearance. After three years of construction, the project was delivered on time and $400,000 under budget in May 2024.
