Historic Trefethen Winery

Category: Work
Napa, CA

The historic Trefethen winery structure was originally constructed in 1886 by Hamden McIntyre, a Scottish ship captain and well-known architect of wineries in the Napa Valley. This 3-story, 18,000 square foot structure was severely damaged during the South Napa Earthquake on August 24, 2014 leaving the structure resting in a precarious tilt, with the second and third story shifted approximately four feet.

When determining the structural approach for repair and retrofit of the historic structure extensive coordination with the owners and historic architect was critical to ensure new elements improving resiliency of the structure did not detract from the building’s character historic fabric. It was important to the Trefethen family to save as much of the existing framing as possible, maintaining the historic feel of the structure. Exterior elements including the straight sheathing and historic windows were repaired and reinstalled to the original aesthetic.  Historic mortared stone foundations were also retained and utilized in the repair and retrofit.

Positive connections between existing beams, posts and foundations were provided and bolted steel side plates were added as required at floor beams for additional strength.  Where possible, damaged or split framing members were revived with color-matched injected wood epoxy and bolted steel side plates.  The majority of the framing members were able to be preserved with very few requiring complete replacement. With the addition of two strategically placed and connected 2-story bolted-connection steel moment frames, the building has not only survived, but been made stronger to continue as a piece of living history of winemaking in Napa Valley.

As a final tribute to the earthquake that rocked the structure, additional steel gravity framing was provided so that a single ‘Remembrance Post’ could be left in its deflected state to illustrate the magnitude of the event the structure withstood.

Photo Credit: Adrián Gregorutti, Courtesy of Trefethen Family Vineyards

Size 18,000 sf
Completed 2016
Architect Taylor Lombardo Architects
Contractor Facility Development Corporation
Owner Trefethen Vineyards
Design Award – Durable & Adaptable Wood Structures

WoodWorks, 2021

Excellence in Structural Engineering - Award of Merit - Historic Preservation

Structural Engineers Association of Northern California (SEAONC), 2017

Excellence in Structural Engineering - Award of Merit - Historic Preservation

Structural Engineers Association of California (SEAOC), 2017

Design Award - Rehabilitation

California Preservation Foundation, 2017

Award of Merit - Post South Napa Earthquake Restoration

Napa County Landmarks, 2015