Project Experience

  • Trefethen Family Vineyard – 2017 Awards Winner!

    On August 24, 2014 the 3-story, 18,000 square foot historic barn structure of the Trefethen Winery was severely damaged during the South Napa Earthquake. The was left resting in a precarious tilt, with the upper floors rotating out of plane approximately four feet to the west. The severely damaged building was temporarily shored before straightening, […]

  • St. Eugene’s Baldacchino Sculpture – ENR California’s Best Projects 2017

    Preliminary analysis determined that a base isolation system was the best option to reduce the imposed seismic demands on the structure and limit the amount of intrusive retrofit work required. A unique trio of devices was used to isolate the structure, which included three friction sliders, two rubber bearings, and four viscous dampers. The isolation […]

  • Freemark Abbey Winery – Stone Building Renovation – NCSEA Excellence in Structural Engineering Award Winner 2017

    St. Helena | California This historic project consisted of a seismic retrofit and renovation and of approximately 24,000 square feet of total enclosed space including a 14,750 square foot main level historic stone wall winery building with an 8,400 square foot basement. The main floor was altered to level the large retail space, which includes […]

  • Historic Horse Barn Evaluation

    Windsor | California This project involved the review and evaluation of a unique 150 year old historic barn. The barn is octagonal in plan and nearly 120’ across. The interior structure is original heavy timber and clear spans over the center section with an elaborate truss and tension rod system. The cupola stands over 50’ tall […]

  • Phoenix Theatre

    Petaluma | California This historic, two-story building required a seismic retrofit in order to comply with Petaluma’s Ordinance No. 1882, which calls for the improvement of the structural seismic resistance of unreinforced masonry buildings.

  • St. Catherine of Siena New School Wing

    Burlingame | California This two-story building is formed with cast-in-place reinforced concrete and has a flexible wood roof diaphragm. The seismic evaluation was conducted using the ASCE /SEI 31 with a performance objective halfway between “Life Safety” and “Immediate Occupancy,” consistent with the requirements of the Burlingame Municipal Code and the 2007 California Building Code (CBC) […]

  • Bottega Restaurant

    Yountville | California A seismic rehabilitation was designed for this restaurant, located in the historic brick building formerly known as Vintage 1870 and now called V-Marketplace. The restaurant is approximately 4,000 square foot with a 1,300 square foot terrazzo (outdoor patio dining area).

  • Santa Rosa Junior College Burbank Auditorium

    Santa Rosa | California The Burbank Auditorium is one of the older buildings on the SRJC campus. For many decades there had been no structural upgrades to this building. The seismic evaluation was performed to determine the general condition of the building relative to current seismic codes. The scope of work was based on seismic evaluation […]

  • Chateau Montelena

    Calistoga | California Chateau Montelena is a premiere historic winery. The stone building, built circa 1888, was in need of structural upgrades to ensure it would withstand an earthquake. ZFA designed a seismic retrofit scheme to reinforce the second floor framing by adding steel plates on the sides of the 100+yr old wood beams, new pedestals […]