Weebly Headquarters, San Francisco, CA

Syska Hennessy Group was retained by Huntsman Architectural Group to provide mechanical, electrical and plumbing engineering design services for the new Weebly headquarters—36,000 sf in a historical warehouse located south of Market Street in San Francisco’s trendy South Park neighborhood.

This historical building erected in 1890 was first used as a wine production facility. It was heavily damaged by the 1906 earthquake. We were designing the Weebly space while the building was undergoing seismic retrofit along with the MEP infrastructure upgrades.

We expedited our design to provide directions before pouring the new foundation, thick concrete shear walls and concrete slabs. We had to be creative in the design of underground sanitary waste lines and electrical conduits because the basement architectural design had not yet been completed when the team began pouring the foundation and mat slab. The basement contained a commercial kitchen, bathrooms with showers, laundry room and a server room. Syska coordinated with the landlord and the design-build contractors for other MEP infrastructure upgrades so that they would align with Weebly’s fit-out requirements. These included mechanical equipment location, duct riser location, HVAC zoning, increased outside-air distribution per floor, increased general exhaust-rate per floor to match outside air, and provisions for future exhaust ducts from the basement kitchen.

The mechanical system is all new. A variable refrigerant volume (VRV) system was installed for this building, which allows a maximized ceiling height, flexibility in adding HVAC zones and quiet operation. This system does not require the huge supply-air ductwork associated with conventional rooftop central air-handling systems. VRV is very efficient due to its inverter compressor technology and heat recovery option. It has integrated controls and provides the ability to monitor and report building energy usage on an ongoing basis. A dedicated outside-air system provides the required ventilation for the rooms. Ductwork was sized to reduce pressure drop, meet the acoustical goals of the various spaces, and thus reduce fan energy.

The Weebly design team embraced the character and structure of this building in designing the space and the mechanical system. Brick walls and columns were left exposed instead of furring them. Ceilings of numerous spaces were kept exposed to maximize volume of space and daylighting, and several windows were kept operable.