It wasn’t enough that the addition to Santa Monica City Hall tiptoe unobtrusively behind the original structure, a 1939 Art Deco landmark located in California. The four-story, 50,000-square-foot expansion also had to operate off the grid—in the heart of a major city.
Six years after a 2014 feasibility study, Los Angeles–based architects Frederick Fisher and Partners and global engineering firm Buro Happold, working on a design-build basis with the local office of Hathaway Dinwiddie, completed the Santa Monica City Services Building, also known as City Hall East. The self-sufficiency of the one-stop municipal service hub makes it a lifeline for the community and an exemplar of resilient design in civic architecture for the nation. The building’s innovations lie in both its systems and its envelope.
As FFP and Buro Happold began design work in 2015, the city of Santa Monica was formulating a water neutrality ordinance, which took effect in 2017. This meant that new structures, including the then-forthcoming addition to city hall, could not use more water than was already used on site unless the building owners paid a fee to offset the cost of water-saving infrastructure elsewhere. Also in 2017, Santa Monica passed a stringent energy ordinance and then, in 2019, an ambitious climate action plan. In anticipation of these changes, the city asked FFP and Buro Happold to design City Hall East to pursue Living Building certification, a rigorous green building standard administered by the nonprofit International Living Future Institute that requires buildings to, among many requirements, be net-zero water and net-zero energy. Projects are eligible for certification when its owners can show 12 consecutive months of performance data meeting the criteria.
Embracing the challenge, the FFP and Buro Happold team worked with city, county, and state authorities to navigate building codes to permit composting toilets and an on-site filtration system that converts rainwater to potable water via a 40,000-gallon cistern. “Water that falls on the building comes out of the drinking fountain,” says FFP managing partner Joseph Coriaty, FAIA. State approval was still pending at the time of publication, but the system appears to be unprecedented among non-residential buildings in California.
To operate self-sufficiently without any fossil fuel–burning devices, City Hall East cannot squander a watt from its 250-kilowatt, 15,000-square-foot photovoltaic array or waste a drop of rainwater that lands on its roof. One key to the project's high efficiency is the design of its operable curtain wall. The building envelope comprises standard insulated glass units, with both automatic and manual sashes, configured with a mix of transparent vision glass and semi-opaque fritted glass that varies level by level and elevation by elevation to minimize peak cooling loads. “The façade is working hard to control heat gain,” says Buro Happold principal Julian Parsley.
To test the visual effect of frits baked onto the low-e coated glass at varying densities, the designers printed the frit patterns at full scale and pasted them on their own office windows first, and then on construction mock-ups. “The daylight coming through is nice and soft as a result of the glass specifications and the narrow proportions of the building,” Coriaty says. User-operated awning windows are installed near desk height; automated windows near the ceiling open for cooling and fresh air. The natural ventilation is particularly important on summer nights, when the outdoor temperature typically drops to about 63 F after hitting daytime highs in the mid-70s F. “The building skin developed into a bit of a machine,” says FFP partner Matthew Kelley, AIA.
Also integrated into the building envelope, hidden in the spandrel area, are packets of phase-change material that slowly absorb and release heat, acting as ancillary thermal mass to buffer temperature changes. The sheets of PCM contain plastic pouches filled with a vegetable oil–based compound that changes from solid to gel when the ambient temperature exceeds a user-specified range. For City Hall East, the compound melts between 75 F and 78 F, Parsley says.
The design team stuffed as many of the sheets as possible not only in the curtain wall spandrel areas, but also into the interior stud-frame walls and above the acoustical ceiling clouds. In total, the building uses approximately 40,000 square feet of PCM sheets. Though admittedly low-tech, “the phase-change material is a great way of cooling the building without using carbon or energy,” says Kathleen Hetrick, senior sustainability engineer at Buro Happold.
Two active HVAC systems supplement the building’s multiple passive technologies. A radiant system embedded in the concrete floor slabs can handle about half the peak expected load. On very hot or cold days, a conventional ducted variable-air-volume system kicks in to keep occupants comfortable.
Outside, City Hall East includes a courtyard where edible and native plants grow beneath a canopy of date palms. This garden and Tongva Park, a larger green space designed by James Corner Field Operations and located in front of the original City Hall, join the FFP and Buro Happold–designed building in expressing the idea that civic functions are inextricable from environmental ones. If other cities learn from Santa Monica’s holistic example, perhaps more public architecture as well as other building types could enter a new and exciting phase of sustainable design.
This article has been updated since first publication to include the role of Hathaway Dinwiddie in the project.