Hanover Page Mill, a LEED Platinum and net-zero electric building designed by Form4 Architecture for Hanover Page Mill Associates, is a powerful statement of synthesis between architectural form and energy performance. Located at Stanford Research Park in Palo Alto, CA, this spec office building was designed using affordable and practical building strategies to provide higher occupant comfort standards, while offering market-rate leasing options that make it competitive with traditional buildings.
The design is firmly rooted in a Modernist building tradition that follows a C-shaped layout organized on a disciplined five-foot module; the two-story building rises over an underground 118-space parking garage. Sitting on a corner lot, the building is accessible by pedestrians over a short bridge above a canal, which is laid out on a central axis to land on a grand, south-facing square courtyard. Offset from the primary axis, a main entry portico marks access against the window mullions and construction joints visible along the façades.
Emphasis on responsible harnessing of natural resources was a primary concern of the client. The 86,925-square-foot project includes a high-efficiency VAV HVAC system and LED lighting with automatic daylight harvesting, significantly lowering the building’s energy demand. Additional sustainable features include thermally broken glazing system, continuous stone wool insulation at the rain screen metal panel walls, and continuous spray-foam insulation on the backside of the GFRC (glass fiber reinforced concrete) walls, along with ceiling insulation in the basement garage. For solar responsiveness, each façade was fitted with aluminum-and-glass sunshades ranging from 12 inches to 30 inches deep, that were used in multiple compositions to respond to the specific solar orientation of each side, thus improving occupant comfort. This strategy, in combination with relatively narrow floor plates and high-performance double-pane glazing, provides excellent daylighting and dramatically reduces cooling loads from direct solar gain. With resulting lower energy demands, the photovoltaics on the roof and carports are sufficient to fully power the building, achieving net-zero electric status.
The drought-tolerant landscape embodies a spirit of working in the garden, and uses 55% less potable water than would normally be required for landscape irrigation. The entry drive and parking areas are shaded by a grove of trees that marks a transition to the calm, park-like setting of the building. The entry courtyard is beautifully landscaped, serving as a communal gathering space. The elevated terrace on the north side of the building is buffered from the street by a rich landscape, and provides another, more intimate, outdoor space for employees.
Sustainability: Specific strategies to achieve LEED Platinum and net-zero electric energy status include: • On-Site Photovoltaics: On an annual basis, on-site photovoltaics provide 100% of the building’s electric energy use. This includes the energy used by 15 electric car chargers, which are provided to accommodate tenant adoption of lower-emission electric vehicles. • High-Performance Thermal Envelope: The building envelope comprises an R-25 roof, R-16 walls, and an insulated R-16 floor slab over one level of sub-grade parking. Glazing is double-pane Solarban 70XL (U-value: 0.26; VLT: 64%; SHGC: 0.27). Together, these components create a high-performance thermal envelope that reduces HVAC equipment capacity and run-time. • High-Efficiency HVAC System: Highly efficient packaged rooftop air handling units deliver air to thermally actuated diffusers in the space, utilizing readily available technologies that are optimized to increase effectiveness. The air distribution system is designed for extremely low friction losses, with high-efficiency variable speed central fans, while still providing outside air for ventilation at rates 30% greater than code requires for improved indoor air quality. Heating is generated via hot water condensing boilers and zone heating coils. Cooling is provided via a high turndown variable air volume (VAV) system, with high-efficiency central air handling units (COP: 3.713) delivering conditioned air to thermally actuated VAV diffusers. Each VAV diffuser acts as an independent zone of control, allowing the system to respond closely to changing thermal loads. The entire system is designed to reset fan speed based on thermal demand at the zone level. The air handling units and distribution duct work are designed using low-pressure drop principles, which allow for downsizing of the fan motors and low-energy operation. • Solar Responsivity: The architectural design is highly solar responsive: each façade is fitted with exterior overhangs and fins, sized and oriented based on detailed daylight, thermal comfort, and visual comfort studies. A 412 kW solar array on the building and carport roofs is expected to produce 656,000 kWh of electricity annually. • Efficient Water Use: The building uses 40% less water for toilet flushing, hand washing, and showering over baseline via use of low-flow fixtures. Through drought-tolerant plantings and water-efficient irrigation systems, 55% less potable water is required for landscape irrigation. Additionally, the building is dual plumbed to use recycled water for toilet flushing and irrigation, when it becomes available from the City of Palo Alto.