Case Study 2

CASE STUDY 2: 260 Townsend, San Francisco

In 2002, the building contractor Swinerton began efforts to retrofit its own newly purchased San Francisco headquarters to serve as a model energy-efficient retrofit project. Swinerton’s office space at 260 Townsend, San Francisco was originally built in 1984 with 67,000 ft2 of office space, 28,000 ft2 of covered parking and 19,000 ft2 of terraces.

Retrofit improvements undertaken at 260 Townsend included the installation of a new digitally controlled building management system (BMS), efficiency upgrades to lighting and equipment commissioning.

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Efficiency achievements

The retrofit project allowed 260 Townsend to exceed California’s Title 24-2001 commercial building energy standard by 12%, with a final building energy use intensity of 16 kWh/square foot/year. As a result of the efficiency improvements, 260 Townsend earned a gold level certification through Leadership in Energy and Environmental Design for Existing Buildings (LEED EB).

As a result of the retrofit project, Swinerton’s headquarters achieved:
• LEED-EB Gold certification
• 50% reduction in energy bills
-1,072,000 kWh saved annually
-2,700 BTU saved annually
• 30% drop in occupant water use
• 60% drop in irrigation water use

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Building Management System

Prior to the Swinerton retrofit, the building management system (BMS) at 260 Townsend was nearly 20 years old. Although still functioning, the system was far from optimal. Swinerton replaced the system with an Emcor BMS with direct digital controls. The new BMS enabled remote monitoring of temperature, CO2, humidity and energy demand, and allowed Swinerton to automatically adjust HVAC and lighting systems for optimal performance and efficiency. The BMS system also collects data on systems performance and energy consumption and helps to identify
equipment malfunctions, which enables optimally efficient operation and increased equipment lifetime. The energy costs savings achieved by the BMS at 260 Townsend allowed for a payback of installation costs in just 1.7 years.

Swinerton’s BMS is designed to sub-meter each floor and track energy usage data on a floor-level basis, enabling the company to pass energy costs on to specific groups based on usage. This detailed metering helps teams to recognize their role in the energy consumption of the facility, and has helped create an atmosphere of individual accountability and commitment to energy savings at Swinerton.

Lighting retrofit

Swinerton also implemented lighting retrofits throughout its office space and covered parking structure. Daylighting was increased by reducing the number of private offices around the perimeter of the building, allowing natural light to penetrate further into interior workspaces. Exit signs were also upgraded to more efficient models. The energy benefits from these lighting projects are displayed in Table F.3.

In the parking garage, lights were changed from T12 fluorescent fixtures to metal halide fixtures, reducing total demand by 7,950 watts. The metal halide fixtures were outfitted with motion sensors to minimize their operation time. This upgrade is also described in Table F.3.

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Transportation

Swinerton’s headquarters at 260 Townsend has access to a variety of public transportation options. It is located next to six bus stops, the Municipal Railway (“Muni”) N-Judah Train and the Southbay commuter rail CalTrain. Alternative transportation is further encouraged by reserved access to parking for vanpools, carpool, hybrid and electric vehicles. Additionally, there is a secure bicycle storage and shower facility
available to employees as well as two bicycles and one electric vehicle available for use around the city. All of these efforts reduce individual driving into the workplace and around the city. Moreover, these efforts may have value-added health benefits such as reduced stress and improved fitness.

Water efficiency

Indoor and outdoor efforts contributed to the water savings achieved by Swinerton. Outdoors, native vegetation was planted along with high-efficiency irrigation equipment. Indoors, all showerheads and faucets were retrofitted with low-flow aerators. Additionally, toilets that utilized five gallons per flush were replaced with toilets that use only 1.5 gallons per flush, a reduction of 70% of water use per flush. These steps combined to reduce Swinerton’s water consumption 30% per occupant and a full 60% reduction in irrigation water use.

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