Wilshire Grand Tower: Sustainable Design for the Tallest Building in the Western United States

Tetra Tech helped create a sustainable design for the 73-story, LEED Gold-certified Wilshire Grand, the tallest building in the western United States.

Downtown Los Angeles’ 73-story Wilshire Grand sits in the footprint of its famous predecessor, the Wilshire Grand Hotel, which hosted some of the 20th Century’s most famous international dignitaries. As the hotel grew dated and in need of renovation, owner Hanjin International decided to use the prime location to develop an iconic entry to the Los Angeles skyline that would showcase sustainable design at a large scale. Project architect AC Martin selected Glumac, A Tetra Tech Company, to provide mechanical, electrical, and plumbing design and energy modeling and analysis services to ensure the building’s design was sustainable. Cosentini, A Tetra Tech Company, collaborated with Glumac to develop design concepts and use the team’s high-rise expertise by providing peer reviews throughout design and construction.  

To reduce water use, Tetra Tech designed several water-saving features, including a stormwater and condensate harvesting system to operate the open air cooling towers used for climate control. Large amounts of water are lost during the cooling process, but by trapping and reusing rainwater and condensation rather than pulling from an outside source, the facility stands to save as much as 550,000 gallons of water per year.

The building also has been designed to minimize energy use. Tetra Tech’s team designed a thermal energy storage system, which functions as a load shedding strategy by recharging a large water tank overnight to reduce the number of chillers needed during the day to lower energy usage. We also included radiant heating and cooling systems to optimize the interior comfort of the ground floor and sky lobbies, which are placed mid-way through the building. Tetra Tech’s lighting and energy experts performed enhanced daylighting analysis and shade studies to determine the best interior lighting strategy and materials for the building envelope. We suggested the use of Viracon glass, which was installed on the building exterior to reject solar heat and allow the radiant systems to function more efficiently. Eight of the hotel floors also feature operable windows that work in conjunction with the HVAC system—notifying the HVAC to shut down automatically if the windows are open—to mitigate energy waste.

Tetra Tech’s lighting experts designed an advanced system that reduces the building’s energy usage by 30 percent. Our team improved energy efficiencies by incorporating a key card system that turns off lights and shuts down non-critical plug loads when the room is unoccupied, as well as advanced lighting controls and light emitting diodes (LED) fixtures.

The Wilshire Grand skyscraper stands as a symbol of downtown Los Angeles’ revitalization and as a showcase for innovative design in high-rise buildings. The project surpassed its original target goal of LEED Silver to achieve LEED Gold certification. Working in collaboration with Hanjin International and AC Martin, Tetra Tech’s designs have led to the Wilshire Grand receiving more than $1 million in energy-saving incentives from the Los Angeles Department of Water and Power and Southern California Gas Company.

Highlights

• Wilshire Grand received LEED Gold certification in October 2017
• Engineering News Record (ENR) recognized the project with its 2017 Specialty Construction Award of Merit
• The project team was named the American Institute of Architects 2017 Building Team of the Year Award
• The Wilshire Grand received the 2018 ENR California Best Project Award in the Residential and Hospital category