As a result of its renovation, not only did the Integral Group manage to earn the highest LEED-CI Platinum rating ever awarded by the U.S. Green Building Council to a building, but it did so on a budget of $25 per square foot … proof that a green retrofit doesn’t have to be expensive.
The Integral Group’s renovation of its 1930s building in Oakland, CA, was done in part to show that careful planning and sustainable design can lead to energy efficiency and occupant comfort for a reasonable price. The team was able to achieve an overall 37% reduction in energy use and 40% reduction in water use.
Much of the energy savings in this project are due to implementation of a high-efficiency natural gas fired boiler and ventilation air handler. Night-time purging of hot air significantly reduces the need for mechanical air-conditioning in almost all areas.
To better control occupant comfort, each cubicle has its own radiator and thermostatic control valve that can be adjusted as necessary. Occupants also have access to operable windows. Natural ventilation from the windows is supplemented with low-energy personal desktop fans that are found in every cubicle.
Server virtualization also helped with Integral Group’s energy savings. Virtualization eliminated four of the five servers being used, which saved more than 65% of server energy use.
The Integral Group also focused on reducing plug load, achieving a 49% reduction. The organization purchases best-in-class ENERGY STAR computers, monitors, appliances, and other office equipment. Many employees’ desktops were switched out for lower-energy-use laptops. Some occupants are using thin clients as well, which led to an 80% reduction in computer energy use. (A thin client is a low-end computer terminal that provides a graphical user interface to the user while the operating system and software are provided by the server.)
Five-watt LED task lights have contributed to plug load reductions as well, along with plug load strips that incorporate occupancy sensors. When the occupant leaves his or her cubicle, everything plugged into the strip shuts off.
Check out this short video to tour the space. Have you tried any of the methods the Integral Group used? Do you think $25 per square feet is a reasonable budget to work with for a retrofit?