When underfloor air is designed into a building from the start of the project, the building can be less expensive to build and less expensive to operate over the life of the building. Underfloor air requires less space per floor, thereby reducing the overall height of the building, which in turn reduces the cost of the building facade. The blowers and air handlers required for underfloor air are much smaller and require less energy, since hot air rises naturally through the space as it comes in contact with people and equipment that warm the air and it rises to the ceiling. Additionally, when buildings are designed to combine modular electrical, modular walls, and access floor, the space within the building can be reconfigured in a few hours, as compared to historical means of demolishing walls and drilling holes in the floor to route electrical and other services. As more companies construct or renovate buildings to meet Leadership in Energy & Environmental Design (LEED) underfloor air and access floor usage will continue to grow. The U.S. Green Building Council (USGBC) states that 40–48 percent of new nonresidential construction is green.