Property company Bently Holdings has some very unique requirements for the companies who move into the historic office buildings that it owns. Any tenant building out a space must pursue a LEED (Leadership in Energy & Environmental Design) certification. Bently even provides funding for the tenants to do this. So it's not surprising that the Bently Holdings headquarters at Union Square's 240 Stockton, which has recently been renamed Bently Union Square, are very green. They are also warm, intricate and very beautiful, with exposed steel columns and art deco patterns throughout. The building itself was built just after the 1906 earthquake, and the space combines historical touches with modern upgrades. The offices sit on the 7th and 8th floors of Bently Union Square. Although the feeling is old-world glamorous, the technology behind the look is very modern. Temperature, lighting and air control are all managed by a computer, and the building optimizes itself to use the least amount of energy by adjusting to outside air temperatures. A smart lighting system also adjusts to outdoor light coming in through the big windows. The woodwork in the ceilings is certified as sustainable, as is the rich leather in the seating throughout the offices. Most of the office's reused and refurbished materials were collected within 500 miles of San Francisco. There are personal touches throughout the space, as well. Employees have an ongoing chess game on a board displayed on the entryway hall, and a jeans rule board is a remnant from when the office became more casual a year or two ago.