CoreNet: Office space per worker shrinks to 150 sf. The average amount of space per office worker globally has dropped to 150 square feet or less, from 225 square feet in 2010, according to a recent global survey conducted by CoreNet Global.The average amount of space per office worker globally has dropped to 150 square feet or less, from 225 square feet in 2010, according to a recent global survey conducted by CoreNet Global, a leading association of corporate real estate managers at large companies throughout the world.oreNet Global. The average amount of space per office worker globally has dropped to 150 square feet or less, from 225 square feet in 2010, according to a recent global survey conducted by CoreNet Global, a leading association of corporate real estate managers at large companies throughout the world.