The only real way to reduce real estate cost is to reduce space.
Every other cost savings action you take is at best treading water. Anyone can move to a cheaper building, but eventually that building will cost more all over again. Anyone can reduce service levels and find cheaper vendors but your current levels and providers were your choice before, you will eventually go back.
The only real way to reduce your cost is to reduce your space served. Figuring out how to reduce space while helping productivity is the primary focus coat reduction activities should have.
If you are in it for the long haul, there is only one mindset that matters.