Team Building Tips

I recently took a position with a new company and have three administrative staff who report to me. Some challenges I've been given by my boss, the VP and Division Manager, are to clean up the overall office of clutter and make optimal use of our space as we are running out of room.

My biggest challenge so far is not coming up with solutions to better optimize the space, but getting the three administrative personnel to get on board with me. I get constant resistance from them. I take so much energy trying to convince them of my strategy and the payoff for everyone, only to hear they are complaining to other staff about me. How do I get my group to move toward a team player attitude? HELP!