Close all offices except essential personnel the day after Thanksgiving. Many people use this day and its a waste to operate with lights, energy, guards, etc... for a few people.
This idea applies to ALL federal agencies. All federal employees and visitors should pay the market rate for parking at ALL federal owned and leased buildings. This will encourage the use of public transportation, telecommuting, and carpooling. It will reduce traffic congestion and cost of road maintenance. It will reduce the federal budget deficit.