Saving Money and Accelerating Repairs Through Leasing Act or the SMART Leasing Act This bill authorizes the General Services Administration (GSA) to establish a pilot program that allows federal agencies to lease underutilized properties with GSA approval and to use the rent payments to help fund capital projects and facilities maintenance. The GSA may not enter into a lease under the pilot program unless it certifies that the lease will not have a negative impact on its mission or that of the applicable federal agency. The bill provides for a maximum of six leases under the program during each fiscal year, with a term of up to 15 years.