The estimates of expenditure requirements transmitted by the Commissioner of Administrative Services to the Secretary of the Office of Policy and Management pursuant to section 4-77 and the appropriations recommended in the budget document transmitted by the Governor to the General Assembly pursuant to section 4-71 shall include an estimate of the amount required by the Department of Administrative Services for the leasing of additional facilities and an estimate of the amount required for the maintenance, including preventive maintenance, of facilities under the supervision, care and control of the department.