Upon the acquisition of any land in the name of the Commonwealth, the Department of Property and Supplies¹ shall construct thereon a new institution which shall be known as the “Pennsylvania School for Mental Defectives”. The plans and specifications of the institution shall be subject to the approval of the Department of Welfare, and shall provide for suitable buildings and an adequate water supply system, sewage treatment works, heat and electric power plant or plants, service lines, and other necessary equipment, structures and improvements. The buildings shall be of modern design, plan and substantial, and capable of extension as the needs of the institution may require.