(a) The board of trustees shall maintain the offices of the retirement system in Austin and may, but is not required to:
(1) cause the system to own real estate on or in which those offices are located;
(2) contract for and construct a building or buildings to house those offices, along with related structures such as parking garages;
(3) lease office space from others;
(4) lease space in its offices, or in a building that previously has been its offices, to other persons or entities;
(5) maintain, modify, or construct improvements on any real estate, whether for the retirement system or a tenant; or
(6) sell real estate that previously has been the retirement system's offices.
(b) The board shall keep the books and records of the retirement system in those offices.