Iowa Code § 565.1: Churches may lease.

Church organizations, occupying real property granted to them by the territory or state, may lease the same for business purposes, and occupy other real property with their church edifices, but all of the income derived from such leased real property shall be devoted to maintaining the religious exercises and ordinance of the church to which the grant was originally made, and to no other purpose; and such churches and their affairs shall remain in the control of boards of trustees regularly chosen in accordance with their charters.