The county board may by resolution levy a tax to provide money which shall be kept in a fund known as the county reserve building and maintenance fund. Money in the fund shall be used solely for the construction, maintenance, and equipping of county buildings that are constructed or maintained by the board. The levy shall not be subject to any limit fixed by any other law or by any board of tax levy or other corresponding body, but shall not exceed 0.02215 percent of estimated market value, less the amount required by chapter 475 to be levied in the year for the payment of the principal of and interest on all bonds issued pursuant to Extra Session Laws 1967, chapter 47, section 1.