(1) Montana's tax credit for the preservation of historic buildings is to be computed using the federal credit allowed by 26 USC 47, which is a component of the federal general business credit. No other component of the federal general business credit may be used to compute Montana's credit for the preservation of historic buildings.

(2) Qualifying expenditures used to calculate the credit for the preservation of historic buildings must be reduced by amounts used in calculating other Montana tax credits or tax incentives.