Section 5. The department may award to a sponsor of a certified project tax credits available under subsection (q) of section 6 of chapter 62 and section 38BB of chapter 63 not to exceed 10 per cent of the cost of qualified substantial rehabilitation expenditures of the market rate units in the project. The amount and duration of the credit awarded shall be based on the following factors:
(i) the need for residential development and diversity of housing supply in the gateway municipality;
(ii) the extent to which the project will encourage residential development, expansion of diversity of housing supply, support neighborhood stabilization, and promote economic development in the zone; and
(iii) the percentage of market rate units contained in the project.
(b) The department may, limit any incentive or credit available to a project under subsection (q) of section 6 of chapter 62 and section 38BB of chapter 63 to a dollar amount or in any other manner deemed appropriate by the department.