Haw. Rev. Stat. § 444-8: Powers to classify and limit operations.

(a) The contractors license board may adopt rules and regulations necessary to effect the classification of contractors in a manner consistent with established usage and procedure as found in the construction business, and may limit the field and scope of the operations of a licensed contractor to those in which the contractor is classified and qualified to engage, as defined in section 444-7.

(b) A licensee may make application for classification and be classified in more than one classification if the licensee meets the qualifications prescribed by the board for such additional classification or classifications. For qualifying or classifying in additional classifications, the licensee shall pay the appropriate application fee but shall not be required to pay any additional license fee.

(c) This section shall not prohibit a specialty contractor from taking and executing a contract involving the use of two or more crafts or trades, if the performance of the work in the crafts or trades, other than in which the specialty contractor is licensed, is incidental and supplemental to the performance of work in the craft for which the specialty contractor is licensed.