Rules for proving a building's value and improvement costs

(a) All structures proposed to be substantially improved must be brought into compliance with this chapter. For the purpose of determining substantial improvement, the applicant shall provide the market value of a structure and the cost of the proposed improvements to the structure from the following sources: (1) Itemized estimates made by an independent professional construction estimator; (2) Appraisals prepared by an independent licensed appraiser, including appraisals of market value; and (3) Calculations based on square foot cost factors published in building cost estimating guides recognized by the building construction industry, and signed and stamped by an independent licensed engineer or architect. (b) The director may require additional or revised documentation should the estimated market value or cost of improvements appear to be inconsistent with the specific characteristics of the building.