A request for a variance from the provisions of this chapter, the permit conditions or the plan specifications may be approved, conditionally approved or denied by the Director of Public Works. The Director of Public Works may refer any variance request filed in accordance with the provisions of this section to the appeal authority as defined in Section 17.93.140. A request for a variance must state in writing: the provision from which a variance is sought, the proposed substitute provisions, when it would apply, and an analysis of the effects of the variance if granted. In granting a variance, the Director of Public Works shall be guided by the following criteria:
(a) Special circumstances or conditions affecting the property;
(b) The necessity of the variance for the proper design and/or function of a reasonable project for the property; and
(c) Adequate measures will be taken to ensure consistency with the purpose of this chapter.