In their interpretation and applications, the provisions of this chapter shall be considered as the minimum requirements to promote and to protect public health, safety, comfort, convenience, prosperity and other aspects of the general welfare, and in particular:
A. 
To promote the purposes set forth in the preamble to this chapter and in the statements of legislative intent for the respective districts or groups of districts; and
B. 
To provide a gradual remedy for existing conditions which are detrimental thereto.
Whenever any provisions of this chapter and any other provision of law, whether set forth in this chapter or in any other law, ordinance or resolution of any kind, impose overlapping or contradictory regulations over the use of land or over the use or bulk of buildings or other structures or contain any restrictions covering any of the same subject matter, that provision which is more restrictive or imposes higher standards or requirements shall govern.
In all cases where a building permit has been lawfully issued on the basis of an application showing complete plans for the proposed construction of a new building or other structure, or of an existing building or other structure which requires construction of foundations, and the adoption of this chapter or of any subject amendment thereto would make the completed building or other structure nonconforming or noncomplying, construction may nevertheless be continued in accordance with the building permit and a certificate of occupancy may be issued for such nonconforming or noncomplying building or other structure.