Unless otherwise indicated, a permit issued by the Building Inspector is required for every sign in, upon or over private property, and for every illuminated sign, regardless of size, including, in all cases, signs located inside the building, which are visible from the adjacent street or from the sidewalks on either side of such street. In determining whether to issue a permit, the Building Inspector shall take into account factors, such as excessive similarity, dissimilarity or inappropriateness of design, color, size or placement of the sign, which would adversely affect or be detrimental to the appearance, character, property values, or development of the properties in the vicinity.