A permit issued shall be construed to be a license to proceed with the work and not as authority to violate, cancel, alter or set aside any of the provisions of the technical codes, nor shall issuance of a permit prevent the building official from thereafter requiring a correction of errors in plans, construction, or violations of this code. Every permit issued shall become invalid unless the work authorized by such permit is commenced within six months after its issuance, or if the work authorized by such permit is suspended or abandoned for a period of six months after the time work is commenced. The permit shall become invalid after three years from the date of its issuance in zoning districts of the city, unless the building or buildings subject to the permit have exteriors and landscaping which are in substantial compliance with the plans and specifications and comply with the provisions of section 34-96, section 34-97, subsections 34-98(3)--(9), and (11), section 34-99, and section 34-122 of the City code of Ordinances. Extensions of time for building permits may be granted only by the city council. Further, any unfinished buildings or structures for which a permit has lapsed or otherwise become invalid, and where the appearance and other conditions of such unfinished building or structure substantially detracts from the appearance of the immediate neighborhood, or reduces the value of property in the immediate neighborhood, or is a nuisance shall be deemed to be a violation of the above referenced code sections, which violation may be enforced by the code enforcement board.