After the hearing provided for by § 151.07, the Council shall sustain, modify or withdraw the notice, depending upon its findings as to whether the provisions of this chapter have been complied with. The Council may also modify a notice so as to authorize a variance from the provisions of this chapter when, because of special conditions, a literal enforcement of the provisions of this chapter will result in practical difficulty or unnecessary hardship; provided, that the spirit of this chapter will be observed, public health and welfare secured and substantial justice done. If the Council sustains or modifies such notice, it shall be deemed to be a final order, and the owner, occupant, lessee, mortgagee, agent or other person having an interest in said building or structure shall comply with all provisions of such order within a reasonable period of time as determined by the Council.
(`89 Code, § 21.080)