It shall be unlawful to use, occupy or permit the use or occupancy of any building, land or premises, or part thereof, thereafter created, erected, altered in its structure, enlarged in its use or changed in its use, tenants, ownership or occupants until a certificate of occupancy (use occupancy and compliance) has been issued therefor, stating that the proposed use of land, building or premises conforms to the requirements of the grading and zoning ordinances and the building and fire codes and is, therefore, suitable and eligible for legal occupancy.