Temporary structures or uses. The Board of Appeals may authorize a temporary and revocable permit for not more than two years for uses or structures that do not conform with the regulations of this chapter for the district in which they are located, provided that the following findings are made:
(1) That such use is of a temporary nature and does not involve the erection or enlargement of any permanent structure.
(2) In case of a renewal of such permit, that all conditions and safeguards previously required have been complied with.