A tax paid under this chapter for the construction of a new dwelling unit which is not built is refundable. A refund shall be made upon application of the taxpayer to the director of finance and upon taxpayer’s showing that the construction of the new dwelling unit has not been commenced and the building permit issued therefor has expired, has been cancelled, or has been revoked. Application must be made within one year from the cancellation, expiration or revocation of the building permit. Provided, however, no refund shall be made when a dwelling unit is converted to a use other than as a dwelling unit, or when a dwelling unit is damaged or destroyed. In addition, no refund shall be made for mobile home spaces upon final approval of the construction permit for a mobile home park. (Prior code § 2582)