The said Board may, with the consent of the Minister of Education, sell Section 21, Block XV, City of Dunedin, being the site of the present Dunedin Technical School, with the improvements thereon, and on any such sale the Board shall apply the net proceeds thereof in or towards erecting a technical school on the said Sections 21, 22, 33, 34, 35, 36, 37, and 38, Block XIII, City of Dunedin, or on any part thereof.