Buildings and works for the construction of a single dwelling and variation of the Restrictive Covenant contained in Transfer No. A094810 for Lot 13 on Plan of Subdivision 041939 by deleting the words “hereafter excavate carry away or remove or permit to be excavated carried away or removed any earth clay stone gravel or sand from the said lots hereby transferred except for the purpose of excavation for the foundations of any building to be erected thereon on or", and "and such building shall be in accordance with plans and specifications to be approved in writing by or behalf of the transferrers"