No building or land shall hereafter be used or occupied and no building or part thereof shall be erected, moved or altered unless in conformity with the regulations herein specified for the district in which it is or is proposed to be located.

No building shall hereafter be erected or altered to accommodate or house a greater number of families, seasonally or permanently, to occupy a greater percentage of lot area, or to have narrower or smaller rear yards, front yards, side yards, and inner and outer courts than is specified herein for the district in which such building is or is proposed to be located.

No part of a yard or other open space about any building or use required for the purpose of complying with the provisions of this bylaw shall be included as a part of a yard or other open space similarly required for another building or use.

No lot on which a building is located in any district shall be reduced or changed in size or shape so that the building or lot fails to comply with the lot area, width, frontage, setback or yard provisions of this bylaw. This prohibition shall not apply, however, when a portion of a lot is taken or conveyed for a public purpose.

Not more than one dwelling may be erected on a lot.