(a) to impose as a condition to the approval of a subdivision of land within the municipality that the owner undertakes by agreement with the municipality to provide such land with any work that may be undertaken as a local improvement at the expense of the owner or at such proportion of the expense as the by-law may prescribe; and

(b) to impose as a condition to the issue of a building permit for the erection of any building or structure in the municipality that the owner of the land on which such building or structure is to be erected undertakes by agreement with the municipality to provide such land with any work that may be undertaken as a local improvement at the expense of such owner or at such proportion of the expense as the by-law may prescribe.