The purposes of this Act are to—
(a) enable a territorial authority, in consultation with its community, to require persons doing developments to facilitate the provision of affordable housing—
(i) for the purpose of meeting a need for it that the authority has identified by doing a housing needs assessment:
(ii) in a manner that takes account of the desirability of the community having a variety of housing sizes, tenures, and costs:
(b) void covenants whose principal purpose is to stop that have, as one of their purposes, stopping the provision of affordable housing or social housing.