If the Department of City Planning reports that the proposed large-scale residential development can be expected to create a need for one or more new public facilities in the neighborhood, the City Planning Commission may, in its discretion, recommend that a site for one or more such facilities should be reserved within the site of such proposed large-scale residential development. If the Commission does so recommend, the issuance of a building permit shall be withheld for a period not to exceed three months. In such a case, the requirements of this Section shall be considered to be satisfied:

(a)        if, within a period of less than three months, the developer and the appropriate City officials have agreed on the reservation of such a site or sites, or official proceedings have been initiated to authorize acquisition of such a site or sites, or if necessary to amend the capital budget to include the project as a prerequisite to site acquisition; or

(b)        in any event, at the expiration of the above-mentioned period of three months.