If streets or utilities are not available at the boundary of a proposed subdivision, and if the Village Planning Commission finds the extensions across undeveloped areas would not be warranted as a special assessment to the intervening properties or as a municipal expense until some future time, the subdivider may be required, prior to approval of the final plat, to obtain necessary easements or right-of-way and construct and pay for such extensions. Such improvements shall be available for connections by subdividers of adjoining land.