(2) Under special circumstances, consistent with the definition of a comparable replacement dwelling, modified methods of providing replacement housing of last resort permit consideration of replacement housing based on space and physical characteristics different from those in the displacement dwelling (see appendix A, § 24.404(c)), including upgraded, but smaller replacement housing that is decent, safe, and sanitary and adequate to accommodate individuals or families displaced from marginal or substandard housing with probable functional obsolescence. In no event, however, shall a displaced person be required to move into a dwelling that is not functionally equivalent in accordance with § 24.2(a)(6)(ii) of this part.