(ii) Functionally equivalent to the displacement dwelling. The term functionally equivalent means that it performs the same function, and provides the same utility. While a comparable replacement dwelling need not possess every feature of the displacement dwelling, the principal features must be present. Generally, functional equivalency is an objective standard, reflecting the range of purposes for which the various physical features of a dwelling may be used. However, in determining whether a replacement dwelling is functionally equivalent to the displacement dwelling, the Agency may consider reasonable trade-offs for specific features when the replacement unit is equal to or better than the displacement dwelling (See appendix A, §24.2(a)(6));