The mortgage must be executed with respect to a project which, in the opinion of the Commissioner, is economically sound, except that this section shall not apply in each of the following instances:

(a) To a mortgage of the character described in § 203.18(d) and with respect to such a mortgage, the Commissioner shall determine that the mortgage is an acceptable risk giving consideration to the need for providing adequate housing for families of low and moderate income, particularly in suburban and outlying areas or small communities.

(b) To a mortgage of the character described in § 203.18 (e).

(c) To a mortgage of the character described in § 203.43a.

(d) To a mortgage in a federally impacted area described in § 203.43e.

(e) To a rehabilitation loan of the character described in § 203.50.