(a) Mandatory requirements. In addition to contractual provisions otherwise required by the Act or this subpart, any energy savings performance contract shall contain clauses—

(1) Authorizing modification, replacement, or changes of equipment, at no cost to the Federal agency, with the prior approval of the contracting officer who shall consider the expected level of performance after such modification, replacement or change;

(2) Providing for the disposition of title to systems and equipment;

(3) Requiring prior approval by the contracting officer of any financing agreements (including lease-acquisitions) and amendments to such an agreement entered into after contract award for the purpose of financing the acquisition of energy conservation measures;

(4) Providing for an annual energy audit and identifying who shall conduct such an audit, consistent with §436.37 of this subpart; and

(5) Providing for a guarantee of energy cost savings to the Federal agency, and establishing payment schedules reflecting such guarantee.

(b) Third party financing. If there is third party financing, then an energy savings performance contract may contain a clause:

(1) Permitting the financing source to perfect a security interest in the installed energy conservation measures, subject to and subordinate to the rights of the Federal agency; and

(2) Protecting the interests of a Federal agency and a financing source, by authorizing a contracting officer in appropriate circumstances to require a contractor who defaults on an energy savings performance contract or who does not cure the failure to make timely payments, to assign to the financing source, if willing and able, the contractor's rights and responsibilities under an energy savings performance contract;