24 C.F.R. § 574.260 – Amendments.

(a) After an application has been selected for funding, any change that will significantly alter the scope, location, service area, or objectives of an activity or the number of eligible persons served must be justified to HUD and approved by HUD. Whenever any other amendment to the application is made, the grantee must provide a copy to HUD.
(b) Each amendment request must contain a description of the revised proposed use of funds. Funds may not be expended for the revised proposed use of funds until:
1. (1) HUD accepts the revised proposed use; and
2. (2) For amendments to acquire, rehabilitate, convert, lease, repair or construct properties to provide housing, an environmental review of the revised proposed use of funds has been completed in accordance with § 574.510.
  (Approved by the Office of Management and Budget under control number 2506-0133)