California Code, Government Code - GOV § 8686.4

(a) Whenever the local agency and the director determine for projects that the general public and state interest will be better served by replacing a damaged or destroyed facility with a facility that will more adequately serve the present and future public needs than would be accomplished merely by repairing or restoring the damaged or destroyed facility, the director shall authorize the replacement, including, in the case of a public building, an increase in the square footage of the building replaced, but the cost of the betterment of the facility, to the extent that it exceeds the cost of repairing or restoring the damaged or destroyed facility, shall be borne and contributed by the local agency, and the excess cost shall be excluded in determining the amount to be allocated by the state.  The state contribution shall not exceed the net cost of restoring each facility on the basis of the design of the facility as it existed immediately prior to the disaster in conformity with current codes, specifications, and standards.

(b) Notwithstanding subdivision (a), when the director determines there are mitigation measures that are cost effective and that substantially reduce the risk of future damage, hardship, loss, or suffering in any area where a state of emergency has been proclaimed by the Governor, the director may authorize the implementation of those measures.