California Code, Financial Code - FIN § 1320

(a) Such as may be necessary or convenient for the use, operation or housing of its head office and branch offices, or for the storage of records or other personal property, or for office space for use by its officers or employees, or which may be reasonably necessary for future expansion of its business, or which is otherwise reasonably related to the conduct of its business. Real property used by a bank as its banking premises may include in addition to the space required for the transaction of its business other space which may be let as a source of income.

(b) Such as may be conveyed to it in satisfaction in whole or in part of debts previously contracted in the course of its business.

(c) Such as it may purchase or acquire at foreclosure sales under mortgages or deeds of trust held by it, or under judgments or decrees in its favor.

(d) Such as it may purchase or otherwise acquire when necessary to minimize or prevent the loss or destruction of any lien or interest therein.

(e) Such as it may purchase or otherwise acquire pursuant to Section 1322.

A bank or trust company may sell, lease, or encumber real property or any interest therein owned by it, or, with the written approval of the commissioner, exchange the same for other real property.