Vt. Stat. Ann. tit. 12, § 463

A cross-claim or counterclaim shall not be brought if an independent action upon the same claim would have been barred under the provisions of this chapter at the time of commencement of the plaintiff’s action, except that a counterclaim arising out of the transaction or occurrence that is the subject matter of plaintiff’s claim shall be allowed, to the extent of plaintiff’s demand, at any time.