This rule recognizes the statutory right of summary process defendants to assert counterclaims. Counterclaims must be asserted with the defendant's answer. A plaintiff against whom a counterclaim is asserted is not required to answer; but an answer to a counterclaim may be filed prior to or at the time of the trial. The court may, of course, in its discretion grant a motion for a continuance in order to grant a party time to prepare a defense to a counterclaim. Because counterclaims are not compulsory, the court retains discretion to sever a counterclaim which cannot appropriately be heard as part of the summary process action. It would, however, appear to be contrary to the law to sever a counterclaim which is being relied upon as a defense under G.L. c. 239, § 8A.
It should be noted that the counterclaim provisions of G.L. c. 239, § 8A apply to premises "rented or leased for dwelling purposes".