Section 21. There shall be within the district court department and the Boston municipal court department a simple, informal and inexpensive procedure, hereinafter called the procedure, for the determination, according to the rules of substantive law, of claims in the nature of contract or tort, other than slander and libel, in which the plaintiff does not claim as debt or damages more than $7,000; provided, however, that a city or town may bring an action under section 35 of chapter 60 for the collection of unpaid taxes on personal property or an action which shall not exceed $15,000; and provided further, that said dollar limitation shall not apply to an action for property damage caused by a motor vehicle, and for a review of judgments upon such claims when justice so requires. The procedure shall not be exclusive, but shall be alternative to the formal procedure for civil actions begun by summons and complaint.

The chief justice for the district court department shall make uniform rules with respect to the procedure applicable to all the courts within said department, and the chief justice for the Boston municipal court department shall make rules for the Boston municipal court department, all such rules being subject to the approval of the supreme judicial court.

Actions under this section and sections twenty-two to twenty-five inclusive, shall be brought, at the option of the plaintiff, in the judicial district where either the plaintiff or the defendant lives or has his usual place of business or employment; provided, however, that actions brought against a landlord or lessor of land or tenements rented for residential purposes, and arising out of such property or rental, may also be brought in the judicial district in which the property is located.

Notwithstanding the foregoing, each court within the district court department shall have civil jurisdiction of such actions commenced in such court which should have been brought in some other court, to the extent that the action may be heard and disposed of by the court in which it was begun, if the venue of said action is waived or, if venue requirements are not waived, the court may, on motion of any party, order the action, with all papers relating thereto, transferred for hearing and disposition to the court in which the action should have been commenced. Said action shall thereupon be entered and prosecuted in such court as if it had originally commenced therein, and all prior proceedings otherwise regularly taken shall thereafter be valid. An action may be commenced under this section if the initial amount of damages claimed is $7,000 or less or is an action by a city or town under said section 35 of said chapter 60 for the collection of unpaid taxes on personal property or an action by a city or town which shall not exceed $15,000 for property damage caused by a motor vehicle regardless of the amount of the claims notwithstanding that the court may award double or treble damages in accordance with the provisions of any general or special law.

Actions brought under sections twenty-one to twenty-five, inclusive, may be heard in the first instance by a clerk-magistrate of the district court department or the Boston municipal court department. For the purpose of hearing such property damage claims caused by a motor vehicle the procedure established shall provide for all such claims to be heard on one evening every other week, and on one Saturday on the alternative week, unless otherwise agreed to by all parties in such actions in accordance with the provisions of section thirty-four O of chapter ninety.

In the hearing and disposition of any claim for money damages within the jurisdiction of such procedure, the Boston municipal and district court departments shall have all equity powers and jurisdiction conferred by sections one, one A and two, and clause (1) of section three of chapter two hundred and fourteen.