A landlord may not enter into a lease or tenancy at will agreement for a dwelling unit in a multi-unit residential building where the expense of furnishing heat or electricity or any other utility to the common areas or other area not within the unit is the sole responsibility of the tenant in that unit, unless both parties to the lease or tenancy at will agreement have agreed in writing that the tenant will pay for such costs in return for a stated reduction in rent or other specified fair consideration that approximates the actual cost of providing heat or utilities to the common areas. "Common areas" includes, but is not limited to, hallways, stairwells, basements, attics, storage areas, fuel furnaces or water heaters used in common with other tenants. Except as provided in this section, a written or oral waiver of this requirement is against public policy and is void. Any person in violation of this section is liable to the tenant for actual damages or $250, whichever is greater, and reasonable attorneys' fees and costs. In any action brought pursuant to this section, there is a rebuttable presumption that the landlord is aware that the tenant has been furnishing heat or utility service to common areas or other units. If the landlord rebuts this presumption, the landlord is required to comply with this section but is only liable to the tenant for actual damages suffered by the tenant.   [PL 2009, c. 566, §10 (AMD).]