If I interpret the 105 CMR, the Sanitary Code, correctly, 3 Red Barn Road, in its present state is in compliance and does not require the installation of additional heating devices.

The code excludes space heaters only as follows:
(B) Portable space heaters, parlor heaters, cabinet heaters, room heaters and any similar heaters having a barometric fed fuel control and its fuel supply tank located less than 42 inches from the center of the burner as well as the type of heating appliance adapted for burning kerosene, range oil or number one fuel oil and any portable wick type space heaters shall not be used and shall not meet the requirements of 105 CMR 410.200. (See M.G.L. c. 148, §§ 5A and 25B.)

The electric space heaters which we have been using are NOT prohibited, nor are propane fed gas heaters such as I had bought and used during construction.

14 years ago, when the building permit was issued, houses to be heated were required to be insulated. Houses not to be heated required no insulation. I assume that a very large proportion of Nantucket "summer homes" are unheated. I interpret 105 CMR to be intended to protect paying tenants against a landlord refusing to keep them warm in winter, but not to impair the privilege of the owner and his family to shiver in their own house.

Even if 105 CMR were applicable to 3 Red Barn Road, which I believe not to be the case, its provisions not be applicable "to the extent the occupant is required to provide the fuel under a written letting agreement." Among family members, such an agreement would be a mere formality.