Accessory dwelling units – whether they’re tiny homes for an aging parent or an adult child or a designated hobby space, guest house or tenant space – have become increasingly popular. The Massachusetts Housing Partnership even encourages them through the ADU Incentive Program.
Massachusetts now allows many ADUs of 900 square feet or less by right in single-family residential zoning districts. Even so, the statewide law does not automatically legalize every unit that was built or converted in the past. Before purchasing a property with an existing ADU, a buyer should confirm that the unit complies with applicable state and local requirements.
Check the legalities before you agree to buy
The seller or listing agent may describe the property as having an in-law apartment or rentable second unit, but that description does not establish its legal status. Buyers should ask for building permits, inspection records, certificates of occupancy and any zoning approvals associated with the construction or conversion.
Municipal building and zoning records may reveal whether the work was approved and the ADU may lawfully be occupied. If the seller cannot produce the necessary documentation, the buyer’s attorney may recommend contacting the local building or zoning department. An unpermitted ADU could lead to fines, required alterations or an order prohibiting its use – and all of that will fall on the buyer if the deal goes through.
Another issue of concern is the utilities. An ADU may share electricity, heat, water and other utilities with the main residence or have separate systems and meters. Buyers should understand the arrangement before closing, particularly if they intend to rent the unit. Shared utilities can create practical and legal complications when calculating rent or allocating expenses between the two dwelling spaces. There could be even more complications if the dwellings share a septic system, since the existing system may not be rated to handle that many occupants.
An ADU can add significant value to a Massachusetts home, but the last thing a buyer wants to find out after closing is that the unit cannot be legally occupied or rented. When in doubt, it’s always better to seek experienced legal guidance.