Due to its unique location and rich history, Nantucket real estate has many nuances. Robust zoning codes, Historic District Commission regulations, and limited infrastructure are just a few of the many pieces in the puzzle of buying and selling on the island. Over recent years, a new challenge has emerged: meeting the infrastructure needs required by an uptick in population while still maintaining our fragile island ecosystem. As a result, an increased focus on septic system regulations and expansion of municipal sewer coverage has occurred. This blog serves as a guide to capacity restrictions with private septic systems.
Those properties that aren’t located in the municipal sewer districts need to have a private septic system serving their property. This enclosed system collects and treats wastewater on-site with characteristics based on the size, zone, and area in which a property is located. Septic systems should be regularly maintained and need to pass an inspection called Title V before the sale of a property. During the marketing and sale process, we refer to the capacity of a septic system based on the bedroom count, but there are also regulations surrounding total room count.
One of the biggest questions we are asked is: what constitutes a bedroom? According to Town code, a bedroom is any habitable space in a structure suitable for living and sleeping that exists in a structure as a room separated from adjacent space by a wall extending from the ceiling to the floor with or without doorways and windows. Further, it must be at least 70 square feet, have a ceiling height of at least seven feet, have electrical service and ventilation, and at least one window. Dining rooms, living rooms, kitchens, halls, bathrooms, closets, unfinished basements, storage and utility space are not considered bedrooms in dwelling units with seven rooms or less. For the purpose of septic system design, single-family dwellings shall be presumed to have at least three bedrooms. Where the total number of rooms for a single-family dwelling is eight or greater, the number of bedrooms presumed shall be calculated by dividing the total number of rooms by two then rounding down to the next lowest whole number. This illustrates the importance of total room count and how it’s not appropriate to use the easy excuse that the room is just an office or a den.
A topic less frequently discussed but of utmost importance is undivided rooms. Anything greater than 50% of the floor area of any single level and greater than 400 square feet in area will be equivalent to two bedrooms for design flow calculation purposes (except for dining rooms, kitchens, halls, bathrooms, and closets). This can be a significant stumbling block for a homeowner wishing to finish a basement without regard to total room count and/or bedroom count. Additionally, finished basements containing at least one full bathroom will be considered as one bedroom.
In the end, it’s always crucial to review the building files and health department (septic) files when getting ready to list your property for sale or if you are a buyer performing due diligence. A comprehensive understanding of these regulations will aid in a smooth transaction, prevent costly delays, and potentially the installation of a new septic system!
If you are interested in learning more about the septic and sewer maze on Nantucket, read my previous blog.