Definition Section

Dwelling Unit, Accessory - a dwelling unit within a single family dwelling that is designed, constructed, altered or converted for the express purpose of enabling a person or persons to reside in the same residential structure but in separate living quarters.

Only one accessory dwelling unit per lot shall be permitted. An accessory dwelling unit may be incorporated within a single family dwelling provided that:

1. The single family dwelling is located on a lot having at least the minimum lot area or frontage required by the Ordinance, or is located on a non-conforming lot which is served by a municipal sewer;
   
   
2. The single family dwelling is located on a lot either served by municipal sewer, or is connected to a septic system with adequate capacity to service the total number of bedrooms within the single family residence and the accessory dwelling unit;
   
   
3. The accessory dwelling unit shall not exceed 800 square feet gross floor area of Habitable Floor Area;
   
   
4. One of the dwelling units shall be occupied by the owner of the property; and
   
   
5. Prior to occupancy of the second dwelling unit, the owner must record an approved “Notice of Limited Occupancy” at the Merrimack County Registry of Deeds.

3.02 Words and Phrases not Defined

Words and phrases not defined in this Article shall have their common meaning unless otherwise stated.

Groundwater: The slowly moving subsurface water present in aquifers and recharge areas.

Habitable Floor Area: The heated, enclosed portions of a building used or designed to be used for human occupancy, work spaces, and related storage areas. To calculate the habitable floor area of a structure, measurements include the areas inside the exterior surface of the outside walls. Basements are included in the calculation of habitable area, where such space complies with life safety codes and where a minimum dimension of six (6) feet eight inches (6'8") exists between floor and ceiling. For partial stories, the space under a sloping roof shall be counted as habitable floor area where a minimum dimension of six (6) feet exists between the floor and ceiling or roof above. Decks, patios, garages, and similar spaces shall not be included in the calculation of habitable floor area.

Height: The vertical distance between the mean elevation of the finished grade surrounding the structure to the highest point of the roof of a building or structure.