5 . Centrally Managed Water System : A water system that provides water for human consumption through pipes of other constructed conveyances to at least 15 service connections or serves an average of at least 25 people for at least 60 days a year as regulated by 10-144 C . M . R Ch . 231 , Rules relating to Drinking Water . This system may be privately owned .
6 . Comparable Sewer System : Any subsurface wastewater disposal system that discharges over 2,000 gallons of wastewater per day as regulated by 10-144 C . M . R . Ch . 241 , Subsurface Wastewater Disposal Rules .
7 . Density Requirements : The maximum number of dwelling units allowed on a lot , subject to the dimensional requirements .
8 . Designated Growth Area : Any area designated in the Town ’ s Comprehensive Plan as suitable for orderly residential , commercial , or industrial development , or any combination of those types of development , and into which most of the development projected over ten ( 10 ) years is directed . Designated Growth Areas may also be referred to as priority development zones or other terms with similar intent .
9 . Dimensional Requirements : Numerical standards relating to spatial relationships including , but not limited to , setbacks , lot area , shore frontage , road frontage , lot depth , and height .
10 . Dwelling Unit : Any part of a structure which thorough sale or lease is intended for human habitation , including single-family and multi-family housing , condominiums , time share units , and apartments .
11 . Existing Dwelling Units : A residential unit in existence on a lot at the time of submission of a permit application to build additional units on the lot . If a municipality does not have a permitting process , the dwelling unit on the lot must be in existence at the time construction begins for the additional units on a lot .
12 . Housing : Any part of a structure which , through sale of lease , is intended for human habitation , including single-family and multi-family housing , condominiums , time-share units , and apartments . For purposes of this rule , this does not include dormitories , boarding houses or other similar types of housing units . This also does not include transient housing or short-term rentals , unless these are otherwise allowed by local ordinance .
13 . Lot : A single parcel of developed or undeveloped land described in a deed or other legal instrument . 14 . Multi-family Dwelling : A structure containing three ( 3 ) or more dwelling units .
15 . Potable : Safe for drinking as defined by the U . S . Environmental Protection Agency ’ s ( EPA ’ s ) Drinking Water Standards and Health Advisory Tables .
16 . Principal Structure : A building or structure other than one which is used for purposes wholly incidental or accessory to the use of another structure or use on the same lot .
17 . Restrictive Covenant : A provision in a deed or other covenant conveying real property , restricting the use of the land .
18 . Single-family Dwelling Unit : A structure containing one ( 1 ) dwelling unit .