Except as hereinafter specified, no building, structures or premises or part thereof shall hereafter be used, and no building or part thereof or other structure shall be constructed, reconstructed, extended, enlarged, or substantially altered, except in conformity with the regulations herein prescribed for the district in which it is located.

The provisions of this ordinance shall not apply to any existing buildings or structures, nor to the existing use of any building, structure or premises as long they remain unchanged.

Existing non-conforming structure or uses may be extended or altered, provided that such extension, alteration or change of use shall be permitted only upon the grant of a Special Permit by the zoning board of appeals after a public hearing and a finding by the board that such extension, alteration or change of use shall not be substantially more detrimental to the neighborhood than the existing non-conforming use or structure.

No non-conforming use, if once changed to a use permitted in the district in which it is located shall never be changed back to a non-conforming use. No non-conforming use or structure which has been abandoned or not used for a period of two (2) years or more shall be resumed or replaced by any other non-conforming use or structure.

Alteration, reconstruction, extension or structural change to a single, two or three family non-conforming, residential structure shall be permitted provided such change does not increase the non-conforming nature of said structure.

Pre-existing, non-conforming structures or uses may be extended, altered or changed in use, providing that such extensions, alterations or changes of use shall be permitted only upon the grant of a Special Permit by the Zoning Board of Appeals and after a public hearing, a finding by the Board that such extension, alteration or change of use shall not be substantially more detrimental to the neighborhood than the existing non-conforming use or structure.

Except for a one, two or three family dwellings, a non-conforming use damaged or destroyed by fire, flood, earthquake, war, riot, or by an Act of God, or an act of the public enemy to the extent of less than seventy-five (75) percent of its reproduction value at the time of such occurrence shall be reconstructed and used as before such calamity provided that a building permit, where required, is obtained and such work started within three (3) years of the date of such occurrence and the work of restoration of the use is completed within two (2) years of the date of the issuance of the building permit.

With reference to the provisions of section 29, Chapter 93, General Laws, no billboard, sign or other advertising device, subject to the rules and regulations of the Commonwealth of Massachusetts, Outdoor Advertising Board, shall be erected or maintained in any district. This restriction shall not apply to such billboards, signs, or other advertising devices, in existence on January 1, 1985, and for which licenses have been issued by said outdoor advertising board in accordance with the provisions of Chapter 93 and Chapter 93D, General Laws.

Any application for zoning approval for any residential use which provides more than three (3) dwelling units or any other use which produces more than five hundred (500) gallons per day of sewage flow when calculated in accordance with the flow estimates of CMR (Mass. Sewer System Extension and Connection Permit Program) Section 7.15 shall require an impact report to be filed with and approved by the Building Inspector, the Department of City Services and the City Engineer, which shall show the total flow; the size, material and slope of all pipes; the ability of the system to carry the flow; locations of manholes and other appurtenances, and invert elevations.

Any applications for zoning approval for use which produces an impermeable surface of more than thirty (30) percent of the lot area of that use shall require an impact report to be filed with and approved by the Building Inspector, Department of City Services and the City Engineer, which shall show the total surface flow, the means of providing the drainage, the method of disposal and if connected to the municipal storm sewer system, shall show the size, material and slope of all pipes; the ability of the system to carry the flow; locations of manholes and other appurtenances, and invert elevations. The provision shall not apply to any application to residential dwellings, three (3) units or less, in dwelling, apartment and business districts.

Providing the total floor area for any building located in more than one zoning district does not exceed the total of the floor areas for each separate zone, then the building shall not be required to comply with the floor area ratio of the individual zone providing furthermore that the building complies with all other dimensional requirements within each zone in which it is located.

Nothing herein contained shall prevent the strengthening or restoring to a safe condition of any part of a building which shall have been declared unsafe by the Inspector of Buildings of from complying with these lawful requirements.

Any lot, which is to be occupied for residential purpose shall have a frontage of at least twenty (20) feet wide on one or more streets and there shall be not more than one (1) structure of the type permitted for each such lot.

No lot shall hereafter be subdivided so as to reduce the area of any yard, court or open space to less than is required by this Ordinance for the lot involved, but such yard or court may include one-half of the width of an alley, railroad right of way, body of water, or another permanently open space along which it extends.

Construction or operations under a building or special permit shall conform to any subsequent amendment of this ordinance unless the use or construction is commenced within a period of not more than six (6) months after the permit and in cases involving construction, unless such construction is continued through to completion as continuously and expeditiously as reasonable.

Up to three (3) dwelling units shall be prohibited except by the grant of a Special Permit by the Zoning board of Appeals in the Business, Business Limited, Industrial and Industrial Limited Districts.

The City of Everett shall be exempt from the provisions of the Building Zone Ordinance in the exercise of its municipal functions.