No building shall be erected or used, and no land shall be used, or lot created or divided unless in conformity with the regulations of this Ordinance or other Ordinances of the Town of Portsmouth. All other buildings, and all other uses of land or of buildings, are hereby expressly prohibited, except those already lawfully existing which by the provisions of this Ordinance, become lawfully non-conforming.
This ordinance is designed to address the following purposes. The Town of Portsmouth recognizes these purposes, each with equal priority and numbered for reference purposes only:
1. 
Promote the public health, safety, and general welfare.
2. 
Provide for a range of uses and intensities of use appropriate to the character of the Town, reflecting current and expected future needs, with reasonable consideration of the character of the districts and their peculiar suitability for particular uses.
3. 
Provide for orderly growth and development which recognizes:
a) 
The goals and patterns of land use contained in the comprehensive plan of Portsmouth;
b) 
The natural characteristics of the land, including its suitability for use based on soil characteristics, topography, and susceptibility to surface or groundwater pollution;
c) 
The values and dynamic nature of coastal and freshwater ponds, the shoreline, and freshwater and coastal wetlands;
d) 
The values of unique or valuable natural resources and features;
e) 
The availability and capacity of existing and planned public and/or private services and facilities, as well as the Town's ability to provide them;
f) 
The need to shape and balance urban and rural development, to prevent overcrowding of land; to avoid undue concentration of population; and
g) 
The conservation of the value of buildings.
4. 
Provide for the control, protection, and/or abatement of air, water, groundwater, and noise pollution, and soil erosion and sedimentation;
5. 
Provide for the protection of the natural, historic, cultural, and scenic character of Portsmouth and areas herein;
6. 
Provide for the preservation and promotion of agricultural production, forest, silviculture, aquaculture, timber resources, and open space;
7. 
Provide for and protect the public investment in transportation, water, stormwater management systems, sewage treatment and disposal, solid waste treatment and disposal, schools, roads, recreation, public facilities, open space, and other public requirements;
8. 
Promote a balance of housing choices, for all income levels and groups, to assure the health, safety and welfare of all citizens and their rights to affordable, accessible, safe, and sanitary housing;
9. 
Provide opportunities for the establishment of low and moderate income housing;
10. 
Promote safety from fire, flood, and other natural or man-made disasters;
11. 
Promote a high level of quality in design in the development of private and public facilities;
12. 
Promote implementation of the comprehensive plan of Portsmouth adopted pursuant to Chapter 45-22.2 of the Rhode Island General Laws;
13. 
Provide for coordination of land uses with contiguous municipalities, other municipalities, the state, and other agencies, as appropriate, especially with regard to resources and facilities that extend beyond municipal boundaries or have a direct impact on that municipality;
14. 
Provide for efficient review of development proposals, to clarify and expedite the zoning approval process;
15. 
Provide for procedures for the administration of the zoning ordinance, including, but not limited to, variances, special-use permits, and, where adopted, procedures for modifications;
16. 
Provide for coordination, as necessary, with contiguous communities and the State.
This ordinance shall be interpreted and administered in a manner consistent with Comprehensive Community Plan, dated 1992 as amended. In the instance of uncertainty in the construction or application of any section of this ordinance, the ordinance shall be construed in a manner that will further the implementation of, and not be contrary to, the goals and policies and applicable elements of said Comprehensive Plan.
Nothing contained in this Ordinance shall prevent or be construed to prevent the continuance of the use of any building or improvement for any purpose to which such building or improvement or land is lawfully devoted at the time of enactment of this Ordinance.