The policy of zoning law is to carefully limit the enlargement and extension of nonconforming uses. Arsenault v. Keene, 104 N.H. 356, 359, 187 A.2d 60, 62 (1962); Ackley v. Nashua, 102 N.H. 551, 554, 163 A.2d 6, 9 (1960). The "ultimate purpose of zoning regulations [contemplates that nonconforming uses] should be reduced to conformity as completely and rapidly as possible.

"Where a proposed addition to a nonconforming use greatly increases the intensity of use of premises and would create a substantially greater deviation from the standards contained in an ordinance, the extension of the nonconforming use will not be permitted." 2 E. Yokley, Zoning Law and Practice 16-7, at 239 (3d ed. 1965); see Ackley v. Nashua, 102 N.H. 551, 163 A.2d 6 (1960). Accordingly, the planning board was within both its regulations and its authority in denying petitioner permission to subdivide.

See 2 Rathkopf, The Law of Zoning and Planning 60-3 (1960). It is the general policy of zoning to carefully limit the extension and enlargement of nonconforming uses. 2 Rathkopf, supra ch. 62; New London v. Leskiewicz supra; Arsenault v. Keene, 104 N.H. 356, 187 A.2d 60 (1962); Ackley v. Nashua, 102 N.H. 551, 163 A.2d 6 (1960); Keene v. Blood, 101 N.H. 466, 146 A.2d 262 (1958). In furtherance of this policy we have approved reasonable provisions for the amortization of certain nonconforming uses. Lachapelle v. Goffstown, 107 N.H. 485, 225 A.2d 624 (1967); Annot., 22 A.L.R.3d 1134 (1967).

Such nonconforming uses violate the spirit of zoning, 2 Rathkopf, supra at ch. 62, and they should not be allowed to expand. New London v. Leskiewicz, 110 N.H. 462, 272 A.2d 856 (1970); Arsenault v. Keene, 104 N.H. 356, 187 A.2d 60 (1962); Ackley v. Nashua, 102 N.H. 551, 163 A.2d 6 (1960); Keene v. Blood, 101 N.H. 466, 146 A.2d 262 (1958); 8A McQuillin, Municipal Corporations ss. 25.183, 25.206 (3d ed. 1965 rev. vol.). The nonconforming use ordinarily governed by this law is a static use, a use, such as a store, which might be continued indefinitely without expansion.

The defendant's attack upon the ordinance also centers upon specific provisions requiring the selectmen to "take into consideration the opinions" of all persons taking a position at the hearing, and to give "particular significance to the consent or objections" of abutters and owners of neighboring properties. The ordinance however does not purport to require that a decision by the selectmen shall be "controlled or unduly influenced" by these considerations (Sundlun v. Zoning Board, 50 R.I. 108, 145 A. 451 (1929)), and its provisions are not open to the objections of unconstitutionality, or lack of authority under the zoning statute, which were presented in Robwood Adv. Assoc. v. Nashua, 102 N.H. 215, 153 A.2d 787 (1959), and Ackley v. Nashua, 102 N.H. 551, 163 A.2d 6 (1960). Nor is the ordinance so vague as to furnish no valid standards to guide the selectmen in its administration.

Such an extension would violate the spirit and purpose of zoning legislation and could destroy its effect. DeWitt v. Town of Brattleboro, 128 Vt. 313, 262 A.2d 472, 476 (1970); Ackley v. Nashua, 102 N.H. 551, 163 A.2d 6, 9 (1960). See also La Chapelle v. Goffstown, 107 N.H. 485, 22 A.L.R.3d 1128, 1131 (1967).

"Since the extension or enlargement of a nonconforming use may be more detrimental to zoning than a variance, it has generally been held that a nonconforming use stands in no preferred position. Consequently most decisions that have passed on the point have held that the extension or enlargement of a nonconforming use is to be treated as a variance within the provisions of zoning ordinances." Ackley v. Nashua, 102 N.H. 551, 554, 163 A.2d 6, 9 (1960) (citations omitted); Glidden v. Nottingham, 109 N.H. 134, 135, 244 A.2d 430, 431 (1968). A variance has been defined as authority granted to the owner to use his property in a manner otherwise violative of the zoning regulations.

Accordingly, the enlargement of a non-conforming use by new construction is treated as a variance, rather than an exception to the regulations. Ackley v. Nashua, 102 N.H. 551, 163 A.2d 6, 9; Accord, DeWitt v. Town of Brattleboro Zoning Board of Adjustment, 128 Vt. 313, 262 A.2d 472. Reference to Section XXII, subparagraph 4, in the findings indicates that the court also treated the plaintiff's application as a variance.

Speakman v. North Plainfield, 8 N.J. 250, 84 A.2d 715. In Ackley v. Nashua, 102 N.H. 551, 163 A.2d 6, 9, (1960) Chief Justice Kenison stated that "It is the general policy of zoning to carefully limit the extension and enlargement of nonconforming uses. * * * Since the extension or enlargement of a nonconforming use may be more detrimental to zoning than a variance, it has generally been held that a nonconforming use stands in no preferred position." Construction of an addition to a building on land not previously used for the nonconforming purpose has been held to be a prohibited expansion.

Coolidge v. Planning Board of North Andover, 337 Mass. 648; Colabufalo v. Bd. of Appeal of Newton, 336 Mass. 213. See Ackley v. Nashua, 102 N.H. 551; Jaffrey v. Heffernan, 104 N.H. 249, 252; Note, 44 Minn. L. Rev. 181, 183. The enabling act, under which the ordinance was adopted (RSA 31:60-89) provides for the appointment of a board of adjustment with power to "make special exceptions to the terms of the ordinance."