Opinion by
Judge Rogers,At issue is the validity of an amendment to a zoning ordinance limiting any increase in the size of a building housing a nonconforming use to fifty percent of the size of the building at the time the original ordinance became effective.
The Zoning Hearing Board of Upper Southampton Township denied the application of appellant Schiller-Pfeiffer, Inc. to enlarge by 8,100 square feet the building housing its nonconforming manufacturing, assembly and machine shop operation on the ground that the proposed expansion would violate the above limitation. The Court of Common Pleas of Bucks County affirmed.
Prom a time prior to the enactment of the original Zoning Ordinance of Upper Southampton Township in 1954, Schiller-Pfeiffer has operated a machine shop and plant for the manufacture and assembly of garden tools on a tract of almost six acres of land. To a depth of 450 feet from the public road on which it fronts, the tract is in a C-2 Commercial zoning district; the balance of the tract is in an R-3 Residential zoning district. Part of the building is located in each district and the use is nonconforming in each district. In 1954, when the township’s zoning ordinance was enacted, Schiller-Pfeiffer’s one-story building occupied 36,520 square feet. Prior to October 6, 1962, the date *591of the amendment being attacked, a prior amendment had permitted enlargement of a bnilding housing a nonconforming use to an extent limited only by setback requirements and a requirement that the area of a lot occupied by buildings could not exceed thirty percent of total lot area in a C-2 Commercial District and twenty-five percent in an R-3 Residential District. Pursuant to the first amendment, Schiller-Pfeiffer properly added 14,310 square feet to its building, making the present area of the building 50,830 square feet. On October 6,1962, Section 1203-2 of the zoning ordinance relating to expansion of nonconforming uses was amended to read as follows: “A nonconforming use may be extended throughout the building or structure, or lot in or on which located, and the building in which it is located may be increased in size provided, however, that any such increase in size of the building or of the use will not increase the lot area covered beyond 50 percent of the area covered by the use at the time of the effective date of the original Zoning Ordinance of Upper Southampton Township, Ordinance No. 14, and further provided that any such extension will conform to the height, side, front and rear yard requirements of the Zone in which located.”
Schiller-Pfeiffer was therefore permitted to expand its building, which covered 36,520 square feet at the effective date of the original zoning ordinance, by fifty percent, or an additional 18,260 square feet, making the permitted area 54,780 square feet. The present area being 50,830 square feet, Schiller-Pfeiffer is permitted to expand its building an additional 3,950 square feet but not the 8,100 square feet desired. The present building covers slightly in excess of twenty percent of the entire lot area. Appellee in an Agreed Statement of Facts admitted that the proposed addition is required by natural expansion in appellant’s business which has increased 118 percent since 1962 and admit*592ted that the present production line has become too short for efficient production and cannot be lengthened within the present building unless additional space is provided elsewhere for storage. The Zoning Hearing Board found that the proposed addition would be detrimental to health, safety, morals and the general welfare.
Appellant concedes that a township can impose reasonable restrictions on the expansion of nonconforming uses, but contends that “not only is appellant entitled, as of right, to natural expansion of its nonconforming use, but additional construction must be permitted if required by that natural expansion.” This is a misconception. As the Pennsylvania Supreme Court stated in Hanna v. Board of Adjustment, 408 Pa. 306, 312-13, 183 A. 2d 539, 543 (1962) : “A basic purpose of zoning is to ensure an orderly physical development of the city, borough, township or other community by confining particular uses of property to certain defined areas. With such a purpose nonconforming uses are inconsistent. [citing cases]. . . . Even though zoning ordinances permit the continuance of nonconforming uses, it is the policy of the law to closely restrict such nonconforming uses and to strictly construe provisions in zoning ordinances which provide for the continuance of nonconforming uses. Nonconforming uses, inconsistent with a basic purpose of zoning, represent conditions which should be reduced to conformity as speedily as is compatible with the law and the Constitution.”
In Silver v. Zoning Board of Adjustment, 435 Pa. 99, 102-103, 225 A. 2d 506, 507, 508 (1969), upon which appellant relies, the Supreme Court of Pennsylvania stated: “This right [of natural expansion] is not unlimited, however. The contemplated expansion must not be detrimental to the public health, welfare and safety. We have never questioned the right of a mu*593nicipality to impose reasonable restrictions on the expansion of a nonconforming nse. ... We are well aware that zoning authorities look upon nonconforming issues as the bane of their existence, and we can appreciate their efforts to keep nonconforming uses within bounds. Nevertheless, these authorities cannot arbitrarily abrogate a landowner’s vested right of natural expansion by prohibiting all such growth. The municipality certainly can condition such expansion on certain prerequisites and standards necessary for the preservation of the health, safety and welfare of the community.” The holding in Silver was that a municipality might not completely prohibit the natural expansion of an apartment house by precluding any additional unit whatsoever. The applicant in Silver merely desired to repartition to add additional units without making any addition to the exterior of the building. The ordinance in Silver violated the long-standing rule that a nonconforming use cannot be limited by a zoning ordinance to the prescise magnitude thereof which existed at the date of the ordinance.
Appellant, who asserts that the restriction at bar is unconstitutional as being violative of due process of law as applied to appellant’s premises, has no easy task. As the Pennsylvania Supreme Court has repeatedly held: “One who challenges the constitutionality of a zoning ordinance has no light burden and it is settled that before a zoning ordinance can be declared unconstitutional it must at least be shown that its provisions are clearly arbitrary and unreasonable, having no substantial relation to the public health, safety, morals or general welfare. If the validity of the legislative judgment is fairly debatable, the legislative judgment must be allowed to control.” Glorioso Appeal, 413 Pa. 194, 198, 196 A. 2d 668 (1964), citing Tillage of Euclid v. Ambler Realty Co., 272 U.S. 365, 47 S. Ct. 114, 121 *594(1926); Best v. Zoning Board of Adjustment, 393 Pa. 106, 113, 141 A. 2d 606 (1958); Gratton v. Conte, 364 Pa. 578, 73 A. 2d 381 (1950).
Appellant’s argument that the restriction in the case at bar is unreasonable because it is not based upon the size of the building in relation to the size of the lot overlooks numerous decisions applying similar limitations upon the expansion of nonconforming uses. In Humphreys v. Stuart Realty Corp., 364 Pa. 616, 621, 73 A. 2d 407 (1950), the court declared of a nonconforming use: “permissible enlargement of the use does not warrant the erection of new buildings or structures or any additions to buildings beyond the twenty-five percent allowance hereinbefore referred to.” The court stated that if the storage tanks in question were “structures,” they were prohibited by the ordinance. In Philadelphia Art Alliance v. Philadelphia Zoning Board of Adjustment, 377 Pa. 144, 104 A. 2d 492 (1954), the court applied to expansion of a parking lot an amenda-tory ordinance limiting the extension of nonconforming buildings to twenty-five percent of the area of the building at the time the ordinance was adopted.
Appellant contends that the restriction in the case at bar is unreasonable because “by arbitrary reference to a cut-off date eight years prior to its enactment it limits appellant’s constitutionally protected and vested rights to natural expansion of its nonconforming use.” Appellant complains that the amendment is “retroactive” to the date the original ordinance became effective. In truth, however, reference to such date is entirely reasonable because the relevant date is the date upon which the use became nonconforming. Just as a nonconforming use cannot be limited to the precise magnitude thereof which existed at the date the use became nonconforming, so also is it appropriate to limit the natural expansion of a nonconforming use to a reasonable *595percentage of its size at tbe time the use became nonconforming.1
Appellant deems itself aggrieved because the provisions in effect prior to the 1962 amendment were less restrictive. But a property owner has no vested right to the continued effect and application of a particular district classification or other regulatory provision of a zoning ordinance: Pumo v. Norristown Borough, 404 Pa. 475, 479, 172 A. 2d 828 (1961); Key Realty Co. Zoning Case, 408 Pa. 98, 99, 182 A. 2d 187 (1962). In Walter v. Philadelphia Zoning Board of Adjustment, 437 Pa. 277, 281, 263 A. 2d 123, 126 (1970), the Pennsylvania Supreme Court in holding that an extension of a nonconforming use, which would have been a matter of right under a prior ordinance, was validly rejected under a current ordinance declared: “Appellees’ request for a variance is governed by the provisions of the zoning ordinance as it exists at the time of the application for a variance. It is that ordinance which is the controlling declaration of public policy as to the subject property; that a different policy may have prevailed some years in the past is of no account.”
Order affirmed.
Although appellant points out that retroactive legislation was criticized in Sawdey Liquor License Case, 369 Pa. 19, 85 A. 2d 28 (1951) and Yocum v. Power, 398 Pa. 223, 157 A. 2d 368 (1960), the cases can be distinguished. In Sawdey, the property owner had acquired vested rights by expending substantial sums of money to commence construction of a permitted hotel in reliance upon the existing zoning ordinance which was subsequently amended to prohibit the dispensing of liquor. In Yocum, an amendment prohibiting churches in a district, after a religious organization had obtained a permit to erect a church, was invalid as to that church on the ground of special legislation.