The opinion of the court was delivered by
PASHMAN, J.
The issue presented by this appeal is whether a municipality may utilize criteria based upon biological or legal relationships in order to limit the types of groups that may live within its borders. Specifically, we must determine the validity of § 17:3-l(a)(17) of the Plainfield Zoning Ordinance which seeks to preserve the “family” character of the municipality’s neighborhoods by prohibiting more than four unrelated individuals from sharing a single housing unit. For the reasons to be given below, we conclude that although the goal sought to be furthered by that provision is entirely legitimate, the means chosen do not bear a substantial relationship to the effectuation of that goal. Hence, the regulation violates N.J.Const. (1947) Art. I, par. 1 and Art. IV, § 6, par. 2, and cannot stand.
Defendant Dennis Baker is the owner of a house located at 715 Sheridan Avenue, Plainfield. This dwelling is situated in a zone restricted to single family use. On three separate occasions during the fall of 1976 defendant was charged with allowing more than one family to reside in his home in violation of section 17:11-2 of the Plainfield Zoning Ordinance. “Family” is defined in the ordinance as:
One (1) or more persons occupying a dwelling unit as a single non-profit housekeeping unit. More than four (4) persons * * * not related by blood, marriage, or adoption shall not be considered to constitute a family. [City of Plainfield Zoning Ordinance § 17:3-l(a)(17)]
A trial as to all three charges was held in Plainfield Municipal Court. The evidence presented indicated that the home was generally shared by nine individuals: Mr. and Mrs. Baker, their three daughters, Mrs. Conata and her three children. Several other persons also apparently resided within the household for indeterminate periods of time.
The Bakers and Conatas lived together in what defendant termed an “extended family.” The two groups view each other as part of one large family and have no desire to reside in separate homes. Defendant, an ordained minister of the Presbyterian Church, testified that the living arrangement arose out of the individuals’ religious beliefs and resultant desire to go through life as “brothers and sisters.” The Bakers and Conatas ate together, shared common areas and held communal prayer sessions. Each occupant contributed a fixed amount per week to defray household expenses.
Defendant was found guilty of all three charges and fines were imposed. After a trial de novo in the Union County Court—based upon the Municipal Court transcript, see R. 3:23-8(a)—defendant was again found in violation of the ordinance. The County Court judge concluded that defendant’s religious beliefs regarding his lifestyle were sincere and that the household resembled a traditional extended family, thus constituting a “single non-profit housekeeping unit” within the meaning of the zoning ordinance. Nevertheless, he found both that the living arrangement of the Bakers and Conatas violated the numerical restriction of § 17:3-l(a)(17) and that the provision was a valid exercise of the municipality’s police powers. Accordingly, he imposed the same penalties as had the Municipal Court. He ordered, however, that the fines for the first and third violations be suspended.
Defendant filed a notice of appeal to the Appellate Division. State v. Baker, 158 N.J.Super. 536 (App.Div.1978). The appellate judges concluded that “the Plainfield ordinance * * * ‘so narrowly delimits the persons who may occupy a single family dwelling as to prohibit numerous potential occupants who pose no threat to the style of family living sought to be preserved[.]’ ” Id. at 541 (quoting from Berger v. State, 71 N.J. 206, 224 (1976)). Consequently, they held the ordinance invalid insofar as it classified permissible uses according to occupants’ biological or legal relationships. The judges also ruled, however, that the “single non-profit housekeeping unit” criterion used in the ordinance was valid. After concluding that the County Court’s finding that the Baker household constituted such a unit “could reasonably have been reached on sufficient credible evidence present in the record, considering the proofs as a whole * * 158 N.J.Super. at 540, they reversed defendant’s convictions and vacated the fines.
We granted the State’s petition for certification. 77 N.J. 508 (1978). The Public Advocate was permitted to appear as amicus curiae. We now affirm.
I
A municipality’s zoning power, although broad, is not without limits. In order to be valid, a zoning regulation must both represent a reasonable exercise of the police power and bear a real and substantial relation to a legitimate municipal goal. Moreover, the regulation may “not exceed the public need or substantially affect uses which do not partake of the offensive character of those which cause the problem sought to be ameliorated.” Kirsch Holding Co. v. Borough of Manasquan, 59 N.J. 241, 251 (1971). See, e. g., Pascack Ass’n, Ltd. v. Mayor & Coun. of Washington Tp., 74 N.J. 470, 483 (1977); Berger v. State, 71 N.J. 206, 223-224 (1976); J.D. Construction Corp. v. Board of Adj. of Freehold Tp., 119 N.J.Super. 140, 145 (Law Div.1972). Under this test the numerical limitations of § 17:3-l(a)(17) must fall.
We have no quarrel with the legitimacy of Plainfield’s goal. Local governments are free to designate certain areas as exclusively residential and may act to preserve a family style of living. See Berger v. State, supra, 71 N.J. at 223; Collins v. Board of Adj. of Margate City, 3 N.J. 200, 208 (1949); Village of Belle Terre v. Boraas, 416 U.S. 1, 94 S.Ct. 1536, 39 L.Ed.2d 797 (1974). A municipality is validly concerned with maintaining the stability and permanence generally associated with single family occupancy and preventing uses resembling boarding houses or other institutional living arrangements. See Berger v. State, supra, 71 N.J. at 225. Moreover, a municipality has a strong interest in regulating the intensity of land use so as to minimize congestion and overcrowding. As we stated in Berger, a municipality may endeavor in every legitimate way to “secure and maintain ‘the blessings of quiet seclusion’ and to make available to its inhabitants the refreshment of repose and the tranquillity of solitude.” 71 N.J. at 223.
Nevertheless, the power to attain these goals is not without limits. A municipality may not, for example, zone so as to exclude from its borders the poor or other unwanted minorities. See, e. g., Oakwood at Madison, Inc. v. Township of Madison, 72 N.J. 481 (1977); So. Burlington Cty. NAACP v. Tp. of Mt. Laurel, 67 N.J. 151, cert. den. and app. dism., 423 U.S. 808, 96 S.Ct. 18, 46 L.Ed.2d 28 (1975). Nor may zoning be used as a tool to regulate the internal composition of housekeeping units. Taxpayer’s Ass’n of Weymouth Tp. v. Weymouth Tp., 80 N.J. 6, 33 (1976), cert. den. and app. dism., 430 U.S. 977, 97 S.Ct. 1672, 52 L.Ed.2d 373 (1977). See, e. g., Kirsch Holding Co. v. Borough of Manasquan, supra; City of White Plains v. Ferraioli, 34 N.Y.2d 300, 357 N.Y.S.2d 449, 313 N.E.2d 756 (Ct.App.1974). A municipality must draw a careful balance between preserving family life and prohibiting social diversity.
The fatal flaw in attempting to maintain a stable residential neighborhood through the use of criteria based upon biological or legal relationships is that such classifications operate to prohibit a plethora of uses which pose no threat to the accomplishment of the end sought to be achieved. Moreover, such a classification system legitimizes many uses which defeat that goal. Plainfield’s ordinance, for example, would prohibit a group of five unrelated “widows, widowers, older spinsters or bachelors—or even of judges” from residing in a single unit within the municipality. Kirsch Holding Co. v. Borough of Manasquan, supra, 59 N.J. at 248. On the other hand, a group consisting of 10 distant cousins could so reside without violating the ordinance. Thus the ordinance distinguishes between acceptable and prohibited uses on grounds which may, in many cases, have no rational relationship to the problem sought to be ameliorated.
Regulations based upon biological traits or legal relationships necessarily reflect generalized assumptions about the stability and social desirability of households comprised of unrelated individuals—assumptions which in many cases do not reflect the real world. Justice Schaefer, writing for the Supreme Court of Illinois, has noted that
a group of persons bound together only by their common desire to operate a single housekeeping unit, might be thought to have a transient quality that would affect adversely the stability of the neighborhood, * * * And it might be considered that a group of unrelated persons would be more likely to generate traffic and parking problems than would an equal number of related persons.
But none of these observations reflects a universal truth. Family groups are mobile today, and not all family units are internally stable and well-disciplined. Family groups with two or more cars are not unfamiliar. [City of Des Plaines v. Trottner, 34 Ill.2d 432, 437, 216 N.E.2d 116, 119 (Sup.Ct.1966) (emphasis supplied)]
Accordingly, that court held a municipality without power to adopt a zoning ordinance which would “penetrate so deeply * * into the internal composition of a single housekeeping unit.” Id. at 120.
Nevertheless, despite the inexactitude and overinclusiveness of such regulations, we would be reluctant to condemn them in the absence of less restrictive alternatives. Such options do, however, exist.
The courts of this and other states have often noted that the core concept underlying single family living is not biological or legal relationship but, rather, its character as a single housekeeping unit. Berger v. State, supra, 71 N.J. at 227. See Kirsch Holding Co. v. Borough of Manasquan, supra, 59 N.J. at 250; City of Des Plaines v. Trottner, supra; Boston-Edison Protective Ass’n v. Paulist Fathers, 306 Mich. 253, 10 N.W.2d 847 (Sup.Ct. 1943); City of White Plains v. Ferraioli, 34 N.Y.2d 300, 305-307, 357 N.Y.S.2d 449, 452-454, 313 N.E.2d 756, 758-759 (Ct.App. 1974). As long as a group bears the “generic character of a family unit as a relatively permanent household,” it should be equally as entitled to occupy a single family dwelling as its biologically related neighbors. City of White Plains, supra, 34 N.Y.2d at 306, 357 N.Y.S.2d at 453, 313 N.E.2d at 758; see, e. g., Brady v. Superior Ct., 200 Cal.App.2d 69, 19 Cal.Rptr. 242 (Dist.Ct.App.1962); Oliver v. Zoning Comm’n of Chester, 31 Conn.Sup. 197, 326 A.2d 841 (C.P. Middlesex Cty.1974); Carroll v. City of Miami Beach, 198 So.2d 643 (Fla.Dist.Ct.App.1967); Group House of Port Washington, Inc. v. Board of Zoning, 45 N.Y.2d 266, 408 N.Y.S.2d 377, 380 N.E.2d 207 (Ct.App.1978); Little Neck Comm. Ass’n v. Working Org. for Retarded Children, 52 A.D.2d 90, 383 N.Y.S.2d 364 (App.Div.1976); Missionaries of Our Lady of La Salette v. Village of Whitefish Bay, 267 Wis. 609, 66 N.W.2d 627 (Sup.Ct.1954).
Plainfield has a legitimate interest in preserving a “family” style of living in certain residential neighborhoods. Such a goal may be achieved, perhaps more sensibly, by the single-housekeeping unit requirement, as well as the exclusion of incompatible residential uses such as commercial residences, non-familial institutional uses, boarding homes and other such occupancies without infringing unnecessarily upon the freedom and privacy of unrelated individuals. See Berger v. State, supra; Gabe Collins Realty, Inc. v. City of Margate City, 112 N.J.Super. 341, 350 (App.Div.1970).
In addition to preserving a “family” style of living, the municipality also defends its ordinance as necessary to prevent overcrowding and congestion. The instant regulation, however, is too tenuously related to these goals to justify its impingement upon the internal makeup of the housekeeping entity. The Plainfield Ordinance is both underinclusive and overinclusive. It is overinclusive because it prohibits jingle housekeeping units which may not, in fact, be overcrowded or cause congestion; it is underinclusive because it fails to prohibit certain housekeeping units—composed of related individuals—which do present such problems. Thus, for example, five . unrelated retired gentlemen could not share a large eight bedroom estate situated upon five acres of land, whereas a large extended family including aunts, uncles and cousins, could share a small two bedroom apartment without violating this ordinance.
An appropriate method to prevent overcrowding and congestion was suggested by this Court in Kirsch Holding Co. v. Borough of Manasquan, supra. We there stated that
[w]hen intensity of use, /. e., overcrowding of dwelling units and facilities, [presents a problem] consideration might quite properly be given to zoning or housing code provisions, which would have to be of general application, limiting the number of occupants in reasonable relation to available sleeping and bathroom facilities or requiring a minimum amount of habitable floor area per occupant. [59 N.J. at 254 (emphasis supplied)]
See Sente v. Mayor and Mun. Coun. of Clifton, 66 N.J. 204 (1974). Area or facility-related ordinances not only bear a much greater relation to the problem of overcrowding than do legal or biologically based classifications, they also do not impact upon the composition of the household. They thus constitute a more reasoned manner of protecting the public health.
Other legitimate municipal concerns can be dealt with similarly. Traffic congestion can appropriately be remedied by reasonable, evenhanded limitations upon the number of cars which may be maintained at a given residence. Moreover, area-related occupancy restrictions will, by decreasing density, tend by themselves to reduce traffic problems. Disruptive behavior—which, of course, is not limited to unrelated households—may properly be controlled through the use of the general police power. As we stated in Kirsch v. Borough of Manasquan, supra:
Ordinarily obnoxious personal behavior can best be dealt with officially by vigorous and persistent enforcement of general police power ordinances and criminal statutes * * *. Zoning ordinances are not intended and cannot be expected to cure or prevent most anti-social conduct in dwelling situations. [59 N.J. at 253-254]
Restrictions based upon legal or biological relationships such as Plainfield’s impact only remotely upon such problems and hence cannot withstand judicial scrutiny.
Plainfield, in attempting to justify its regulation, relies upon Village of Belle Terre v. Boraas, 416 U.S. 1, 94 S.Ct. 1536, 39 L.Ed.2d 797 (1974). In that case the United States Supreme Court upheld an ordinance which limited to two the number of unrelated individuals who could reside in a single-family dwelling. Belle Terre has been widely criticized by the commentators and its rationale appears to have been undermined in part by the more recent case of Moore v. City of E. Cleveland, 431 U.S. 494, 97 S.Ct. 1932, 52 L.Ed.2d 531 (1977). In any event, Belle Terre is at most dispositive of any federal constitutional question here involved. We, of course, remain free to interpret our constitution and statutes more stringently. See, e. g., Oakwood at Madison, Inc. v. Tp. of Madison, supra, 72 N.J. at 495 n.3; So. Burlington Cty. NAACP v. Tp. of Mt. Laurel, supra, 67 N.J. at 174-175. See generally Brennan, “State Constitutions and the Protection of Individual Rights,” 90 Harv.L.Rev. 489 (1977). We find the reasoning of Belle Terre to be both unpersuasive and inconsistent with the results reached by this Court in Kirsch Holding Co. v. Borough of Manasquan, supra, and Berger v. State, supra. Hence we do not choose to follow it.
The dissent contends that Kirsch Holding Co., supra, was undermined by Belle Terre. Its conclusion in this regard is unsound. First, the dissent rests upon the premise that the Kirsch holding was in fact based upon federal constitutional grounds. That opinion, however, merely held that substantive due process was offended by the regulation at issue; it did not specify whether the federal or state constitution was being invoked. Inasmuch as our own constitution requires zoning ordinances to comport with due process, see Mt. Laurel, supra, there is no reason to believe that Kirsch was not predicated upon both state and federal constitutional grounds. Further, Berger v. State, supra, which is clearly incompatible with Belle Terre, was decided after Belle Terre was handed down. Moreover, Berger specifically endorsed the Kirsch reasoning, thereby indicating that it was only its federal aspect which was undermined by Belle Terre; its state constitutional holding remains unimpaired. In any event, the Kirsch analysis remains logically sound regardless of Belle Terre, and we today reaffirm our adherence to that position.
Finally, Plainfield asserts that its ordinance complies with this Court’s opinion in Berger v. State, supra. In that case we stated, in dictum, that a municipality could validly “restrict single family dwellings to a reasonable number of persons who constitute a bona fide single housekeeping unit.” 71 N.J. at 225. However, we there were dealing with an institutional use in a familial setting and spoke of “persons” rather than unrelated individuals. In light of today’s discussion, we conclude that the use of the word “reasonable” was intended to imply space-related limitations. Thus, Berger merely legitimizes space-related restrictions of general application and, as such, is wholly consistent with our opinion today. See Township of Washington v. Central Bergen Comm. Health Center, Inc., 156 N.J.Super. 388, 415 (Law Div.1978); Holy Name Hospital v. Montroy, 153 N.J. Super. 181 (Law Div.1977).
Accordingly, we hold that zoning regulations which attempt to limit residency based upon the number of unrelated individuals present in a single non-profit housekeeping unit cannot pass constitutional muster. Although we recognize that we are under a constitutional duty to construe municipal powers liberally, see N.J.Const. (1947), Art. IV, § 7, par. 11, municipali ties cannot enact zoning ordinances which violate due process. See, e. g., Pascack Ass’n Ltd. v. Mayor & Council of Washington Tp., 74 N.J. 470, 483 (1977); Berger v. State, 71 N.J. 206, 223-224 (1976); N.J.Const. (1947), Art. I, par. 1; Art. IV, § 6, par. 2.
II
Having concluded that Plainfield’s numerical requirement is invalid, we must determine whether the Baker household fulfilled the remaining municipal criterion of a “single non-profit housekeeping unit.” We conclude that the Baker-Conata alliance was of sufficient permanence so as to resemble a more traditional extended family. Thus, the County Court judge’s finding that the Baker household constituted a “single non-profit housekeeping unit” within the intendment of § 17:3-l(a)(17) is adequately based on the record.
Conclusion
Today we hold that municipalities may not condition residence upon the number of unrelated persons present within the household. Given the availability of less restrictive alternatives, such regulations are insufficiently related to the perceived social ills which they were intended to ameliorate. Although we do not doubt Plainfield’s good faith, the means it chose to further its legitimate goals were overreaching in their scope and hence cannot be permitted to stand.
For the foregoing reasons, the judgment of the Appellate Division is affirmed.
These examples are not, as our dissenting colleagues contend, intended to suggest the possibility of “invasions by swarms of country cousins.” See post at 124. Rather, they are set forth merely to demonstrate that the distinctions utilized by the ordinance are not closely related to the municipality’s valid concerns. Although some arbitrariness in line-drawing may be countenanced when necessary to aclpeve a legitimate goal, it is not to be tolerated where, as here, more precise methods of reaching the desired end are available. See, e. g., Pascack Ass’n Ltd., supra, 74 N.J. at 483; Berger v. State, supra, 71 N.J. at 223-224; Kirsch Holding Co., supra, 59 N.J. at 251.
The dissent notes that Des Plaines has in fact been superseded by statute. It is cited here, however, not for its result but rather for its reasoning which, in our view, remains as valid today as when it was written. See Kirsch Holding Co., supra, 59 N.J. at 249-250 (citing Des Plaines with approval).
The dissent suggests that today’s opinion will allow multi-family occupancy in single family homes. See post at 115-116. This ignores the fact that municipalities are empowered to restrict residences to groups which actually constitute bona fide single-housekeeping units—the true criterion of single residence dwellings. Berger v. State, supra, 71 N.J. at 227. Municipal officials remain free to define in a reasonable manner what constitutes such a unit. Moreover, space-related occupancy limitations, discussed infra, may be used to preclude the possibility of household groups of “unrestricted” size. Thus, only groups compatible with a residential area will benefit by today’s opinion.
We have, in fact, today reaffirmed the appropriateness of such restrictions as a solution to density-related problems. Home Builders League of So. Jersey, Inc. v. Tp. of Berlin, 81 N.J. 127 (1979).
We note that Plainfield does in fact have a minimum space per occupant requirement, although the zoning officer who testified at trial did not know if the Baker household was in violation thereof.
See, e. g., Williams and Doughty, “Studies in Legal Realism: Mount Laurel, Belle Terre and Berman,” 29 Rutgers L.Rev. 73, 76-82 (1975); Hartman, “Village of Belle Terre v. Boraas: Belle Terre is a Nice Place to Visit—But Only ‘Families’ May Live There,” 8 Urb.L.Ann. 193 (1974); Note, “Village of Belle Terre v. Boraas: ‘A Sanctuary for People,”’ 9 U.S.F.L.Rev. 391 (1974).
See, e. g., “Developments in the Law-Zoning,” 91 Harv.L.Rev. 1427, 1568-1574 (1978); “Moore v. City of East Cleveland, Ohio: The Emergence of the Right of Family Choice in Zoning,” 5 Pepperdine L.Rev. 547 (1978).
As Justice Brennan aptly remarked, “state courts cannot rest when they have afforded their citizens the full protections of the federal Constitution. State Constitutions, too, are a font of individual liberties, their protections often extending beyond those required by the [United States] Supreme Court’s interpretation of federal law.” Id. at 491. Constitutional decisions by federal courts, he declared, should only be considered as “guideposts” in interpreting state constitutional provisions “if they are found to be logically persuasive and well-reasoned, paying due regard to precedent and the policies underlying specific constitutional guarantees * * Id. at 502.
The dissent chooses to characterize this aspect of the Berger opinion as dictum. Actually, it was a fully developed alternative holding.
Article I, par. 1 of our Constitution ensures the natural and unalienable right of individuals to pursue and obtain safety and happiness. Encompassed within its strictures is the requirement of due process upon which today’s analysis is based. In addition, we would be remiss if we did not note that the right of privacy is also included within the protection offered by that provision. See, e. g., State v. Saunders, 75 N.J. 200 (1977). Although this right is not absolute, it may be restricted only when necessary to promote a compelling government interest. Article IV, § 6, par. 2 expressly provides that the power to zone shall be deemed to be within the police power of the State. We have, .however, interpreted that provision as mandating that zoning regulations reasonably promote the welfare of the public as a whole. See So. Burlington Cty. NAACP v. Tp. of Mt. Laurel, supra. These provisions, when read together, require that zoning restrictions be accomplished in the manner which least impacts upon the right of individuals to order their lives as they see fit. For the reasons contained herein, the Plainfield regulation fails this test. Thus, it violates the right of privacy and due process.