The opinion of the Court was delivered by HALL, J.

This case attacks the system of land use regulation by defendant Township of Mount Laurel on the ground that low and moderate income families are thereby unlawfully excluded from the municipality. The trial court so found, 119 N.J. Super. 164 (Law Div. 1972), and declared the township zoning ordinance totally invalid. Its judgment went on, in line with the requests for affirmative relief, to order the municipality to make studies of the housing needs of low and moderate income persons presently or formerly residing in the community in substandard housing, as well as those in such income classifications presently employed in the township and living elsewhere or reasonably expected to be employed therein in the future, and to present a plan of affirmative public action designed "to enable and encourage the satisfaction of the indicated needs." Jurisdiction was retained for judicial consideration and approval of such a plan and for the entry of a final order requiring its implementation.

The township appealed to the Appellate Division and those plaintiffs, not present or former residents, cross-appealed on the basis that the judgment should have directed that the prescribed plan take into account as well a fair share of the regional housing needs of low and moderate income families without limitation to those having past, present or prospective connection with the township. The appeals were certified on our own motion before argument in the Division. R. 2:12-1.

The implications of the issue presented are indeed broad and far-reaching, extending much beyond these particular plaintiffs and the boundaries of this particular municipality.

There is not the slightest doubt that New Jersey has been, and continues to be, faced with a desperate need for housing, especially of decent living accommodations economically suitable for low and moderate income families. The situation was characterized as a "crisis" and fully explored and documented by Governor Cahill in two special messages to the Legislature — A Blueprint for Housing in New Jersey (1970) and New Horizons in Housing (1972).

Plaintiffs represent the minority group poor (black and Hispanic) seeking such quarters. But they are not the only category of persons barred from so many municipalities by reason of restrictive land use regulations. We have reference to young and elderly couples, single persons and large, growing families not in the poverty class, but who still cannot afford the only kinds of housing realistically permitted in most places — relatively high-priced, single-family detached dwellings on sizeable lots and, in some municipalities, expensive apartments. We will, therefore, consider the case from the wider viewpoint that the effect of Mount Laurel's land use regulation has been to prevent various categories of persons from living in the township because of the limited extent of their income and resources. In this connection, we accept the representation of the municipality's counsel at oral argument that the regulatory scheme was not adopted with any desire or intent to exclude prospective residents on the obviously illegal basis of race, origin or believed social incompatibility.

As already intimated, the issue here is not confined to Mount Laurel. The same question arises with respect to any number of other municipalities of sizeable land area outside the central cities and older built-up suburbs of our North and South Jersey metropolitan areas (and surrounding some of the smaller cities outside those areas as well) which, like Mount Laurel, have substantially shed rural characteristics and have undergone great population increase since World War II, or are now in the process of doing so, but still are not completely developed and remain in the path of inevitable future residential, commercial and industrial demand and growth. Most such municipalities, with but relatively insignificant variation in details, present generally comparable physical situations, courses of municipal policies, practices, enactments and results and human, governmental and legal problems arising therefrom. It is in the context of communities now of this type or which become so in the future, rather than with central cities or older built-up suburbs or areas still rural and likely to continue to be for some time yet, that we deal with the question raised.

Extensive oral and documentary evidence was introduced at the trial, largely informational, dealing with the development of Mount Laurel, including the nature and effect of municipal regulation, the details of the region of which it is a part and the recent history thereof, and some of the basics of housing, special reference being directed to that for low and moderate income families. The record has been supplemented by figures, maps, studies and literature furnished or referred to by counsel and the amici, so that the court has a clear picture of land use regulation and its effects in the developing municipalities of the state.

This evidence was not contradicted by the township, except in a few unimportant details. Its candid position is that, conceding its land use regulation was intended to result and has resulted in economic discrimination and exclusion of substantial segments of the area population, its policies and practices are in the best present and future fiscal interest of the municipality and its inhabitants and are legally permissible and justified. It further asserts that the trial court was without power to direct the affirmative relief it did.

I

The Facts

Mount Laurel is a flat, sprawling township, 22 square miles, or about 14,000 acres, in area, on the west central edge of Burlngton County. It is roughly triangular in shape, with its base, approximately eight miles long, extending in a northeasterly-southwesterly direction roughly parallel with and a few miles east of the Delaware River. Part of its southerly side abuts Cherry Hill in Camden County. That section of the township is about seven miles from the boundary line of the city of Camden and not more than 10 miles from the Benjamin Franklin Bridge crossing the river to Philadelphia.

In 1950, the township had a population of 2817, only about 600 more people than it had in 1940. It was then, as it had been for decades, primarily a rural agricultural area with no sizeable settlements or commercial or industrial enterprises. The populace generally lived in individual houses scattered along country roads. There were several pockets of poverty, with deteriorating or dilapidated housing (apparently 300 or so units of which remain today in equally poor condition). After 1950, as in so many other municipalities similarly situated, residential development and some commerce and industry began to come in. By 1960 the population had almost doubled to 5249 and by 1970 had more than doubled again to 11,221. These new residents were, of course, "outsiders" from the nearby central cities and older suburbs or from more distant places drawn here by reason of employment in the region. The township is now definitely a part of the outer ring of the South Jersey metropolitan area, which area we define as those portions of Camden, Burlington and Gloucester Counties within a semicircle having a radius of 20 miles or so from the heart of Camden city. And 65% of the township is still vacant land or in agricultural use.

The growth of the township has been spurred by the construction or improvement of main highways through or near it. The New Jersey Turnpike, and now route I-295, a freeway paralleling the turnpike, traverse the municipality near its base, with the main Camden-Philadelphia turnpike interchange at the corner nearest Camden. State route 73 runs at right angles to the turnpike at the interchange and route 38 slices through the northeasterly section. Routes 70 and U.S. 130 are not far away. This highway network gives the township a most strategic location from the standpoint of transport of goods and people by truck and private car. There is no other means of transportation.

The location and nature of development has been, as usual, controlled by the local zoning enactments. The general ordinance presently in force, which was declared invalid by the trial court, was adopted in 1964. We understand that earlier enactments provided, however, basically the same scheme but were less restrictive as to residential development. The growth pattern dictated by the ordinance is typical.

Under the present ordinance, 29.2% of all the land in the township, or 4,121 acres, is zoned for industry. This amounts to 2,800 more acres than were so zoned by the 1954 ordinance. The industrial districts comprise most of the land on both sides of the turnpike and routes I-295, 73 and 38. Only industry meeting specified performance standards is permitted. The effect is to limit the use substantially to light manufacturing, research, distribution of goods, offices and the like. Some non-industrial uses, such as agriculture, farm dwellings, motels, a harness racetrack, and certain retail sales and service establishments, are permitted in this zone. At the time of trial no more than 100 acres, mostly in the southwesterly corner along route 73 adjacent to the turnpike and I-295 interchanges, were actually occupied by industrial uses. They had been constructed in recent years, mostly in several industrial parks, and involved tax ratables of about 16 million dollars. The rest of the land so zoned has remained undeveloped. If it were fully utilized, the testimony was that about 43,500 industrial jobs would be created, but it appeared clear that, as happens in the case of so many municipalities, much more land has been so zoned than the reasonable potential for industrial movement or expansion warrants. At the same time, however, the land cannot be used for residential development under the general ordinance.

The amount of land zoned for retail business use under the general ordinance is relatively small — 169 acres, or 1.2% of the total. Some of it is near the turnpike interchange; most of the rest is allocated to a handful of neighborhood commercial districts. While the greater part of the land so zoned appears to be in use, there is no major shopping center or concentrated retail commercial area — "downtown" — in the township.

The balance of the land area, almost 10,000 acres, has been developed until recently in the conventional form of major subdivisions. The general ordinance provides for four residential zones, designated R-1, R-1D, R-2 and R-3. All permit only single-family, detached dwellings, one house per lot — the usual form of grid development. Attached town-houses, apartments (except on farms for agricultural workers) and mobile homes are not allowed anywhere in the township under the general ordinance. This dwelling development, resulting in the previously mentioned quadrupling of the population, has been largely confined to the R-1 and R-2 districts in two sections — the northeasterly and southwesterly corners adjacent to the turnpike and other major highways. The result has been quite intensive development of these sections, but at a low density. The dwellings are substantial; the average value in 1971 was $32,500 and is undoubtedly much higher today.

The general ordinance requirements, while not as restrictive as those in many similar municipalities, nonetheless realistically allow only homes within the financial reach of persons of at least middle income. The R-1 zone requires a minimum lot area of 9,375 square feet, minimum lot width of 75 feet at the building line, and a minimum dwelling floor area of 1,100 square feet if a one-story building and 1,300 square feet if one and one-half stories or higher. Originally this zone comprised about 2,500 acres. Most of the subdivisions have been constructed within it so that only a few hundred acres remain (the testimony was at variance as to the exact amount). The R-2 zone, comprising a single district of 141 acres in the northeasterly corner, has been completely developed. While it only required a minimum floor area of 900 square feet for a one-story dwelling, the minimum lot size was 11,000 square feet; otherwise the requisites were the same as in the R-1 zone.

The general ordinance places the remainder of the township, outside of the industrial and commercial zones and the R-1D district (to be mentioned shortly), in the R-3 zone. This zone comprises over 7,000 acres — slightly more than half of the total municipal area — practically all of which is located in the central part of the township extending southeasterly to the apex of the triangle. The testimony was that about 4,600 acres of it then remained available for housing development. Ordinance requirements are substantially higher, however, in that the minimum lot size is increased to about one-half acre (20,000 square feet). (We understand that sewer and water utilities have not generally been installed, but, of course, they can be.) Lot width at the building line must be 100 feet. Minimum dwelling floor area is as in the R-1 zone. Presently this section is primarily in agricultural use; it contains as well most of the municipality's substandard housing.

The R-1D district was created by ordinance amendment in 1968. The area is composed of a piece of what was formerly R-3 land in the western part of that zone. The district is a so-called "cluster" zone. See generally 2 Williams, American Planning Law: Land Use and the Police Power, §§ 47.01-47.05 (1974). That writer defines the concept as follows:

* * * Under the usual cluster-zoning provisions, both the size and the width of individual residential lots in a large (or medium-sized) development may be reduced, provided (usually) that the overall density of the entire tract remains constant — provided, that is, that an area equivalent to the total of the areas thus "saved" from each individual lot is pooled and retained as common open space. The most obvious advantages include a better use of many sites, and relief from the monotony of continuous development. § 47.01, pp. 212-213.

Here this concept is implemented by reduction of the minimum lot area from 20,000 square feet required in the R-3 zone to 10,000 square feet (12,000 square feet for corner lots) but with the proviso that one-family houses — the single permitted dwelling use — "shall not be erected in excess of an allowable development density of 2.25 dwelling units per gross acre." The minimum lot width at the building line must be 80 feet and the minimum dwelling floor area is the same as in the R-3 zone. The amendment further provides that the developer must set aside and dedicate to the municipality a minimum of 15% and a maximum of 25% of the total acreage for such public uses as may be required by the Planning Board, including "but not limited to school sites, parks, playgrounds, recreation areas, public buildings, public utilities." Some dwelling development has taken place in this district, the exact extent of which is not disclosed by the record. It is apparent that the dwellings are comparable in character and value to those in the other residential zones. The testimony was that 486 acres remained available in the district.

A variation from conventional development has recently occurred in some parts of Mount Laurel, as in a number of other similar municipalities, by use of the land use regulation device known as "planned unit development" (PUD). This scheme differs from the traditional in that the type, density and placement of land uses and buildings, instead of being detailed and confined to specified districts by local legislation in advance, is determined by contract, or "deal," as to each development between the developer and the municipal administrative authority, under broad guidelines laid down by state enabling legislation and an implementing local ordinance. The stress is on regulation of density and permitted mixture of uses within the same area, including various kinds of living accommodations with or without commercial and industrial enterprises. The idea may be basically thought of as the creation of "new towns" in virgin territory, full-blown or in miniature, although most frequently the concept has been limited in practice, as in Mount Laurel, to residential developments of various sizes having some variety of housing and perhaps some retail establishments to serve the inhabitants. See generally, 2 Williams, supra, §§ 48.01 to 48.12; cf. Cheney v. Village 2 at New Hope, Inc., 429 Pa. 626, 241 A.2d 81, 82-83 (1968).

New Jersey passed such enabling legislation in 1967 ( L. 1967, c. 61, amended c. 286, N.J.S.A. 40:55-54, et seq.), which closely follows a model act found in 114 U. Pa. L. Rev. 140 (1965), and Mount Laurel adopted the implementing enactment as a supplement to its general zoning ordinance in December of that year. While the ordinance was repealed early in 1971, the township governing body in the interim had approved four PUD projects, which were specifically saved from extinction by the repealer.

These projects, three in the southwesterly sector and one in the northeasterly sector, are very substantial and involve at least 10,000 sale and rental housing units of various types to be erected over a period of years. Their bounds were created by agreement rather than legislative specification on the zoning map, invading industrial, R-1, R-1D, R-3 and even flood plain zones. If completed as planned, they will in themselves ultimately quadruple the 1970 township population, but still leave a good part of the township undeveloped. (The record does not indicate how far development in each of the projects has progressed.) While multi-family housing in the form of rental garden, medium rise and high rise apartments and attached townhouses is for the first time provided for, as well as single-family detached dwellings for sale, it is not designed to accommodate and is beyond the financial reach of low and moderate income families, especially those with young children. The aim is quite the contrary; as with the single-family homes in the older conventional subdivisions, only persons of medium and upper income are sought as residents.

A few details will furnish sufficient documentation. Each of the resolutions of tentative approval of the projects contains a similar fact finding to the effect that the development will attract a highly educated and trained population base to support the nearby industrial parks in the township as well as the business and commercial facilities. The approvals also sharply limit the number of apartments having more than one bedroom. Further, they require that the developer must provide in its leases that no school-age children shall be permitted to occupy any one-bedroom apartment and that no more than two such children shall reside in any two-bedroom unit. The developer is also required, prior to the issuance of the first building permit, to record a covenant, running with all land on which multi-family housing is to be constructed, providing that in the event more than .3 school children per multi-family unit shall attend the township school system in any one year, the developer will pay the cost of tuition and other school expenses of all such excess numbers of children. In addition, low density, required amenities, such as central air conditioning, and specified developer contributions help to push rents and sales prices to high levels. These contributions include fire apparatus, ambulances, fire houses, and very large sums of money for educational facilities, a cultural center and the township library.

Still another restrictive land use regulation was adopted by the township through a supplement to the general zoning ordinance enacted in September 1972 creating a new zone, R-4, Planned Adult Retirement Community (PARC). The supplementary enactment designated a sizeable area as the zone — perhaps 200 acres — carved out of the R-1D and R-3 districts in the southwesterly sector. The enactment recited a critical shortage of adequate housing in the township suitable "for the needs and desires of senior citizens and certain other adults over the age of 52." The permission was essentially for single ownership development of the zone for multi-family housing (townhouses and apartments), thereafter to be either rented or sold as cooperatives or condominiums. The extensive development requirements detailed in the ordinance make it apparent that the scheme was not designed for, and would be beyond the means of, low and moderate income retirees. The highly restricted nature of the zone is found in the requirement that all permanent residents must be at least 52 years of age (except a spouse, immediate family member other than a child, live-in domestic, companion or nurse). Children are limited to a maximum of one, over age 18, residing with a parent and there may be no more than three permanent residents in any one dwelling unit.

All this affirmative action for the benefit of certain segments of the population is in sharp contrast to the lack of action, and indeed hostility, with respect to affording any opportunity for decent housing for the township's own poor living in substandard accommodations, found largely in the section known as Springville (R-3 zone). The 1969 Master Plan Report recognized it and recommended positive action. The continuous official reaction has been rather a negative policy of waiting for dilapidated premises to be vacated and then forbidding further occupancy. An earlier non-governmental effort to improve conditions had been effectively thwarted. In 1968 a private non-profit association sought to build subsidized, multi-family housing in the Springville section with funds to be granted by a higher level governmental agency. Advance municipal approval of the project was required. The Township Committee responded with a purportedly approving resolution, which found a need for "moderate" income housing in the area, but went on to specify that such housing must be constructed subject to all zoning, planning, building and other applicable ordinances and codes. This meant single-family detached dwellings on 20,000 square foot lots. (Fear was also expressed that such housing would attract low income families from outside the township.) Needless to say, such requirements killed realistic housing for this group of low and moderate income families.

The record thoroughly substantiates the findings of the trial court that over the years Mount Laurel "has acted affirmatively to control development and to attract a selective type of growth" ( 119 N.J. Super. at 168) and that "through its zoning ordinances has exhibited economic discrimination in that the poor have been deprived of adequate housing and the opportunity to secure the construction of subsidized housing, and has used federal, state, county and local finances and resources solely for the betterment of middle and upper-income persons." ( 119 N.J. Super. at 178).

There cannot be the slightest doubt that the reason for this course of conduct has been to keep down local taxes on property (Mount Laurel is not a high tax municipality) and that the policy was carried out without regard for nonfiscal considerations with respect to people, either within or without its boundaries. This conclusion is demonstrated not only by what was done and what happened, as we have related, but also by innumerable direct statements of municipal officials at public meetings over the years which are found in the exhibits. The trial court referred to a number of them. 119 N.J. Super. at 169-170. No official testified to the contrary.

This policy of land use regulation for a fiscal end derives from New Jersey's tax structure, which has imposed on local real estate most of the cost of municipal and county government and of the primary and secondary education of the municipality's children. The latter expense is much the largest, so, basically, the fewer the school children, the lower the tax rate. Sizeable industrial and commercial ratables are eagerly sought and homes and the lots on which they are situate are required to be large enough, through minimum lot sizes and minimum floor areas, to have substantial value in order to produce greater tax revenues to meet school costs. Large families who cannot afford to buy large houses and must live in cheaper rental accommodations are definitely not wanted, so we find drastic bedroom restrictions for, or complete prohibition of, multi-family or other feasible housing for those of lesser income.

This pattern of land use regulation has been adopted for the same purpose in developing municipality after developing municipality. Almost every one acts solely in its own selfish and parochial interest and in effect builds a wall around itself to keep out those people or entities not adding favorably to the tax base, despite the location of the municipality or the demand for varied kinds of housing. There has been no effective intermunicipal or area planning or land use regulation. All of this is amply demonstrated by the evidence in this case as to Camden, Burlington and Gloucester counties. As to the similar situation generally in the state, see New Jersey Department of Community Affairs, Division of State and Regional Planning, Land Use Regulation, The Residential Land Supply (April 1972) (a study assembling and examining the nature and extent of municipal zoning practices in 16 counties as affecting residential land available for low and moderate income housing) and Williams and Norman, Exclusionary Land Use Controls: The Case of North-Eastern New Jersey, 22 Syracuse L. Rev. 475, 486-487 (1971). One incongruous result is the picture of developing municipalities rendering it impossible for lower paid employees of industries they have eagerly sought and welcomed with open arms (and, in Mount Laurel's case, even some of its own lower paid municipal employees) to live in the community where they work.

The other end of the spectrum should also be mentioned because it shows the source of some of the demand for cheaper housing than the developing municipalities have permitted. Core cities were originally the location of most commerce and industry. Many of those facilities furnished employment for the unskilled and semi-skilled. These employees lived relatively near their work, so sections of cities always have housed the majority of people of low and moderate income, generally in old and deteriorating housing. Despite the municipally confined tax structure, commercial and industrial ratables generally used to supply enough revenue to provide and maintain municipal services equal or superior to those furnished in most suburban and rural areas.

The situation has become exactly the opposite since the end of World War II. Much industry and retail business, and even the professions, have left the cities. Camden is a typical example. The testimonial and documentary evidence in this case as to what has happened to that city is depressing indeed. For various reasons, it lost thousands of jobs between 1950 and 1970, including more than half of its manufacturing jobs (a reduction from 43,267 to 20,671, while all jobs in the entire area labor market increased from 94,507 to 197,037). A large segment of retail business faded away with the erection of large suburban shopping centers. The economically better situated city residents helped fill up the miles of sprawling new housing developments, not fully served by public transit. In a society which came to depend more and more on expensive individual motor vehicle transportation for all purposes, low income employees very frequently could not afford to reach outlying places of suitable employment and they certainly could not afford the permissible housing near such locations. These people have great difficulty in obtaining work and have been forced to remain in housing which is overcrowded, and has become more and more substandard and less and less tax productive. There has been a consequent critical erosion of the city tax base and inability to provide the amount and quality of those governmental services — education, health, police, fire, housing and the like — so necessary to the very existence of safe and decent city life. This category of city dwellers desperately needs much better housing and living conditions than is available to them now, both in a rehabilitated city and in outlying municipalities. They make up, along with the other classes of persons earlier mentioned who also cannot afford the only generally permitted housing in the developing municipalities, the acknowledged great demand for low and moderate income housing.

II

The Legal Issue

The legal question before us, as earlier indicated, is whether a developing municipality like Mount Laurel may validly, by a system of land use regulation, make it physically and economically impossible to provide low and moderate income housing in the municipality for the various categories of persons who need and want it and thereby, as Mount Laurel has, exclude such people from living within its confines because of the limited extent of their income and resources. Necessarily implicated are the broader questions of the right of such municipalities to limit the kinds of available housing and of any obligation to make possible a variety and choice of types of living accommodations.

We conclude that every such municipality must, by its land use regulations, presumptively make realistically possible an appropriate variety and choice of housing. More specifically, presumptively it cannot foreclose the opportunity of the classes of people mentioned for low and moderate income housing and in its regulations must affirmatively afford that opportunity, at least to the extent of the municipality's fair share of the present and prospective regional need therefor. These obligations must be met unless the particular municipality can sustain the heavy burden of demonstrating peculiar circumstances which dictate that it should not be required so to do.

We reach this conclusion under state law and so do not find it necessary to consider federal constitutional grounds urged by plaintiffs. We begin with some fundamental principles as applied to the scene before us.

Land use regulation is encompassed within the state's police power. Our constitutions have expressly so provided since an amendment in 1927. That amendment, now Art. IV, sec. VI, par. 2 of the 1947 Constitution, authorized legislative delegation of the power to municipalities (other than counties), but reserved the legislative right to repeal or alter the delegation (which we take it means repeal or alteration in whole or in part). The legislative delegation of the zoning power followed in 1928, by adoption of the standard zoning enabling act, now found, with subsequent amendments, in N.J.S.A. 40:55-30 to 51.

It is elementary theory that all police power enactments, no matter at what level of government, must conform to the basic state constitutional requirements of substantive due process and equal protection of the laws. These are inherent in Art. I, par. 1 of our Constitution, the requirements of which may be more demanding than those of the federal Constitution. Robinson v. Cahill, 62 N.J. 473 , 482, 490-492 (1973); Washington National Insurance Co. v. Board of Review, 1 N.J. 545 , 553-554 (1949). It is required that, affirmatively, a zoning regulation, like any police power enactment, must promote public health, safety, morals or the general welfare. (The last term seems broad enough to encompass the others). Conversely, a zoning enactment which is contrary to the general welfare is invalid. See generally, e.g., Roselle v. Wright, 21 N.J. 400 , 409-410 (1956); Katobimar Realty Co. v. Webster, 20 N.J. 114 , 122-123 (1955); Schmidt v. Board of Adjustment of Newwark, 9 N.J. 405 , 413-419 (1952); Collins v. Board of Adjustment of Margate City, 3 N.J. 200 , 206 (1949). Indeed these considerations are specifically set forth in the zoning enabling act as among the various purposes of zoning for which regulations must be designed. N.J.S.A. 40:55-32. Their inclusion therein really adds little; the same requirement would exist even if they were omitted. If a zoning regulation violates the enabling act in this respect, it is also theoretically invalid under the state constitution. We say "theoretically" because, as a matter of policy, we do not treat the validity of most land use ordinance provisions as involving matters of constitutional dimension; that classification is confined to major questions of fundamental import. Cf. Tidewater Oil Co. v. Mayor and Council of the Borough of Carteret, 44 N.J. 338 , 343 (1965). We consider the basic importance of housing and local regulations restricting its availability to substantial segments of the population to fall within the latter category.

The demarcation between the valid and the invalid in the field of land use regulation is difficult to determine, not always clear and subject to change. This was recognized almost fifty years ago in the basic case of Village of Euclid v. Ambler Realty Co., 272 U.S. 365, 47 S.Ct. 114, 71 L.Ed. 303 (1926):

The ordinance now under review and all similar laws and regulations must find their justification in some aspect of the police power, asserted for the public welfare. The line which in this field separates the legitimate from the illegitimate assumption of power is not capable of precise delimitation. It varies with circumstances and conditions. ( 272 U.S. at 387, 47 S.Ct. at 118, 71 L.Ed. at 310).

This court has also said as much and has plainly warned, even in cases decided some years ago sanctioning a broad measure of restrictive municipal decisions, of the inevitability of change in judicial approach and view as mandated by change in the world around us. Lionshead Lake, Inc. v. Township of Wayne, 10 N.J. 165, 172-173 (1952), appeal dismissed 344 U.S. 919, 73 S.Ct. 386, 97 L.Ed. 708 (1953) (approving requirement of minimum floor area for dwellings, the same in all residential districts); Fischer v. Township of Bedminster, 11 N.J. 194 , 205 (1952) (sanctioning minimum lot area of five acres in a then rural municipality); Pierro v. Baxendale, 20 N.J. 17 , 29 (1955) (holding valid an ordinance permitting boarding and rooming houses, but not hotels and motels, in residential districts); Vickers v. Township Committee of Gloucester Township, 37 N.J. 232, 250 (1962), cert. den. 371 U.S. 233, 83 S.Ct. 326, 9 L.Ed.2d 495 (1963) (sustaining ordinance provisions prohibiting mobile home parks throughout the township). The warning is perhaps best put in Pierro:

We are aware of the extensive academic discussion following the decisions in the Lionshead and Bedminster cases, supra, and the suggestion that the very broad principles which they embody may intensify dangers of economic segregation which even the more traditional modes of zoning entail * * *. In the light of existing population and land conditions within our State these [municipal zoning] powers may fairly be exercised without in anywise endangering the needs or reasonable expectations of any segments of our people. If and when conditions change, alterations in zoning restrictions and pertinent legislative and judicial attitudes need not be long delayed. ( 20 N.J. at 29).

The warning implicates the matter of whose general welfare must be served or not violated in the field of land use regulation. Frequently the decisions in this state, including those just cited, have spoken only in terms of the interest of the enacting municipality, so that it has been thought, at least in some quarters, that such was the only welfare requiring consideration. It is, of course, true that many cases have dealt only with regulations having little, if any, outside impact where the local decision is ordinarily entitled to prevail. However, it is fundamental and not to be forgotten that the zoning power is a police power of the state and the local authority is acting only as a delegate of that power and is restricted in the same manner as is the state. So, when regulation does have a substantial external impact, the welfare of the state's citizens beyond the borders of the particular municipality cannot be disregarded and must be recognized and served.

This essential was distinctly pointed out in Euclid, where Mr. Justice Sutherland specifically referred to "* * * the possibility of cases where the general public interest would so far outweigh the interest of the municipality that the municipality would not be allowed to stand in the way." ( 272 U.S. at 390, 47 S.Ct. at 119, 71 L.Ed. at 311). Chief Justice Vanderbilt said essentially the same thing, in a different factual context, in the early leading case of Duffcon Concrete Products, Inc. v. Borough of Cresskill, 1 N.J. 509 (1949), when he spoke of the necessity of regional considerations in zoning and added this:

* * * The effective development of a region should not and cannot be made to depend upon the adventitious location of municipal boundaries, often prescribed decades or even centuries ago, and based in many instances on considerations of geography, of commerce, or of politics that are no longer significant with respect to zoning. The direction of growth of residential areas on the one hand and of industrial concentration on the other refuses to be governed by such artificial lines. Changes in methods of transportation as well as in living conditions have served only to accentuate the unreality in dealing with zoning problems on the basis of the territorial limits of a municipality. ( 1 N.J. at 513).

See, to the same general effect, Borough of Cresskill v. Borough of Dumont, 15 N.J. 238 , 247-249 (1954).

In recent years this court has once again stressed this nonlocal approach to the meaning of "general welfare" in cases involving zoning as to facilities of broad public benefit as distinct from purely parochial interest. See Roman Catholic Diocese of Newark v. Ho-Ho-Kus Borough, 42 N.J. 556 , 566 (1964), id., 47 N.J. 211 (1966). In this case we pointed out local action with respect to private educational projects largely benefitting those residing outside the borough must be exercised "with due concern for values which transcend municipal lines." ( 47 N.J. at 218). Likewise in Kunzler v. Hoffman, 48 N.J. 277 (1966), a case unsuccessfully attacking a use variance granted a private hospital to serve the emotionally disturbed in a wide area of the state, we rejected the contention that local zoning authorities are limited to a consideration of only those benefits to the general welfare which would be received by residents of the municipality, pointing out that "general welfare" in the context there involved "comprehends the benefits not merely within municipal boundaries but also those to the regions of the State relevant to the public interest to be served." 48 N.J. at 288.

This brings us to the relation of housing to the concept of general welfare just discussed and the result in terms of land use regulation which that relationship mandates. There cannot be the slightest doubt that shelter, along with food, are the most basic human needs. See Robinson v. Cahill, supra ( 62 N.J. at 483). "The question of whether a citizenry has adequate and sufficient housing is certainly one of the prime considerations in assessing the general health and welfare of that body." New Jersey Mortgage Finance Agency v. McCrane, 56 N.J. 414 , 420 (1970). Cf. DeSimone v. Greater Englewood Housing Corp. No. 1, 56 N.J. 428, 442 (1970). The same thought is implicit in the legislative findings of an extreme, long-time need in this state for decent low and moderate income housing, set forth in the numerous statutes providing for various agencies and methods at both state and local levels designed to aid in alleviation of the need. See, e.g., Mortgage Finance Agency Law, N.J.S.A. 17:1B-5 ( L. 1970, c. 38); Department of Community Affairs Demonstration Grant Law, N.J.S.A. 52:27D-61 ( L. 1967, c. 82); Local Housing Authorities Law, N.J.S.A. 55:14A-2 ( L. 1938, c. 19); Housing Co-operation Law, N.J.S.A. 55:14B-2 ( L. 1938, c. 20); Redevelopment Companies Law, N.J.S.A. 55:14D-2 ( L. 1944, c. 169); State Housing Law, N.J.S.A. 55:14H-2 ( L. 1949, c. 303); Senior Citizens Nonprofit Rental Housing Tax Law, N.J.S.A. 55:14I-2 ( L. 1965, c. 92); Housing Finance Agency Law, N.J.S.A. 55:14J-2 ( L. 1967, c. 81); Limited-Dividend Nonprofit Housing Corporations or Associations Law, N.J.S.A. 55:16-2 (as amended L. 1967, c. 112).

It is plain beyond dispute that proper provision for adequate housing of all categories of people is certainly an absolute essential in promotion of the general welfare required in all local land use regulation. Further the universal and constant need for such housing is so important and of such broad public interest that the general welfare which developing municipalities like Mount Laurel must consider extends beyond their boundaries and cannot be parochially confined to the claimed good of the particular municipality. It has to follow that, broadly speaking, the presumptive obligation arises for each such municipality affirmatively to plan and provide, by its land use regulations, the reasonable opportunity for an appropriate variety and choice of housing, including, of course, low and moderate cost housing, to meet the needs, desires and resources of all categories of people who may desire to live within its boundaries. Negatively, it may not adopt regulations or policies which thwart or preclude that opportunity.

It is also entirely clear, as we pointed out earlier, that most developing municipalities, including Mount Laurel, have not met their affirmative or negative obligations, primarily for local fiscal reasons. Governor Cahill summed it up in his 1970 special legislative message, A Blueprint for Housing in New Jersey, supra, at 10-11:

We have reached a point in the State where the zoning criteria in many municipalities is two-fold; dwelling units of all kinds must be curtailed; industrial development must be encouraged. This is a far cry from the original concept of municipal zoning and planning * * *. The fundamental objective of (the) constitutional amendment and the implementing Municipal Zoning Enabling Act was local control of zoning and planning for the purpose of effecting the public good * * *. The original concept of local planning and zoning never contemplated prohibition in lieu of regulation nor the welfare of the few in place of the general welfare.

The exclusionary details are fully set forth in Land Use Regulation, The Residential Land Supply, previously referred to.

In sum, we are satisfied beyond any doubt that, by reason of the basic importance of appropriate housing and the long-standing pressing need for it, especially in the low and moderate cost category, and of the exclusionary zoning practices of so many municipalities, conditions have changed, and consistent with the warning in Pierro, supra, judicial attitudes must be altered from that espoused in that and other cases cited earlier, to require, as we have just said, a broader view of the general welfare and the presumptive obligation on the part of developing municipalities at least to afford the opportunity by land use regulations for appropriate housing for all.

We have spoken of this obligation of such municipalities as "presumptive." The term has two aspects, procedural and substantive. Procedurally, we think the basic importance of appropriate housing for all dictates that, when it is shown that a developing municipality in its land use regulations has not made realistically possible a variety and choice of housing, including adequate provision to afford the opportunity for low and moderate income housing or has expressly prescribed requirements or restrictions which preclude or substantially hinder it, a facial showing of violation of substantive due process or equal protection under the state constitution has been made out and the burden, and it is a heavy one, shifts to the municipality to establish a valid basis for its action or non-action. Robinson v. Cahill, supra, 62 N.J. at 491-492, and cases cited therein. The substantive aspect of "presumptive" relates to the specifics, on the one hand, of what municipal land use regulation provisions, or the absence thereof, will evidence invalidity and shift the burden of proof and, on the other hand, of what bases and considerations will carry the municipality's burden and sustain what it has done or failed to do. Both kinds of specifics may well vary between municipalities according to peculiar circumstances.

We turn to application of these principles in appraisal of Mount Laurel's zoning ordinance, useful as well, we think, as guidelines for future application in other municipalities.

The township's general zoning ordinance (including the cluster zone provision) permits, as we have said, only one type of housing — single-family detached dwellings. This means that all other types — multi-family including garden apartments and other kinds housing more than one family, town (row) houses, mobile home parks — are prohibited. Concededly, low and moderate income housing has been intentionally excluded. While a large percentage of the population living outside of cities prefers a one-family house on its own sizeable lot, a substantial proportion do not for various reasons. Moreover, single-family dwellings are the most expensive type of quarters and a great number of families cannot afford them. Certainly they are not pecuniarily feasible for low and moderate income families, most young people and many elderly and retired persons, except for some of moderate income by the use of low cost construction on small lots.

As previously indicated, Mount Laurel has allowed some multi-family housing by agreement in planned unit developments, but only for the relatively affluent and of no benefit to low and moderate income families. And even here, the contractual agreements between municipality and developer sharply limit the number of apartments having more than one bedroom. While the township's PUD ordinance has been repealed, we mention the subject of bedroom restriction because, assuming the overall validity of the PUD technique (see footnote (5), supra), the measure could be reenacted and the subject is of importance generally. The design of such limitations is obviously to restrict the number of families in the municipality having school age children and thereby keep down local education costs. Such restrictions are so clearly contrary to the general welfare as not to require further discussion. Cf. Molino v. Mayor and Council of Borough of Glassboro, 116 N.J. Super. 195 (Law Div. 1971).

Mount Laurel's zoning ordinance is also so restrictive in its minimum lot area, lot frontage and building size requirements, earlier detailed, as to preclude single-family housing for even moderate income families. Required lot area of at least 9,375 square feet in one remaining regular residential zone and 20,000 square feet (almost half an acre) in the other, with required frontage of 75 and 100 feet, respectively, cannot be called small lots and amounts to low density zoning, very definitely increasing the cost of purchasing and improving land and so affecting the cost of housing. As to building size, the township's general requirements of a minimum dwelling floor area of 1,100 square feet for all one-story houses and 1,300 square feet for all of one and one-half stories or higher is without regard to required minimum lot size or frontage or the number of occupants (see Sente v. Mayor and Municipal Council of City of Clifton, 66 N.J. 204 , 208-209 (1974)). In most aspects these requirements are greater even than those approved in Lionshead Lake, Inc. v. Township of Wayne, supra, 10 N.J. 165 , almost 24 years ago and before population decentralization, outer suburban development and exclusionary zoning had attained today's condition. See also Williams and Wacks, Segregation of Residential Areas Along Economic Lines: Lionshead Lake Revisited, 1969 Wis. L. Rev. 827. Again it is evident these requirements increase the size and so the cost of housing. The conclusion is irresistible that Mount Laurel permits only such middle and upper income housing as it believes will have sufficient taxable value to come close to paying its own governmental way.

Akin to large lot, single-family zoning restricting the population is the zoning of very large amounts of land for industrial and related uses. Mount Laurel has set aside almost 30% of its area, over 4,100 acres, for that purpose; the only residential use allowed is for farm dwellings. In almost a decade only about 100 acres have been developed industrially. Despite the township's strategic location for motor transportation purposes, as intimated earlier, it seems plain that the likelihood of anywhere near the whole of the zoned area being used for the intended purpose in the foreseeable future is remote indeed and that an unreasonable amount of land has thereby been removed from possible residential development, again seemingly for local fiscal reasons.

Without further elaboration at this point, our opinion is that Mount Laurel's zoning ordinance is presumptively contrary to the general welfare and outside the intended scope of the zoning power in the particulars mentioned. A facial showing of invalidity is thus established, shifting to the municipality the burden of establishing valid superseding reasons for its action and non-action. We now examine the reasons it advances.

The township's principal reason in support of its zoning plan and ordinance housing provisions, advanced especially strongly at oral argument, is the fiscal one previously adverted to, i.e., that by reason of New Jersey's tax structure which substantially finances municipal governmental and educational costs from taxes on local real property, every municipality may, by the exercise of the zoning power, allow only such uses and to such extent as will be beneficial to the local tax rate. In other words, the position is that any municipality may zone extensively to seek and encourage the "good" tax ratables of industry and commerce, and limit the permissible types of housing to those having the fewest school children or to those providing sufficient value to attain or approach paying their own way taxwise.

We have previously held that a developing municipality may properly zone for and seek industrial ratables to create a better economic balance for the community vis-a-vis educational and governmental costs engendered by residential development, provided that such was "* * * done reasonably as part of and in furtherance of a legitimate comprehensive plan for the zoning of the entire municipality." Gruber v. Mayor and Township Committee of Raritan Township, 39 N.J. 1 , 9-11 (1962). We adhere to that view today. But we were not there concerned with, and did not pass upon, the validity of municipal exclusion by zoning of types of housing and kinds of people for the same local financial end. We have no hesitancy in now saying, and do so emphatically, that, considering the basic importance of the opportunity for appropriate housing for all classes of our citizenry, no municipality may exclude or limit categories of housing for that reason or purpose. While we fully recognize the increasingly heavy burden of local taxes for municipal governmental and school costs on homeowners, relief from the consequences of this tax system will have to be furnished by other branches of government. It cannot legitimately be accomplished by restricting types of housing through the zoning process in developing municipalities.

The propriety of zoning ordinance limitations on housing for ecological or environmental reasons seems also to be suggested by Mount Laurel in support of the one-half acre minimum lot size in that very considerable portion of the township still available for residential development. It is said that the area is without sewer or water utilities and that the soil is such that this plot size is required for safe individual lot sewage disposal and water supply. The short answer is that, this being flat land and readily amenable to such utility installations, the township could require them as improvements by developers or install them under the special assessment or other appropriate statutory procedure. The present environmental situation of the area is, therefore, no sufficient excuse in itself for limiting housing therein to single-family dwellings on large lots. Cf. National Land and Investment Co. v. Kohn, 419 Pa. 504, 215 A.2d 597 (1965). This is not to say that land use regulations should not take due account of ecological or environmental factors or problems. Quite the contrary. Their importance, at last being recognized, should always be considered. Generally only a relatively small portion of a developing municipality will be involved, for, to have a valid effect, the danger and impact must be substantial and very real (the construction of every building or the improvement of every plot has some environmental impact) — not simply a makeweight to support exclusionary housing measures or preclude growth — and the regulation adopted must be only that reasonably necessary for public protection of a vital interest. Otherwise difficult additional problems relating to a "taking" of a property owner's land may arise. See AMG Associates v. Township of Springfield, 65 N.J. 101, 112, n. (4) (1974).

By way of summary, what we have said comes down to this. As a developing municipality, Mount Laurel must, by its land use regulations, make realistically possible the opportunity for an appropriate variety and choice of housing for all categories of people who may desire to live there, of course including those of low and moderate income. It must permit multi-family housing, without bedroom or similar restrictions, as well as small dwellings on very small lots, low cost housing of other types and, in general, high density zoning, without artificial and unjustifiable minimum requirements as to lot size, building size and the like, to meet the full panoply of these needs. Certainly when a municipality zones for industry and commerce for local tax benefit purposes, it without question must zone to permit adequate housing within the means of the employees involved in such uses. (If planned unit developments are authorized, one would assume that each must include a reasonable amount of low and moderate income housing in its residential "mix," unless opportunity for such housing has already been realistically provided for elsewhere in the municipality.) The amount of land removed from residential use by allocation to industrial and commercial purposes must be reasonably related to the present and future potential for such purposes. In other words, such municipalities must zone primarily for the living welfare of people and not for the benefit of the local tax rate.

We have earlier stated that a developing municipality's obligation to afford the opportunity for decent and adequate low and moderate income housing extends at least to "* * * the municipality's fair share of the present and prospective regional need therefor." Some comment on that conclusion is in order at this point. Frequently it might be sounder to have more of such housing, like some specialized land uses, in one municipality in a region than in another, because of greater availability of suitable land, location of employment, accessibility of public transportation or some other significant reason. But, under present New Jersey legislation, zoning must be on an individual municipal basis, rather than regionally. So long as that situation persists under the present tax structure, or in the absence of some kind of binding agreement among all the municipalities of a region, we feel that every municipality therein must bear its fair share of the regional burden. (In this respect our holding is broader than that of the trial court, which was limited to Mount Laurel-related low and moderate income housing needs.)

The composition of the applicable "region" will necessarily vary from situation to situation and probably no hard and fast rule will serve to furnish the answer in every case. Confinement to or within a certain county appears not to be realistic, but restriction within the boundaries of the state seems practical and advisable. (This is not to say that a developing municipality can ignore a demand for housing within its boundaries on the part of people who commute to work in another state.) Here we have already defined the region at present as "those portions of Camden, Burlington and Gloucester Counties within a semicircle having a radius of 20 miles or so from the heart of Camden City." The concept of "fair share" is coming into more general use and, through the expertise of the municipal planning adviser, the county planning boards and the state planning agency, a reasonable figure for Mount Laurel can be determined, which can then be translated to the allocation of sufficient land therefor on the zoning map. See generally, New Jersey Trends, ch. 27, Listokin, Fair Share Housing Distribution: An Idea Whose Time Has Come?, p. 353. We may add that we think that, in arriving at such a determination, the type of information and estimates, which the trial judge ( 119 N.J. Super. at 178) directed the township to compile and furnish to him, concerning the housing needs of persons of low and moderate income now or formerly residing in the township in substandard dwellings and those presently employed or reasonably expected to be employed therein, will be pertinent.

There is no reason why developing municipalities like Mount Laurel, required by this opinion to afford the opportunity for all types of housing to meet the needs of various categories of people, may not become and remain attractive, viable communities providing good living and adequate services for all their residents in the kind of atmosphere which a democracy and free institutions demand. They can have industrial sections, commercial sections and sections for every kind of housing from low cost and multi-family to lots of more than an acre with very expensive homes. Proper planning and governmental cooperation can prevent over-intensive and too sudden development, insure against future suburban sprawl and slums and assure the preservation of open space and local beauty. We do not intend that developing municipalities shall be overwhelmed by voracious land speculators and developers if they use the powers which they have intelligently and in the broad public interest. Under our holdings today, they can be better communities for all than they previously have been.

III

The Remedy

As outlined at the outset of this opinion, the trial court invalidated the zoning ordinance in toto and ordered the township to make certain studies and investigations and to present to the court a plan of affirmative public action designed "to enable and encourage the satisfaction of the indicated needs" for township related low and moderate income housing. Jurisdiction was retained for judicial consideration and approval of such a plan and for the entry of a final order requiring its implementation.

We are of the view that the trial court's judgment should be modified in certain respects. We see no reason why the entire zoning ordinance should be nullified. Therefore we declare it to be invalid only to the extent and in the particulars set forth in this opinion. The township is granted 90 days from the date hereof, or such additional time as the trial court may find it reasonable and necessary to allow, to adopt amendments to correct the deficiencies herein specified. It is the local function and responsibility, in the first instance at least, rather than the court's, to decide on the details of the same within the guidelines we have laid down. If plaintiffs desire to attack such amendments, they may do so by supplemental complaint filed in this cause within 30 days of the final adoption of the amendments.

We are not at all sure what the trial judge had in mind as ultimate action with reference to the approval of a plan for affirmative public action concerning the satisfaction of indicated housing needs and the entry of a final order requiring implementation thereof. Courts do not build housing nor do municipalities. That function is performed by private builders, various kinds of associations, or, for public housing, by special agencies created for that purpose at various levels of government. The municipal function is initially to provide the opportunity through appropriate land use regulations and we have spelled out what Mount Laurel must do in that regard. It is not appropriate at this time, particularly in view of the advanced view of zoning law as applied to housing laid down by this opinion, to deal with the matter of the further extent of judicial power in the field or to exercise any such power. See, however, Pascack Association v. Mayor and Council of Township of Washington, 131 N.J. Super. 195 (Law Div. 1974), and cases therein cited, for a discussion of this question. The municipality should first have full opportunity to itself act without judicial supervision. We trust it will do so in the spirit we have suggested, both by appropriate zoning ordinance amendments and whatever additional action encouraging the fulfillment of its fair share of the regional need for low and moderate income housing may be indicated as necessary and advisable. (We have in mind that there is at least a moral obligation in a municipality to establish a local housing agency pursuant to state law to provide housing for its resident poor now living in dilapidated, unhealthy quarters.) The portion of the trial court's judgment ordering the preparation and submission of the aforesaid study, report and plan to it for further action is therefore vacated as at least premature. Should Mount Laurel not perform as we expect, further judicial action may be sought by supplemental pleading in this cause.

The judgment of the Law Division is modified as set forth herein. No costs.