Appellants own and occupy a residential dwelling in the Borough of Northvale. In 1981 they commenced construction of an addition to their home. Neighbors objected on the ground that the Borough’s zoning code expressly prohibited two-family dwellings in all zones. The issue is whether the proposed structure resulted in a violation of that prohibition. The North-vale Board of Adjustment (Board) concluded that the addition would produce a violation. The Law Division reversed that determination. However, the Appellate Division, in an unreported opinion, agreed with the conclusion of the Board that there was indeed a violation and hence reversed the Law Division. We granted certification, 97 N.J. 587 (1984), and now affirm.
I
Appellants, John and Nina Gonchar, reside at 426 Briarwood Lane in Northvale. Carl and Adrianne Rowatti reside next door at number 428. The Gonchars wished to build an addition onto their house so that Mrs. Gonchar’s widowed mother could *48live with them. They made application for this addition and submitted the necessary building plans, which were prepared by an architect, to the Northvale Building Inspector. On the application form itself the Gonchars described the structure as a “mother and daughter new addition.” The Northvale Inspector issued a building permit to the Gonchars on October 5, 1981.
The Rowattis first became aware of the appellants’ construction plans on October 23, 1981. On that date the Rowattis noticed that an excavating machine had begun digging in close proximity to the boundary line between the two properties. Mr. Rowatti informed Mr. Gonchar of his belief that the digging appeared to be in violation of local sideyard requirements. Notwithstanding this uncertainty as to the location of the property line, the Gonchars proceeded to pour the footings on October 24, 1981. Shortly thereafter the property was staked and it was indeed shown that the owners’ reliance on an old survey had resulted in a sideyard violation. The Gonchars applied for a sideyard variance, which was granted by resolution of the Board on November 19, 1981.
Following the Board’s grant of the sideyard variance, the Rowattis attended a meeting of the Northvale Mayor and Council to protest that the appellants’ addition amounted to a two-family or multi-family dwelling in violation of the municipality’s zoning ordinance. In a letter dated November 28, 1981, a zoning official informed the Gonchars that the addition to their house constituted a violation of the Northvale zoning laws, and that all construction work on this facility had to stop immediately. The official later modified his order to allow the owners to resume construction pending a full review by the Board.
The Gonchars formally appealed the order of the zoning official to the entire Board in accordance with N.J.S.A. 40:55D-70, which states in part:
The board of adjustment shall have the power to:
*49а. Hear and decide appeals where it is alleged by the appellant that there is error in any order, requirement, decision or refusal made by an administrative officer based on or made in the enforcement of the zoning ordinance * * *.
The owners appeared before the Board not to seek a variance for a nonconforming use but simply to receive a determination as to whether the addition would render the building a two-family dwelling.
After hearing the testimony of Mrs. Gonchar and Mr. Rowatti, in addition to the testimony of a real estate broker, a realtor, and the contractor who actually built the facility, the Board determined that the structure was a multi-family dwelling. In reaching this determination, the Board made the following findings:
1. That the purpose of the proposed addition would be to accommodate the applicant’s mother who is a widow aged 74 years, and presently resides in a home in Avalon, New Jersey.
2. That it is the intent of the applicant that the proposed premises would be occupied only by a member of their family, namely, the applicant’s widowed mother.
3. That the applicant was granted a variance by the Board of Adjustment on November 19, 1981 for a side-yard variance * * *.
4. That a stop-work order was issued by the Zoning Officer of the Borough of Northvale on November 27, 1981 and that the applicant continued work at their own risk as stipulated by Counsel.
5. The proposed addition * * * contains a separate bedroom, separate living room, separate kitchen with its own entranceway from the front of the building entering into a foyer, and also containing a full bathroom. The proposed kitchen in the addition is larger than the kitchen in the present existing structure. It shall contain its own closets and enclosed washer, and heating system with its own boiler.
б. There is also a second entrance from the porchway of the proposed structure, and a passageway between the main building and the addition.
7. The present garage will exist between the present structure and the proposed addition.
8. The utility lines will be the same as the main structure as well as the sewer lines. Presently, there are four occupants of the present structure: mother and father, and two children.
9. Part of the present structure will be altered.
10. That there will be no separate electric service, the existing meters will remain, but be relocated; the same gas service, and no separate water line.
11. There shall be a new furnace and hot water heater due to the fact that the existing system would be inadequate to accommodate this new addition.
*5012. The subject premises are located within a Residential 12.5 Zone District, providing for occupancy by not more than one family dwellings.
13. That the Zoning Officer, upon inspection of the premises, issued a letter directing the applicants to stop work immediately on November 27, 1981 based upon his interpretation that the plans indicated a multiple family dwelling, which is expressly prohibited in this Residential District.
14. That a number of neighbors in the surrounding dwellings objected to the structure as a multi-dwelling [sic].
The Board, by a vote of six to one, adopted a resolution memorializing its decision on December 17, 1981.
Thereafter, both the neighbors and owners appealed to the Law Division. The Rowattis sought review of the Board’s approval of the sideyard variance, while the Gonchars appealed the Board’s determination as to the status of the structure itself. On January 19, 1982, prior to the case being heard, the Law Division entered an order permitting the Gonchars to complete construction at their own risk. The court then affirmed the Board’s approval of the sideyard variance; however, it disagreed with the Board that the structure amounted to a multi-family dwelling. The Appellate Division affirmed the Law Division with regard to the sideyard issue, which is not before us, the Rowattis not having sought review on that question; but it reversed on the issue of whether the addition converted the owners’ home into a two-family or multi-family residence.
II
The ordinance in question provides that
[t]he following uses are expressly prohibited in all zones in the Borough of Northvale:
(2) Apartment houses, garden apartments, boarding-houses or any type of multi-family usage, two-family homes, duplex or double houses [Northvale, N.J., Code § 74-11 (1981).]
The municipal Code defines a one-family dwelling as “a separate building designed for or occupied exclusively by one (1) family.” The ordinance defines a multiple dwelling as “a *51building designed [for] or occupied by more than one (1) family.” Id. Finally, a “family” is defined in the Code as
[o]ne (1) or more persons related by blood, adoption or marriage, including foster children, living and cooking together as a single housekeeping unit, exclusive of household servants, or a number of persons, but not exceeding three (3), living and cooking together as a single housekeeping unit, where one (1) or more of such persons are not related by blood, adoption or marriage to others * * *. [Id.]
Nowhere does the ordinance recognize or define a “mother and daughter new addition,” the language the Gonchars used on their building application to describe the structure 1.
Our concern today centers on the definition of a two-family or multi-family dwelling, which is at the heart of this appeal. The addition to the Gonchars’ home contains a foyer, bathroom, bedroom, living room, kitchen, and utility room. It also has its own closets, boiler, and heating system. The addition measures 660 square feet, has its own separate entranceway, and its kitchen is in fact larger than the kitchen in the original structure. In viewing that totality of facts and the design of the addition itself, the Board of Adjustment determined that the structure “point[ed] clearly to the establishment of a fully separate and complete apartment * * * [so] as to constitute a separate dwelling.”
In affirming the Board’s determination, we first acknowledge the standard of review that is applicable to a case of this type. It is well established that an appellate court will uphold the factual determinations of an administrative agency “[i]f there is sufficient credible evidence to support those conclusions * * Goodman v. London Metals Exch., Inc., 86 N.J. 19, 28 (1981); *52accord. Close v. Kordulak Bros., 44 N.J. 589 (1965). Particularly in cases in which a board of adjustment’s denial of a zoning variance is at issue, the action of the board of adjustment is presumptively correct and its denial will not be overturned unless it is unreasonable, arbitrary, or capricious. E.g., Rexon v. Board of Adjustment of Haddonfield, 10 N.J. 1, 7 (1952). Although the denial of a variance is not at issue here, the Board’s factual conclusions are entitled to great weight and, like those of an administrative body, ought not be disturbed unless there is insufficient evidence to support them. Cf. Commons v. Westwood Zoning Bd. of Adjustment, 81 N.J. 597, 610 (1980) (“We have frequently advised boards of adjustment to make findings predicated upon factual support in the record and directed to the issues involved.”).
There is ample evidence in the record to support the Board’s conclusion that the Gonchars’ addition converted their residence from a one-family to a multi-family dwelling. The Board heard the testimony of an area realtor who testified that from a purely physical standpoint, the addition made the home a two-family dwelling. The realtor also stated that if enough of the same kind of residences were constructed on or near Briarwood Lane, that circumstance would alter the zoning scheme for that entire part of Northvale.
Our research uncovers only sparse authority dealing with the definition of a two-family or multi-family dwelling. In Williams v. Adami, 70 Misc.2d 702, 334 N.Y.S.2d 539 (1972), the court affirmed the determination of a local zoning board that the addition of a second kitchen and half bath in a one-family residence would convert that structure into a two-family dwelling. The court stated that it agreed with the Board’s conclusion “as a matter of logic,” and that in any event, “the interpretation by the Board was not arbitrary and unreasonable, its findings were supported by the record, and hence, should not be set aside.” Id. at 707, 334 N.Y.S.2d at 544 (citation omitted).
*53A somewhat different result was reached in Stafford v. Incorporated Village of Sands Point, 200 Misc. 57, 102 N.Y.S.2d 910 (1951). There, the court determined that the structure at issue was a one-family residence, notwithstanding the existence of two kitchens and the presence on the premises of the owner’s mother and sister. However, the applicable statute, Section 4(6) of the Multiple Dwellings Law, provided that “a building designed for and occupied exclusively by two families is a ‘two-family’ dwelling,” and a “single-family private dwelling” is a building “designed for and occupied exclusively by one family.” Id. at 59, 102 N.Y.S.2d at 913 (emphasis added). The court concluded that under the accepted definition of the Dwellings Law
neither the design of the house nor the nature of its occupancy standing alone controls. The combination of the design of the house and the nature of the occupancy is the two-fold test.
It would seem that as far as occupancy goes, to classify premises as a two-family house there would have to be two separate families not living together as a unit. The using of a dwelling for living purposes by a son [the owner], his family * * * and his mother and sister, in the absence of evidence to the contrary, may not be said to be the setting up of two separate family units who are living not under a single head or management for the purpose of denying a certificate of occupancy in a one family district. [Id. at 59, 102 N.Y.S.2d at 913 (emphasis in original).]
Thus, because only family members would be living in the building, the court did not find that the design of the residence converted it into a two-family dwelling.
In contrast, section 74-5 of the Northvale ordinance, as noted earlier, defines a multiple dwelling as “[a] building designed [for] or occupied by more than one (1) family” (emphasis added). Clearly, the use of the word “or” creates a different test from that applied in Stafford. The Board found that the Gonchars’ addition constituted “a fully separate and complete apartment for the occupancy of one person,” which is simply another way of stating that it is designed for more than one family. Hence, it is the design of the dwelling itself that is violative of the Northvale code, irrespective of who may be living there at this or any future time.
*54The ordinance’s definition of “family” also supports the Board’s determination that the structure at issue is a two-family or multifamily dwelling.2 As noted earlier, supra at 51-51, the Code defines “family” in terms not only of relationship but of group activity, as one or more persons “living and cooking together as a single housekeeping unit.” In Missionaries of Our Lady of La Salette v. Village of Whitefish Bay, 267 Wis. 609, 66 N.W.2d 627 (1954), a group of three priests and two lay brothers resided together in a large house that was situated in a single-family zone. The trial court found that each person living in the house had his own separate bedroom and that all of the residents ate their meals “at the same table served by one kitchen.” Id. at 611, 66 N.W.2d at 629. On these facts, the Supreme Court of Wisconsin determined that the residents were “liv[ing], sleeping], cook[ing] and eat[ing] on the premises as a single housekeeping unit.” Id. at 616, 66 N.W.2d at 631.
The situation revealed by the record in this case, however, is markedly different. Mrs. Gonchar testified on direct examination before the Board that one of the prime purposes behind the construction of the addition was to provide “free access * * * between the rooms that we [the owners] occupy and what my mother will occupy.” Mrs. Gonchar also explained:
*55She [the mother] can come over, stay for hours, stay for minutes. She’ll know what we are doing, who’s going where, participate in our discussion. We can go over there, again for minutes or for hours, whatever. She doesn’t have to feel afraid if she gets sick. I can stop over for a few minutes, we can eat together. We can eat separately, whatever.
We conclude that what Mrs. Gonchar herself envisioned, and what has indeed resulted from the construction of this addition, is something beyond a single housekeeping unit.
To summarize, several factors lead us to the conclusion that the addition converted the owners’ residence into a two-family or multifamily dwelling and allows both the owners and the occupant of the addition itself to live as more than a single housekeeping unit. First, with its separate kitchen, boiler, bathroom, heating system, and entranceway, the addition can function independently from the original residence. Second, there is the closely-related factor that because of its design and physical appearance, the addition may impair the intent and purpose of the zoning plan for the entire area around Briar-wood Lane. Third, the owners themselves contemplate an arrangement that would provide Mrs. Gonchar’s mother,with the opportunity to live and cook separately from the rest of the family whenever she so desires. Finally, as a matter of judicial review, local boards of adjustment must be accorded great latitude in determining facts that may adversely affect a municipality’s entire zoning scheme.
We are sensitive to the fact that at the heart of this case there lies a daughter’s concern for an elderly parent. Indeed, this Court has recognized that the older members of our society must deal with a number of special problems, particularly in the area of housing. See Taxpayers Ass’n of Weymouth Township v. Weymouth Township, 80 N.J. 6, 24-30 (1976), cert. denied, 430 U.S. 977, 97 S.Ct. 1672, 52 L.Ed.2d 373 (1977). We would like to think that our concern for the profound social problems associated with increasing life-expectancies and calculating housing costs is at least as great as that of our dissenting colleague. But we do not view this case as presenting the vehicle by which to address those concerns. At oral argument *56before us, on at least two occasions in response to questions from different members of the Court, counsel specifically and unmistakably eschewed any constitutional attack on the ordinance. No constitutional challenge was made in any of the proceedings below. Moreover, we are not presented with an ordinance that seeks to regulate or restrict the use of land on the basis of the user’s age.3 The Northvale ordinance seeks merely to prohibit a certain type of structure, irrespective of the owners’ or occupants’ ages, or any other classification. Nor are principles of estoppel applicable here. The Gonchars were on notice at several different phases of the construction that they were proceeding at their own risk. Unfortunately, the risk materialized into an actual violation of the Northvale code that the Board of Adjustment correctly recognized.
When, as in this case, the Court is confronted with an ordinance that contains provisions that are, as the dissenter observes, arguably inconsistent, post at 61, our obligation is to reconcile those provisions, to read them so as to make sense of them, and then to apply the ordinance in accordance with the intent of the municipality. It is clear to us that the intent of the Northvale ordinance is that when a residential structure is capable of housing two completely independent family units in the kind of lifestyle that, as a matter of fact, characterizes such independent living as defined in the ordinance, the entity is then a multiple dwelling; as such, it is prohibited.
Affirmed.
We are informed that after the events giving rise to this litigation, the Borough enacted an amendment to its zoning ordinance to provide for the expansion or alteration of a dwelling unit to accommodate, as a conditional use, a "mother-daughter dwelling unit.” Appellants do not contend that the addition at issue here satisfies the requirements of the amended ordinance; hence, we need not be concerned with any application of the time-of-decision rule. See, e.g., Kruvant v. Mayor & Council of Cedar Grove, 82 N.J. 435, 440 (1980).
We note only in passing, since it does not relate to the issues on this appeal, that one aspect of the definition of a family in the Northvale ordinance is constitutionally infirm. In State v. Baker, 81 N.J. 99, 113 (1979), this Court stated that "zoning regulations [that] attempt to limit residency based upon the number of unrelated individuals present in a single non-profit housekeeping unit cannot pass constitutional muster." Hence, inasmuch as it seeks to limit a household unit to no more than three persons "where one (1) or more of such persons are not related by blood, adoption or marriage,” the Northvale code is invalid under our decision in Baker. For a more detailed discussion of the problems of defining "family" for zoning purposes, see Baker, 81 N.J. at 107-13; Annot., 12 A.L.R. 4th 238 (1982); Comment, "Single-Family Zonings: Ramifications of State Court Rejection of Belle Terre on Use and Density Control," 32 Hastings L.J. 1687 (1982); "Developments in the Law — Zoning,” 91 Harv.L.Rev. 1427, 1568-74 (1978).
To be sure, age-restrictive zoning ordinances do exist and present a different line of analysis from that which is warranted here. For background on these age-related issues, see J.G. Richards, “Zoning for Direct Social Control,” 1982 Duke L.J. 761, 799-828.