to the State Communities Aid Association (SCAA), a professional lobbying group, for use as a business office. Petitioner Center Square Association, Inc., a not-for-profit corporation seeking to rehabilitate housing in the Center Square area, filed a complaint with the Commissioner of the Building Department of the City of Albany, requesting that the proposed use by SCAA be restrained as not authorized by the zoning ordinance. The commissioner denied this request, stating that the use of the first floor as a business office was a continuation of a nonconforming use, with “no qualitative change *** in terms of volume, density, appearance or structure”. Thereafter, petitioners Center Square Association, Inc., and various Center Square area residents appealed to the board of building and zoning appeals. Following a hearing, the board denied petitioners’ application, concluding that a lawful nonconforming use of the building for office purposes existed at the time of enactment of the 1924 Zoning Ordinance, continued to the present time, and included the intended operation by SCAA. Petitioners then commenced this article 78 proceeding to annul the board’s determination. Special Term dismissed the petition, and this appeal followed. Petitioners first contend that under the 1924 zoning ordinance, use of the first floor of the building as a medical office was not a nonconforming use, but was lawful as a “home occupation”. The 1924 zoning ordinance permitted the office of a physician in a residential zone when the office was “situated in the same dwelling or apartment used by such physician * * * as his private dwelling” (former Zoning Ordinance, City of Albany, p 292). Petitioners contend that Dr. Winne’s use of the building fit this description because at the time the 1924 ordinance was enacted, he maintained a medical office on the first floor of the building and resided in an upstairs apartment. Moreover, he was the only physician listed for the premises until 1935, at which time other physicians also began to be listed at that address. Respondents argue, however, that Dr. Winne’s use of the building was not consistent with the definition of “home occupation”. They note that at all times between 1916 and 1924 there were two apartments in the building, with Dr. Winne living in only one and various other people residing in the second. Furthermore, there is evidence in the record that prior to 1924 Dr. Winne had several other physicians in his office. They were not listed in the city directory, apparently because they were working for Dr. Winne. An interpretation of “home occupation” by the board, the local agency responsible for the administration of the zoning ordinance, must be upheld if it is neither irrational nor unreasonable
(Matter of Albert v Board of Stds. & Appeals of City ofN. Y., 89 AD2d 960 , 962). We cannot say that it was irrational to find that a building which contains two apartments and an office employing several physicians is a more extensive operation than the zoning board intended to be included in its definition of “home occupation”. Thus, the board’s finding that, at the time the 1924 ordinance was enacted, the medical office was a lawful nonconforming use must be sustained. Petitioners next contend that allowing a lobbying group to use the office in 1980 was not a continuation of a lawful nonconforming use, but, instead, an improper substitution of one nonconforming use for another. There is clearly a public policy to restrict nonconforming uses in order ultimately to eliminate them
(Matter of Cave v Zoning Bd. of Appeals of Vil. ofFredonia, 49 AD2d 228 , 233, mot for lv to app den 38 NY2d 710 ). Therefore, while an established lawful nonconforming use may be continued, it may not be exchanged for a different nonconforming use (1 Anderson, New York Zoning Law and Practice [2d ed, § 6:21, p 202;
Matter of Calcagni Constr. Co. v Zoning Bd. of Appeals of Town & Vil. of Harrison, 56 AD2d 845 ). Determining whether a particular use is a continuation of or a change in a nonconforming use is a factual determination for the board in each case (see 4 Rathkopf, Law of Zoning and Planning [4th ed], pp 58-18 — 58-24). A continuation of use exists where the use is “substantially the