Each building at the Cooperative Village complex in Manhattan has two elevators, one of them programmed for the Sabbath so observant Jews don't have to push any buttons. Now, though, the use of such elevators has been challenged.

NEW YORK — Tangible things occupy the days of most building managers in New York City. Hot water, floods, bugs, rent checks and so on.

But last week, newly added to the tenant issues facing building managers like Harold Jacob, who runs a co-op where Orthodox Jews inhabit a substantial portion of the 2,500 apartments, was this almost ontological question:

Does that elevator “know” how many people are on it?

The question is at the core of a ruling issued by a group of prominent rabbis in Israel on Sept. 29 that seems to ban the use of many so-called “Shabbos elevators” — elevators fixed to stop on every floor from sunset Friday until sunset Saturday so that observant Jews do not have to press any buttons.

Since the 1960s, when high-rise apartment buildings became ubiquitous, the Orthodox rabbinate has made such elevators one of the few exceptions to Talmudic rules prohibiting 39 categories of activity on the Sabbath, including manual labor or the use of electrical devices. Like flipping a light switch, pressing an elevator button is considered the use of an electrical device.

Though many ultra-Orthodox Jews have always considered Shabbos elevators illegitimate, a vast majority of the observant, especially the elderly or infirm, and large Orthodox families living with small children on upper floors of high rise buildings, have used them since around 1964, when prominent rabbinical scholars reached a consensus published in religious journals.

But the recent ruling introduced a caveat based on new technology in elevators.

The rabbis doing the ruling did not name the offending technology. But for several years there has been debate among Orthodox rabbis in Israel over whether devices that measure the weight inside an elevator car, and adjust power accordingly, effectively make entering a car the equivalent of pressing a button.