NYTimes
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 M. Jacob, who runs a co-op on the Lower East Side 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 Friday evening until Saturday evening so that observant Jews do not have to press any buttons.[...]
YNet discussion of the recent ruling YNet new developments
The issue of Shabbos elevators - after the acceptance of the view of Rav Shlomo Zalman Auerbach as a tolerated leniency for many years - has recently been brought into crises by a ruling by leading chareidi rabbis saying that there is now no basis for being lenient. The following is a teshuva written by Rav Meir Triebitz which addresses their concerns. It has been carefully reviewed by Rav Moshe Sternbuch. Rav Sternbuch has personally sent it to those who recently prohibited the Shabbos elevators. This does not mean of course that Rav Sternbuch necessarily agrees with the conclusions but only that the teshuva is worthwhile considering.
Afikei Torah 5 R Triebetz Elevator