Halakhic Positions of Rav Joseph B. Soloveitchik
by R. Aharon Ziegler
According to Rav Soloveitchik, it is customary to stand during certain parts of Tefilla, or during recitation of specific Piyyutim, but not because the Aron HaKodesh is opened. The Aron HaKodesh is considered a different Reshut (domain) from the rest of the synagogue even when it is opened and there is no obligation to stand out of respect for a Sefer Torah when it is in a different Reshut. (Yoreh De’ah 282:1, and Taz #1).
Rather, we stand because certain Piyyutim resemble a “Davar She’bikdusha”, in that they entail a public responsive reading of praises to HaShem, and there IS an obligation to stand during the recitation of such prayers.