Does sin accrue to one who prays alone in his sleeping quarters, if there is a mosque in the military barracks where the Dhuhr prayer is performed in congregation, while it is closed at the times of Fajr, Maghrib, and Isha prayers, and is only occasionally opened for the Asr prayer?

Scholars differed concerning the ruling on congregational prayer (Salat al-Jama'ah). What is chosen by us is that it is obligatory upon able-bodied, adult men, and whoever intentionally abandons it commits a sin. You must go to perform the congregation in the mosque, or you can perform it with your companions at your place of residence. If you follow those who consider it to be recommendable, then there is no sin upon you, but the virtue of congregation is immense.