noun
access restriction; entry restriction
Refers to limiting or controlling entry to a room, building, or indoor space, often for security, capacity, or privacy reasons.
このエリアは入室制限がかかっているので、関係者以外は入れません。
This area is under access restriction, so only authorized personnel may enter.
サーバールームには入室制限が設けられている。
Access to the server room is restricted.
立ち入り禁止 is a stronger, more absolute prohibition (no entry), while 入室制限 implies controlled or limited access rather than a complete ban.
Compound of 入室 (entering a room) and 制限 (restriction, limitation).