5.E.5 Place of Confession and Confession
1. “‘The proper place to hear sacramental confessions is a church or an oratory’ though it remains clear that pastoral reasons can justify celebrating the Sacrament in other places.” 
2. Every parish should offer the opportunity for a “penance chapel” atmosphere for the celebration of penance. This should be a room dedicated solely for this purpose and which is clearly visible to the congregation. There should be glass (on the door) so that the interior is visible.
3. However, provision is to be made that either the confessor or the penitent can exercise the right that each possesses to make use of a fixed grill or screen in the celebration of the sacrament. 
 Pope John Paul II, m.p. apostolic letter on Certain Aspects of the Celebration of the Sacrament of Penance, Misericordia Dei (May 2, 2002) n. 9a. Available at Vatican website. [Hereafter Misericordia Dei.]
Also see c. 964 §1, §3.
 c. 964 §2. Misericordia Dei, 9b. USCCB complementary norm on canon 964§2 (November 17, 1999). Available at USCCB website. Also see Pontifical Council for the Interpretation of Legislative Texts, Responsa ad propositum dubium: de loco excipiendi sacramentales confessiones (7 July 1998): AAS 90  711.