The Annex was constructed in 1988 to serve as temporary offices for biology faculty when over-crowding became a problem in the Peter Engel Science Center.  When the new bench biology facility was constructed, the Annex was re-located and served for a time as a student residence - the residents enjoying the spacious rooms and the air conditioning.

During the renovation of the first floor of the main Quadrangle, the Annex served as temporary "camp-out" sites for various administrative areas as their portion of the Quad was renovated.

In Summer of 2007, the Annex will begin to house the studies of scholars who are in residence at The Collegeville Institute for Ecumenical and Cultural Research.

Annex