Ante-chapel is the term given to that portion of a chapel

Chapel

A chapel is a building used by Christians as a place of fellowship and worship. It may be part of a larger structure or complex, such as a church, college, hospital, palace, prison or funeral home, located on board a military or commercial ship, or it may be an entirely free-standing building,...

 which lies on the western side of the choir screen.

In some of the colleges at Oxford

University of Oxford

The University of Oxford is a university located in Oxford, United Kingdom. It is the second-oldest surviving university in the world and the oldest in the English-speaking world. Although its exact date of foundation is unclear, there is evidence of teaching as far back as 1096...

 and Cambridge

University of Cambridge

The University of Cambridge is a public research university located in Cambridge, United Kingdom. It is the second-oldest university in both the United Kingdom and the English-speaking world , and the seventh-oldest globally...

 the ante-chapel is carried north and south across the west end of the chapel, constituting a western transept

Transept

For the periodical go to The Transept.A transept is a transverse section, of any building, which lies across the main body of the building. In Christian churches, a transept is an area set crosswise to the nave in a cruciform building in Romanesque and Gothic Christian church architecture...

 or narthex

Narthex

The narthex of a church is the entrance or lobby area, located at the end of the nave, at the far end from the church's main altar. Traditionally the narthex was a part of the church building, but was not considered part of the church proper...

. This model, based on Merton College chapel (13th century), of which only chancel and transept were built though a nave

Nave

In Romanesque and Gothic Christian abbey, cathedral basilica and church architecture, the nave is the central approach to the high altar, the main body of the church. "Nave" was probably suggested by the keel shape of its vaulting...

 was projected, was followed at Wadham

Wadham College, Oxford

Wadham College is one of the constituent colleges of the University of Oxford in the United Kingdom, located at the southern end of Parks Road in central Oxford. It was founded by Nicholas and Dorothy Wadham, wealthy Somerset landowners, during the reign of King James I...

, New

New College, Oxford

New College is one of the constituent colleges of the University of Oxford in the United Kingdom.- Overview :The College's official name, College of St Mary, is the same as that of the older Oriel College; hence, it has been referred to as the "New College of St Mary", and is now almost always...

 and Magdalen

Magdalen College, Oxford

Magdalen College is one of the constituent colleges of the University of Oxford in England. As of 2006 the college had an estimated financial endowment of £153 million. Magdalen is currently top of the Norrington Table after over half of its 2010 finalists received first-class degrees, a record...

 Colleges, Oxford, in the new chapel of St John's College, Cambridge

St John's College, Cambridge

St John's College is a constituent college of the University of Cambridge. The college's alumni include nine Nobel Prize winners, six Prime Ministers, three archbishops, at least two princes, and three Saints....

, and in Eton College

Eton College

Eton College, often referred to simply as Eton, is a British independent school for boys aged 13 to 18. It was founded in 1440 by King Henry VI as "The King's College of Our Lady of Eton besides Wyndsor"....

. In Jesus College, Cambridge

Jesus College, Cambridge

Jesus College is a constituent college of the University of Cambridge, England.The College was founded in 1496 on the site of a Benedictine nunnery by John Alcock, then Bishop of Ely...

, the transept and a short nave constitute the ante-chapel; in Clare College an octagonal vestibule serves the same purpose; and in Christ's

Christ's College, Cambridge

Christ's College is a constituent college of the University of Cambridge.With a reputation for high academic standards, Christ's College averaged top place in the Tompkins Table from 1980-2000 . In 2011, Christ's was placed sixth.-College history:...

, Trinity

Trinity College, Cambridge

Trinity College is a constituent college of the University of Cambridge. Trinity has more members than any other college in Cambridge or Oxford, with around 700 undergraduates, 430 graduates, and over 170 Fellows...

 and King's

King's College, Cambridge

King's College is a constituent college of the University of Cambridge, England. The college's full name is "The King's College of our Lady and Saint Nicholas in Cambridge", but it is usually referred to simply as "King's" within the University....

 Colleges, Cambridge, the ante-chapel is a portion of the main chapel, divided off from the chancel

Chancel

In church architecture, the chancel is the space around the altar in the sanctuary at the liturgical east end of a traditional Christian church building...

by the choir screen.