|Fr Bede Rowe - Chantry Priest|
From the Catholic Encyclopedia
It was thus essentially, though not solely, a liturgical institution requiring as a sine qua non of its existence a place where the incumbent might say Mass. As a rule this was provided for by screening off a space between the great pillars of the nave or transept of some parish church or cathedral, and erecting an altar there. but frequently an addition was made to and opening into the choir, or a detached building was erected for the purpose.
|Wakefield Chantry Chapel, see link here|
To erect a chantry the consent of the ordinary, which was given only when it was found that a fund sufficiently large for its building and maintenance had been set aside, had to be obtained; then the permission of the Crown to alienate lands in mortmain had to be secured; and then, to provide against the violation of the rights of the mother-church, the priest in whose parish the chantry was to be erected had to be consulted; finally, to give it a legal character, it had to be instituted by the civil authorities of the locality.
|The Vaughan Chantry Chapel in Westminster Cathedral, see here|