Fabrica ecclesiae or fabrica ecclesiæ is a Roman Catholic Latin term, meaning, etymologically, the construction of a church, but in a broader sense the funds necessary for such construction.
This expression may also be used to designate the repairing and maintenance of churches, the daily expense of worship, and to the amount requisite for covering these expenses. In this particular connexion, the expression is first met with in the letter of Pope Simplicius to Gaudentius, Bishop of Aufina (19 November 475); however, even then it was not new, being borrowed from profane usage.
During the first Christian centuries the temporalities intended to meet the expenses incurred by the religious services carried on throughout a diocese belonged entirely to the cathedral church, and constituted a common fund which the bishop used, at his option, in defraying the expenses of religion, supporting his ministers and caring for the poor.
But in the fifth century, particularly in Italy, this common fund was divided into four parts, one of which was set aside for the fabrica ecclesiæ. In Sicily however, in 494, no portion was especially reserved for the fabric, and in Gaul such an allotment seems to have been unknown. In Spain, a third of the ecclesiastical revenues was assigned to the luminare (lights), a term synonymous with fabrica.
The increase of Christianity in the rural districts brought with it a change of discipline, according to which each church obtained a separate patrimony. In fact, benefactors no longer bestowed their gifts on the entire diocese, but on one particular church, frequently in honour of some saint specially venerated there. The common fund itself was divided among the churches of the diocese. Some writers maintain this division was owing to the establishment of ecclesiastical benefices; others claim that it followed the canonical recognition of the private ownership of churches.
After vainly endeavouring to restrict the exercise of public worship to churches whose ownership had been completely renounced by the founders, the canon law eventually permitted public worship in churches that remained the private property of an individual, a monastery or even the episcopal mensa, or estate. The owner was however obliged to set apart a special fund for the needs of the church (pro sertis tectis, or for the luminare). Henceforth, when a bishop established a new parish, he was bound to provide for its needs by a specified income to be deducted from the common diocesan estate or fund–of course, if no benefactor had otherwise endowed the parish. Some hold that in consequence of the principles governing feudal society all medieval churches and their revenues became private property, and that the conflict of Pope Gregory VII and his successors against the Holy Roman Emperors concercing lay investitures was in reality an effort to restore its lost possessions to the ecclesiastical domain. The result of so much strife was the transformation of former proprietary rights into the Jus patronatus 'right of patronage'.