[1] A drawing in the British Museum by his friend Jacob Van Campen shows him to be very short and hunch backed.

Saenredam was a contemporary of the painter-architects Jacob van Campen, Salomon de Bray, and Pieter Post.

These pictures were based on precise measurements of the building and meticulously rendered sketches, done on site, in pencil, pen, and chalk, after which washes were applied.

Saenredam's paintings frequently show medieval churches, usually Gothic, but sometimes late Romanesque, which had been stripped bare of their original decorations after the iconoclasm of the Protestant Reformation.

Although Utrecht was the centre of the remaining Catholic population of the mainly Calvinist United Provinces, all the old churches were retained by the Protestants.

According to the J. Paul Getty Trust "Saenredam’s church paintings...owe their poetry to his remarkable blend of fact and fiction.

He began by making site drawings of buildings that record measurements and detail with archaeological thoroughness."