This chapel was a substantial structure as the remains of stone pillars from the building to be seen in the garden suggest. The Hospital itself eventually assumed a shape typical of this period, a H with the Great Hall forming the crossing point between two wings, which still exist today.

Most of the building dates from the late fifteenth century and is of timber framed construction. Much of this timber frame would have been cut to size and fitted together in the timber yard before being dismantled and re-erected on site, making timber framed buildings amongst the first "pre-fabs". So that each piece was put together in the right order, the timbers were marked by the carpenters. These marks can be seen throughout the building usually in the form of roman numerals. The spaces between the beams were in-filled with wattle and daub. The wattle, a woven construction of wood was covered by the daub, a plaster whose ingredients could include mud, lime, cow dung, horse hair or straw.