Rules · Doors & windows · Ornament
Date a Gothic window by its tracery: openings pierced through a plate (twelfth century); geometric bar tracery of circles and foils (thirteenth); flowing curvilinear tracery of ogees and daggers (fourteenth); and, in England, perpendicular panel tracery with mullions running straight up into the arch (late fourteenth to sixteenth).
Thomas Rickman’s names (Early English, Decorated, Perpendicular) were coined in 1817 to classify English churches and are still used; the continental equivalents are Rayonnant (for the radiating tracery of the mid-thirteenth century) and Flamboyant (for the flame-like curvilinear forms of the fifteenth). Perpendicular, England’s own last Gothic, turns the window into a grid of panels and matches it with panelled walls and fan vaults.
Raise the central nave above the lean-to roofs of the aisles and pierce the upper walls with a row of windows, the clerestory, so that the middle of a wide hall is lit from high on both sides.
nave height ≈ 1½–2 × nave width; one window over each bay of the arcade
Load the top of a buttress pier with a heavy pinnacle: the added weight steepens the resultant of the flyer’s thrust and the pier’s own weight, keeping it well inside the base of the pier.
Draw a square the width of the pinnacle; inscribe a second square on the mid-points of its sides, and a third on the mid-points of the second. Turned back into line, the squares give the widths of the body, its panels and the spire; every height is a multiple of the first side.
widths: s, s⁄√2, s⁄2, s⁄(2√2) … · heights: n × s
Instead of cutting separate openings through a plate of wall, fill the whole window arch with glass and divide it by slender stone bars (mullions below, and circles, foils and sub-arches above) set out with compasses from the centres of the window’s own arches.
Design a rose by dividing the circle into equal sectors; fill each with the same traceried unit (a light with a cusped pointed head, an oculus above) radiating from a central hub, so that the whole is generated from one sector by rotation.
n petals · each sector 360° ⁄ n
Let the principal room of the front stand out in a bay window, canted or square, under its own gable: more light, a view along the street as well as across it, and a front that shows where the best room is.
Cite this page Chris Paton, “Plate, geometric, curvilinear, perpendicular”, The Textbook of Architecture, https://textbookofarchitecture.com/rule/tracery-sequence. Text, drawings and models licensed under CC BY-NC 4.0.