Peter Smithson in his seminal essay “A Parallel of the Orders,” argued that a construction system becomes an order and then evolves (or really devolves) into a decoration. He claims that this is the natural course of architectural development. He then argues that the first two steps are acceptable whereas the third is heretical:
The [Doric] Order is a form—metaphor of a once-actual structure...[William Bell] Dinsmoor uses the word ‘translation’ into stone of a wood and terracotta original, but this I suggest is an inadequate word to represent the process of change from a construction into an Order....A metaphor is an explaining, a magical exact showing-forth. It does not involve exaggeration or falsification.
On a recent walk I encountered three masonry window sills–a common construction detail– that encapsulate that thought. I call them: The Good, the Bad and the Ugly. (We are going to take Smithton's idea and reorder them slightly.)
The first is a limestone sill for a window opening in a nineteenth century loadbearing masonry wall. The sill is pushed past the brickwork an inch and a half and has an extruded quarter circle subtracted from its bottom. This subtraction is a drip. It keeps the water from wicking its back and then running down the wall. The work is beautiful and functional. The brick underneath is clean and gorgeous.
The second or the Bad is the detail as an ornament. The sill is now flush and no longer has a drip. The wall is two or three wythes thick and is still loadbearing but the mason has cut a vertical expansion joint into the masonry as one would for a evener brick wall which this is not. The value of a window sill is that it sheds water AWAY from the masonry below. Since the sill is now flush with the wall, it is a decorative device. It is masonry as wallpaper. Salt stains the brick as it now runs directly down the wall rather than being redirected like the first sill on the left. (This building houses a respected plumber and the work was beautifully executed by experienced union masons. The masons even kept the work covered and heated in inclement weather as is recommended. I was very impressed. The design, though, is problematic.)
The third, or the Ugly, sill detail is on a warehouse converted into a very groovy looking eating establishment around the corner from the office. The masons replaced a limestone sill in a loadbearing masonry wall. The new sill is extended like the Good one but lacks a drip. The bottom place is instead flush eliminating the proper pathway to shed water. The mason added a rope weep to the corner. The new mortar is a different color, has a different aggregate and is probably a different strength than the existing. Salts run down the edge between the sill and the masonry. The weep has no place here. It is a tool for airing out a cavity under a masonry veneer wall. This is a solid wall of masonry so either the mason does not understand the difference between the two or someone misdirected them.
What's the verdict? Architecture styles, fashions and practices may come and go but the laws of physics and gravity remain constant. An unsupervised, unlicensed mason–see the Ugly on the far right–is a dangerous thing. Also, a designer or architect who does not understand building science–see the Bad in the middle–is also a liability to your investment. Part of what we do at makeArchitecture is create new, beautiful and engaging expressions in masonry that create shadow, pattern and texture to delight. The other part is to make sure that detailing works and will wear and last as long it reasonably should. Old loadbearing masonry buildings have much to teach us yet.