The Case for Continuing Education
Residential architecture has an extraordinary history, and for me its history is very personal. I grew up in a mid-century modern house that featured a flat roof – in Michigan, of all places – smokestack style chimneys, a split-level entry, and a forty-five degree orientation on its meager lot. The house was stained charcoal grey (really, black) with white trim, making it an exceptional target for airborne eggs on Halloween. The house featured a near curtain wall of south-facing aluminum windows and given its orientation, was an early example of a passive-solar home, before passive solar design was popular. This extremely unusual house in an otherwise unremarkable Grand Rapids suburb had a tremendous influence on my youthful fascination with and love for architecture – if not for wood windows.
During high school, I spent a summer in Cambridge, MA, having enrolled in the Harvard University Graduate School of Design’s (GSD) Career Discovery program. The GSD is housed in Gund Hall, a modernist wedge-shaped building designed by Australian architect and GSD graduate Jon Andrews and opened 1972. To get from the studios to Harvard Square, we usually walked through Harvard Yard, home to some of the country’s oldest structures. Some of the wood windows in these structures probably date back to the seventeenth century. The old (lead) glass windows shimmer magically.
At UVA, we enjoyed the Lawn and the Rotunda, Jeffersonian architecture writ large, and we often visited and studied Monticello, arguably the first architect-designed American residence. Next time you have occasion to visit, please take special note of Jefferson’s triple-hung windows and the chain-driven simultaneous-closing French doors. These meticulously preserved examples of 200-year old wood windows and doors are simply remarkable. Soon after college, I remember visiting friends in Siasconsett on Nantucket. The family home was at the very eastern tip of the island, about as far easterly as you can be and still be in the United States, and the 200-year old wood ocean-facing windows were subjected to extreme salt and wind conditions. That summer, the sashes were brought down to the yard and we re-painted them. Perhaps with appropriate maintenance, they will last another hundred years.
Graduate school brought me to Columbia University, a campus designed by McKim Mead and White, and offering countless wood windows to study, even while enrolled in a school dominated by deconstructionism. Post-graduation, I joined the profession, and have had the opportunity to work on numerous Landmark properties, both in New York City and beyond. We’ve been fortunate enough to restore and/or replicate windows dating back 250 years.
I’ve spent half a lifetime studying, experiencing, and practicing architecture, and if I were to pick a subject to teach, one of my favorite would be wood windows, both their history and what to consider when specifying them for contemporary projects.
When we look at the evolution of double-hung windows, the earliest versions rode up and down in vertical wood channels. To keep a sash in it’s open position, one could either place a peg in a hole, or place a block of wood on the sill. Both options are low-tech, but very effective. The simplicity of design of early wood windows ensured durability due to the few moving parts to wear out.
The engineers of the next generation of wood double-hung windows sought a solution to keep windows in any open position. Ingeniously, designers affixed counterweights with chains and pulleys hidden within a vertical chaise at the side of the sashes. The concealed counterweights weigh the same as the sash, and the sash is balanced in any position. The system also delivered the benefit of making the sash feel weightless when opening. My family recently rented an apartment in a Landmarked property built in 2007. Within the apartment were three of the original oversized weight-and chain windows. After 111 years, these three windows operated more effortlessly than any of the aluminum replacement windows installed in the last twenty years.
Properly maintained, historic wood windows can last indefinitely. I’ve often used this experience and the above anecdotes to assertively lobby clients to install wood windows and sign up for the perpetual maintenance associated with painted wood windows. Further study – continuing education of a sort – has made me rethink this recommendation.
Modern wood windows are superbly engineered. Air infiltration is reduced to almost nothing. The sashes accommodate double and even triple glazing. Sound attenuation can be addressed, and UV transmittance can be reduced. Most importantly, sashes can be tilted in for cleaning. These modern benefits, added with multi-generational durability further the case for wood windows.
Yet, it turns out that manufactured modern wood windows differ materially from their ancestors in two important ways, their material and their engineering. To save costs, manufacturers have switched from old-growth dense hardwoods to lighter pine species. To reduce the variability caused by working with a natural product (wood), sashes and frames are machine-planed and finger-jointed, creating a precise product that can satisfy rigorous laboratory testing and can be warranteed by the manufacturer. Unfortunately, modern production techniques cannot make soft-wood hard. Problematically, pine also has a lot of sap and resin, making the material less appropriate for painting.
The second challenge facing the perpetuity of a modern wood window is it’s mechanism for raising and lowering the sash, and most importantly, for keeping the sash at its intended position. Whereas first generation windows ran up and down in simple channels (held in place by pegs), and second generation windows were of the weight-and-chain variety, modern windows run up and down on something called sash liners. These are concealed and inaccessible tracks, usually made of plastic. Instead of chains and counterbalances, the windows are held in position by leaf springs, which fatigue over time.
The (finger-jointed) pine materials and mechanics of modern window both work against the durability of currently manufactured products. While I’ve been telling my stories and recommending painted wood windows for years, I feel we’ve gotten a bit lucky in that clients have often opted for a more cost effective option, or in many cases, asked that we specify custom-fabricated historically accurate windows – either weight and chain, or reproductions of colonial era window – both of which types can last generations.
With some humility, I realize my nostalgic preference for historic windows has been tempered by (continuing) education. This same process of challenging what we think we know can and needs to be applied to almost every construction system and element.