This past Thursday I attended a lecture by architect Matthew Bronski about the year in Italy he spent studying the architecture of that country. He wanted to see why some ancient buildings have survived to this day while others failed miserably.
One of his conclusions was that there is a "Darwinian" evolution in architecture. That is, through a long process of trial and error, builders and designers learned what worked and what didn't. They learned, for example, that large roof overhangs protected the wall below by keeping a lot of the water away. Cathedral builders started with modest, tried and true arches as used in Roman aqueducts and gradually learned that these arches could go higher and lighter than they ever would have thought. Sometimes the builders were too ambitious and their cathedrals collapsed while under construction, but even through these failures they learned important lessons.
As this knowledge was passed on from one generation of designers and builders to the next, the architectural language may have evolved but the underlying lessons such as how to shed water from a window opening were still relevant. Follow these guidelines and your building would last. Veer away from them and it's anyone's guess as to the outcome.
This theme came up again at the "Green" symposium that I mentioned in the previous post. Charles Sullivan of the Cambridge Historical Commission made the exact same observation in the context of our own domestic historic architecture: the wise designer and builder studied and learned from those of previous generations. Even as styles change, the basic principles of protecting buildings from the elements remain fairly constant (although, of course, the materials change with time. I have seen 18th century windows flashed with strips of birch bark. Today we usually use metal flashing for this purpose).
These observations reminded me of a story I once heard about Walter Gropius, one of the fathers of modern architecture. Gropius was not interested in learning from previous generations. The story is that when he came to Harvard's Graduate School of Design he had his staff throw out all the models that Harvard had of the world's great buildings. He was creating something knew, he seems to have reasoned, and therefore the past had little to teach him.
So it is of no surprise that while Gropius was pushing the boundaries of architectural design, his buildings failed miserably at one of the principle measures of architecture: handling the elements. Instead of studying the details of the architecture that came before him, he invented new details. For hundreds of years, New England homes had steeply pitched roofs covered with overlapping shingles. This system handled the snow and rain admirably. Gropius used flat roofs. And they leaked. Almost immediately.
Indeed the entire realm of "modern architecture" is replete with examples of building envelope failure. A notorious example is I.M.Pei's addition to the National Gallery. Pei developed a new system for hanging the stone panels that make up the facade, instead of relying on proven techniques. His system did not allow enough room for expansion of the panels and they started crumbling. As a result, the entire facade had to be removed and replaced at a cost of about $85 million. Talk about non-sustainable design!
In my eye, this is the same hubris that was the fatal flaw of the designers of the Titanic. In the residential field, we have seen many new systems and methods fail miserably because their promoters, too, failed to learn the important lessons taught by the architecture of preceding generations.
As a preservation contractor, I am constantly observing the 18th, 19th, and early 20th century buildings that I work on- and the new houses that are being built today. It's a sad fact that the carpenter who installed those strips of birch bark over the windows of that 18th century house had a more intuitive grasp of this importance of this type of detail than many of the new home builders today. Instead of a system of overlapping materials many of todays carpenters rely on things such as sticky tape to keep water out. Yes, that will keep water out for a while, but what happens when that tape fails?
That's why so many historic houses have lasted so much longer than the houses being built today. To me, if a building is not designed and built to last for a century or more, it is not sustainable no matter how much bamboo or CFL lightbulbs are used. So in my eye, the historic houses we work on and preserve for future generations are the very essence of sustainability.
My carpenters know that longevity of our work is of prime importance to me. We do not tolerate work that will not last, not just for the warranty period, but for many, many years beyond. To do this often requires advising our clients to invest in better materials, spanish cedar for exterior trim, for example, instead of inexpensive primed pine that will rot out in 5-10 years. But it also requires instilling an attitude in the field that speed is less important than getting the details right.
How about you? What do you think about the "sustainable" architecture of today?