Landmarks Not Landfill: Prism Glass
by Lloyd Alter, Toronto 
on 05.30.08
I am at the 2008 Heritage Conservation conference in Collingwood, Ontario, where the theme is Landmarks Not Landfill: Heritage Preservation and Environmental Sustainability.
Romas Bubelis, architect for the Ontario Heritage Trust, did a presentation on how design and construction techniques from the 19th and early 20th century were naturally green, given that they didn't have much affordable artificial lighting or ventilation and had to develop zero-energy techiques. I almost fell out of my seat in the Gayety Theatre when he described prism glass, which I had seen on buildings for years but never understood the point.
Prism Glass was originally developed to channel light into the holds of coal-carrying ships, so that one could see in the holds without needing a candle or lantern, a wise move in such a space. Stanford White used it with great success in the floor of Penn Station, where light from the dramatic skylights above filtered through to the train tracks below the floor of the station. (last week's visit to the current Penn Station followed by a viewing of this picture brought home what an architectural crime the loss of this building was)
The 19th century version of Architectural Graphics Standards would say with an 11 foot ceiling, light would penetrate 24 feet. But In 1897 the Luxfer Company introduced the Luxfer Prism glass, made at a wide range of different angles for different latitudes and purposes, that would bring natural light deep into stores and offices. Now buildings could be deeper, stores could be brighter, and buildings sprouted bands of translucent panels of small panes above their picture windows. And I thought it was just to cut down glare.
Of course, when electric lighting became affordable it was much more consistent and controllable and Luxfer prisms were no longer considered au courant. Yet the idea has returned in solar tubes and fibre optic systems and other expensive systems that are far more sophisticated than a fresnel lens mounted in a transom window.
I have a lot to learn this weekend. Read more on Prism Glass
Follow @TreeHugger on Twitter & get our headlines with @TH_rss!
Thirsty for more? Check out these related articles:
- How to Convince Your Family Contracting Business to Go Green
- Runners: Choose a Marathon that Matches Your Eco-Values
- Meet Change Maker Christopher Raeburn of Raeburn Design
- Steve Thomas Goes on Tour, Talks About Woodworking and Father's Day
- Your Idle Computer Can Save Lives
- Holter Visits the Homestead National Monument of America, Thinks Your Should Too
I'm looking at the 11" x 8.5" plastic Fresnel lens on my desk, and I'm getting an idea. Wouldn't it be easy to make a plastic lens overlay for the top pane of a window to direct the harsh light of the sun up at the ceiling? I bet I could make one of these.
This is the smartest thing piece I have read on the intersection of Heritage and climate change. I have often said that the thing we need most from the past is not old buildings, but rather, old patterns of living.
That being said, the landmarks not landfills canard is a stupid false choice and conservers need to get over it. There are many profitable businesses that deconstruct buildings so the materials can be re-used. The quality materials found in old buildings can be used in many fine new buildings, which emulate the old patterns of passive lighting and natural ventilation, with the benefit of new technologies, energy modelling and understanding of passive design.
Let us be clear. Most old buildings merely slow the wind down. They are abysmally hard to heat, as any reading of period novels will tell you. I cannot support using energy to heat sentiment.
Fortunately, several projects have successfully showed net-zero building retrofits. Get on it, or tear the heap down.
"Landmarks not Landfills" is hardly a canard, and the idea of grave robbing to furnish new buildings with irreplaceable timber and masonry is abhorrent. I urge you to look at the body of knowledge on heritage buildings (ordinary ones, too, not just landmarks). For example, in North American, the Association for Preservation Technology www.apti.org has for 40years examined the philosophy and practice of keeping our existing building stock useful.