by Michael J. Crosbie, PhD
Contributing Editor

Summary: Some new research in Great Britain points to how older houses, with their greater girth and heavy materials, might be better energy-savers than their younger counterparts. There are fixes, too, that may help: A lot of them center on replacing glass and new glass technologies.

Last month, reports from England delivered some staggering news about building performance. According to the U.K.’s Guardian newspaper, recent tests conducted for British Gas revealed that Tudor houses built in the 1500s performed better in terms of envelope tightness than their mock Tudor knock-offs constructed in the 1960s. Burly in construction, the 500-year-old abodes leaked 10 cubic meters of air an hour for every square meter of wall, compared to 15.1 cubic meters for mock-Tudor homes of the ‘60s.

Traditionalists were jubilant with the news

Homes built during the 1970s performed slightly better—they lost 11.7 cubic meters—but they couldn’t beat those heavy-timbered structures and their wattle-and-daub infill walls. Traditionalists were jubilant with the news. “Wind turbines, solar panels, and other high-tech green devices might get the media attention,” said Hank Dittmar, chief executive of Prince Charles’ Foundation for the Built Environment, “but the smartest way to save energy might be to live in a Tudor house and insulate the attic and repair the windows.”

They don’t make ‘em like they used to
Well, living in a Tudor house isn’t a realistic choice for most, but the findings bring up a couple of issues about green design and construction that are worth considering. First, many older buildings potentially can be better energy performers than those more recently constructed. Structures built before World War II are often very substantial. They might not have insulation, and their windows might be a little drafty, but their shortcomings can be overcome by adding insulation and upgrading the windows. In most cases, these buildings are far better energy performers than those constructed just after the war, up through the 1960s and ’70s. These “boomer buildings” are notorious under-performers in terms of thermal comfort and energy consumption. Their hapless owners are now faced with a difficult decision: Should they work with an architect and upgrade them, or is it wiser to just tear them down altogether?

Energy was cheap; girth was great
What happened in the second half of the 20th century? Post-war buildings were constructed in the wake of low-cost oil and electricity and the promise of “too cheap to meter” nuclear energy, resulting in far fewer demands for good energy performance. You could always boost the heat or crank up that air conditioning. Also, the International Style did not help. Thin wall sections and acres of single-pane glass in un-insulated frames were a recipe for dismal thermal performance. Buildings designed in traditional, classical architectural styles were likely to perform better through their sheer material girth.

The International Style’s thin wall sections and acres of single-pane glass in un-insulated frames were a recipe for dismal thermal performance

Other factors contributed to the post-war building’s poor environmental performance. Building booms usually encourage poor construction practices. High demand and the need for speed invite corners to be cut, and those corners are usually cut in places no one will see—such as insulation levels, caulking, thermal barriers. Quick construction also results in a decline in building craft and skill, which adds to sub-par environmental performance.

The answer is clear as glass
Ironically, many of today’s architects are dealing with the sins of their fathers (and mothers). They are being called upon by clients to rectify the miserable environmental performance of post-war buildings, which are literally falling apart. One of the biggest problems in such buildings is glazing failure. In cold climates, multi-pane glazing in insulated, “thermally broken” frames can be substituted for those that suffer from “thermal bridging” (where cold temperatures are directly transferred inside through solid steel or aluminum window frames). Glass coatings now offer better performance than ever in reducing solar gains in hot climates, keeping interiors cooler to reduce the load on air-conditioning equipment (sometimes such high-performance glazing can result in lower AC tonnage). New glazing technology and other sustainable strategies mean that you can make even a Modern building from the post-war years more sustainable—maybe even better than a 500-year-old Tudor.