Heritage window testing project

Can a restored heritage window work as well as a new vinyl one? GV is contributing to a fascinating project with Mohawk College: air testing a restored heritage window:

This is a research project by Shannon Kyles for Mohawk College Applied Research

The research project initialized by Shannon Kyles is aimed at determining the thermal efficiency and air infiltration of restored 19th century windows compared to new 21st century windows. The research will address this question: Is it true that restored wooden windows are less energy efficient than new ones?

In order to provide the most energy efficient building possible, John Deelstra, Mark Lucking and Brad MacDonald of Mohawk’s Building Reno department have worked with Shannon Kyles to construct a test building. Industry partners Roxul and Turkstra Lumber have helped to provide quality products. Green Venture will be providing the Blower Door Test.

For more information about the project, email shannon.kyles@mohawkcollege.ca

Current Canadian Building Code specifications do not allow for the installation of restored PreWar windows on new buildings. Current energy retrofit funding is for replacement of windows, not restoration of windows. A recent study surveying home owners in Stratford Ontario found that those who had replaced their pre-War windows had done so thinking that new windows were more energy efficient .1 Further, these home owners would have kept their original windows had they had proof that a restored window would be as energy efficient as a new window. A definitive test comparing restored 19th century windows and new 21st century windows might be able to identify whether old windows are, indeed, less energy efficient than new ones. If not, are they less efficient than all new windows that have passed the energy criteria? Or are they less efficient than only the top-of-the-line windows?


When doing air infiltration tests in older buildings, each building will be different and thus the results may vary. To provide a test that compares strictly the window performance, a test building, eight feet by twelve feet, was constructed with two restored Georgian windows and two new windows. The new windows are 1) a top-of-the-line wooden window and, 2) a regular quality vinyl window both purchased from Pollard Windows. The Georgian windows were taken from an 1820 duplex in Hamilton and restored by two separate restoration companies; Furlan Conservation and Paradigm Shift Customs. This is the first test done comparing restored windows and new windows on a new building.


The test will measure:

1. Air Infiltration

2. Thermal Efficiency


Other considerations including ease of opening, access to air circulation when wanted, sound transmission, and aesthetics will also be also gauged. Recent publications have focused on other areas of energy consumption such as the embodied energy inherent in an existing 200 year old window vs. the energy to remove it, make a new window and then replace it again every 20 years or so. A discussion of the best use of resources overall would be advantageous.


A summary of preliminary results will be part of the presentation. Should the test prove that new windows are more energy efficient than restored windows, then further research into carbon footprint and disposal of new windows needs to be done. Should the test prove that restored windows are as energy efficient as new windows, then changes in the Building Code and Energy Retrofit programs should be considered.

-Shannon Kyles

PowerPoint Presentation

Blower Door Test and Thermal Energy Test
10:00 am May 10 2017
Leaside Building, Mohawk College, Stoney Creek Campus
481 Barton St, Stoney Creek, ON L8E 2L7

For more information, contact: 905 627 5999

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