Dave's Top Five Reasons to Conserve Historic Wood Windows

This is from the Architectural Conservation Notes series published by the Ontario Ministry of Culture. The notes aren't online at the moment (except through archive.org). I find that the heritage/preservation materials from other countries such as Canada and in Europe to be very good and resources that we need to draw upon.

Sadly, there aren't advertising campaigns and contractors calling up people and suggesting repair or the installation of interior storm windows, rather than wholesale replacement of "old" windows. Apparently most "new" windows fail after 15-20 years. But it doesn't really matter does it?, because the typical homeowner moves within 7 years.

Note #11:

Dave Taylor is an enthusiastic supporter of historic wood windows in heritage buildings.

When the original windows of the historic Fire Hall in Lindsay, Ontario were scheduled for replacement, Dave Taylor, architect Gordon Gilbert, and the Lindsay LACAC convinced residents that the original wood windows did not need to be discarded; they just needed repair.

After months of debate, the Lindsay Municipal Council decided to keep and repair the original wood framed windows, ensuring that an important landmark building in the downtown kept its distinctive character.

In their quest to keep the existing windows, Dave, Gordon and the Lindsay LACAC presented: Dave's Top Five Reasons to conserve historic wood windows.

REASON 5
Appearance/Architectural Significance

Some have compared the windows of a building to the eyes of a person's face. Clearly, the windows on traditional buildings are an important aspect of their architectural character. The size and proportion of the openings, the material that they are made from and their finishing details are all important in maintaining a building's character.

Taking a careful look at the windows will help you to see just how they contribute to the overall appearance of the façade. Look for any of the following features:

• The pattern of the openings and their size.
• The proportions of the frame and sash.
• The configuration of the window panes.
• Muntin profiles in making shadows and muntin proportions.
• Type of wood.
• Quality of light through the old glass.
• Paint colour or finish.
• Special details such as arches and shutters.

All of these characteristics play an important role in the appearance and heritage value of the building. We should keep in mind that when the architect designed the building, original window design played an important role in determining the desired look of the structure from the outside and from the room inside.

REASON 4
Durability

A common misconception concerning building materials is that because something is new, it is going to be better. This is not necessarily the case when modern windows are used to replace historic windows. The use of modern materials for windows has been a relatively recent development and their performance has not been measured over a long period of time. Historic wood windows have a proven track record.

Maintaining modern metal or vinyl clad windows can be expensive if problems develop. For example, windows with airtight sealed double panes can become faulty. The seals have a limited life span and when they fail, moist air entering the space between the panes can produce water droplets or cloudy films between panes. The solution is to replace the entire thermopane unit of glass, an expensive proposition.

Vinyl clad windows can deteriorate when moisture gets trapped between the vinyl and the wood. The rot can be so bad that, at times, the whole window has to be replaced.

In contrast, the best evidence of the lasting power of wooden windows is the fact that so many of them still exist on historic buildings. The quality of wood used at the turn of the century was superior to the wood used today. These windows have lasted for decades, some with maintenance, and others under conditions of total neglect. There is little doubt about the durability of historic wood windows.

REASON 3
Energy Conservation

The key to improving energy conservation of historic wood windows is to prevent air leakage. The thermal performance of wood windows can be improved with weatherstripping and sound putty work around the glass. In fact, according to Craig Sims, a heritage window expert, "Weatherstripping gives the biggest bang for the buck. [It] doesn't cost much and you can do a lot of windows in a day."

The traditional method of double glazing a historic wood window has been to add an exterior wood storm window. This improves the energy efficiency of the wood window and further assists in reducing condensation on the interior window surface during winter months.

REASON 2
Ease of Repair

All windows need regular maintenance and repair. Windows should be checked once a year for cracked or broken panes, intrusion of moisture, operation of the hardware and condition of the finish. In the past this was done when storm windows were being removed for the summer.

Wood windows will serve admirably if properly painted and adjusted over time. Window maintenance for wood windows is inexpensive (puttying, window stripping, painting), and if inspected annually, the costs will remain low over many years of service.

However, if parts of the window do deteriorate over time, there is still a way to save them. Traditional wood windows are made so that the frames, sash and muntins can be easily taken apart to replace a section that has deteriorated. For example, if a piece of muntin bar has deteriorated, it is possible to take that piece out and have another piece made to replace it. In this way components of the wood window can be replaced without throwing the entire window away. By comparison, when serious problems develop with modern windows, they are difficult to repair and usually result in replacement.

AND REASON 1
to Conserve Historic Windows is:
THEYSAVEMONEY!

With low cost maintenance, such as periodic painting and puttying, the original wood windows will last over 100 years. This is excellent return on a window that is already part of the building. There are almost no modern building materials on the market that can make that claim.

In terms of durability, historic character, energy conservation, ease of repair and

saving money, it makes good sense to maintain historic wood windows. Dave Taylor and the Lindsay LACAC saved the original windows on their historic fire hall, and they're glad they did.

For more specific information on improving your historic wood windows, please refer to:

1. Saving Historic Windows Makes Dollars and Sense, Craig Sims, Frontenac Historic Foundation, 1998.
2. Window Rehabilitation Guide For Historic Buildings, 1997, Historic Preservation Education Foundation.
3. Heritage Energy Conservation Guidelines, Ontario Ministry of Citizenship and Culture and Ontario Ministry of Energy, 1987.
4. The Repair of Historic Wooden Windows, Preservation Briefs #9, National Park Service.

For further information contact:

Heritage and Libraries Branch
Ministry of Citizenship, Culture and Recreation