Heritage Windows

Yes, heritage windows do require maintenance. Activities such as paint spot maintenance, repainting, or touching up glazing putty need to be done on a regular, cyclical basis. 

• Heritage windows are maintainable. Almost anything that goes wrong with them can be repaired. 
• Products advertised as “Maintenance-free” are often un-maintainable and become disposable. For example: broken proprietary hardware may no longer be available, the seals in a modern insulated glass often fail and sometimes require that the entire sash be replaced and the colour of vinyl or aluminum cladding eventually fades.
• Heritage materials such as lumber cut from old growth virgin forests which have a superior stability and weather resistant properties, will often outlast replacement materials. 
• The fact that so many heritage buildings still have their original windows 150 years later is a testament to the quality of the material and construction.

Repairing and upgrading existing windows, instead of replacing them, has environmental, social and economic benefits:

• Increase the monetary value of the house
• Save energy and money over the long run
• Conserve the heritage value of the house
• Add to the value of the neighbourhood

When people talk about energy efficiency in the context of windows, they are typically concerned about cold air blowing in, cold drafts off the surface of the glass and condensation resistance. With the use of quality weather stripping, on operating joints, the use of sealants on fixed joints and repairs to broken glass and glazing putty, drafts can be controlled. With the addition of another piece of glass, such as traditional storm window or a storm panel on the interior, condensation can be controlled. 

Heritage windows can be upgraded to acceptable standards, comparable to most modern windows.  

A program of window repair and upgrade is often cheaper than total replacement.

It is important to look at the life cycle cost analysis of repair vs. replacement over 20 years; factoring in the capital cost, the thermal upgrade, maintenance costs and energy savings as well as the lifetime of that product.

The repair of existing heritage windows can’t always be compared directly to the replacement of windows. 

Many modern replacement windows will show signs of failure within 10 years and require total replacement in 15 to 20 years. 

More energy and time will be spent replacing a modern window that maintaining an existing heritage window.

Restoring and repairing existing windows is the environmentally responsible choice.  It conserves the materials used in the original windows and avoids the unnecessary fabrication and transportation of new materials. It also means that repairable windows aren’t sent to landfills.

Wood windows are usually made from old – growth wood, which is more durable and stable than wood today. The hardware used in older windows also tends to be sturdier that it’s modern counterpart, and can stand up to repair and restoration work. 

Repairing and restoring existing windows – instead of replacing the windows manufactured in some other location – supports local workers and craftsman.  Work that is done locally also helps local contractors learn restoration skills. 

It is better to reuse existing materials. The processing of materials such as aluminum and vinyl has harmful effects on the environment. 

The replacement of original windows in heritage buildings is only justifiable typically for these reasons:

• windows have previously been replaced with units that detract from the heritage character of the building
• windows are so severely deteriorated that, even if they were repaired, very little original fabric would remain

If window replacement is justifiable (i.e. sometimes on less significant facades such as the rear), what should be considered?

• They should be custom made to replace the originals.
• Unique features such as material, moulding profiles, muntin bar sizes and the joinery should be matched precisely. 

Learn as much as you can about your heritage windows:

• Contact a City of Hamilton Cultural Heritage Planner at CulturalHeritagePlanning@hamilton.ca
• The Standards and Guidelines for the Conservation of Historic Places in Canada
• Window Preservation Standards
• Barriers to the Conservation of Pre-World War II Residential Wood Windows

Making the right choice

• Step 1. Contact an expert such as a heritage consultant or window expert. Beware of the sales person. 
• Step 2. Assess the existing condition of your heritage windows.
• Step 3. Assess the problems such as air or water leakage, condensation build-up or aesthetics.
• Step 4. Assess the solution since sometimes it’s as easy as applying a bead of caulking.