Restoration Register

Heritage window restoration in Toronto and the GTA

An original double-hung sash window that is drafty is not a window at the end of its life. It is a window with failed putty, dried-out weatherstripping and a broken sash cord, which are three repairs that cost a fraction of replacement and keep glass that is often more than a century old.

Sash restoration work in the GTA covers the same short list on almost every house: reglazing with linseed oil putty, replacing broken cords and rebalancing the weights, consolidating rotted sills and rails with epoxy rather than replacing whole sashes, freeing painted-shut meeting rails, and fitting discreet weatherstripping. Where original cylinder or wavy glass survives, a restorer keeps it, because modern float glass is flat and dead and no replacement window sold in Ontario reproduces it. On energy, a restored sash with good weatherstripping and an interior or exterior storm performs close to a modern sealed unit, at a fraction of the embodied carbon and without the twenty-year replacement cycle.

What to ask before you hire

  1. Will you repair the existing sashes or build new ones? Ask for a repair-first quote. Rebuilt sashes are sometimes right, but should be the fallback, not the opening position.
  2. How will you handle the original glass? Wavy and cylinder glass is irreplaceable, and a careful restorer prices around saving it.
  3. What are you proposing for weather performance: storms, weatherstripping, or both? That is where the comfort gain actually comes from, not from the glass itself.
Grant funding

Window restoration is eligible under most GTA programs, including Toronto's at 50% to $10,000 on residential designated property. Several municipalities will fund restoration but not replacement, which is another reason to get the repair quote first.

Contractors on this page

Part of

All heritage service pages · Grants by municipality