Historic Window Replacement

Historic building window replacement presents a variety of challenges. The replacement must balance the needs and expectations

of the building owner and building occupants with current code requirements, historic commission or other historic review board 

requirements, and the physical properties of different window systems, all while maintaining the historic building’s fabric,

character, and architectural integrity.

Primary considerations in historic window replacement include:

•Desired thermal and acoustic performance

•Façade integrity

•Condition of existing window openings

•Interior building conditions

•Historic review and approval requirements




Each design parameter affects the others. For example, historic requirements may mandate narrow sight lines to replicate 

original glazed wooden sashes. New insulating glass might impact the muntin profiles or change shadow or sight lines.

A custom finish that eliminates the need for repainting may require thermally separated aluminum framing with deep glazing 

pockets. Deteriorated building framing may require a custom window rather than an off-the-shelf product.

Knowledgeable glazing contractors who evaluate and replace historic windows fully understand repair techniques and the

available options for restoration, conservation, and replacement to meet all of a project’s parameters successfully 

and efficiently.

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