Share What You Know: How to Talk with an Architect about Glass EPDs

By Helen Sanders

As the need to reduce carbon emissions becomes more acute, design teams are focusing more on reducing embodied carbon in the materials used in constructing their buildings. This is resulting in requests from architects for environmental product declarations (EPDs) for glass and glazing products. My December blog argued that EPDs for flat glass and insulating glass to inform decisions relative to glass supply is largely irrelevant to reducing embodied carbon in buildings.

The key reasons are:
• Insulating glass contributes approximately 2% of the embodied carbon of a building’s core and shell;
• The insulating glass unit (IGU) manufacturing process only contributes to approximately 10% of those carbon emissions (0.2%); and
• While the flat glass process accounts for 75% of these emissions (1.5%), the current flat glass EPDs suggest that the emissions are the same, irrespective of supplier, within the typical margin of error.

Share Some Advice

So how should glass and glazing professionals advise architects on minimizing carbon impacts when designing with glass? First, explain why EPDs from different fabricators should not be used to make supplier selections. Design decisions related to IGU configuration, amount of glass and service life have more implications for reducing embodied carbon than choosing the supplier based on EPD data.

Instead, the data suggests following these design guidelines:

Locally source aluminum: Source aluminum from North American providers with low-carbon intensive electricity supply, and be efficient with its use.

Focus on IGU durability and service life: Specify an IGU design and suppliers that will deliver the best quality and in-service durability. Avoiding a “lowest bidder wins” approach allows fabricators to invest in higher quality materials and production.

Assess the lifecycle value of triple pane versus double pane: Does the operational emissions benefit outweigh the embodied carbon impact? How many years before the operational energy savings offset the added embodied carbon? Can the needed thermal performance be reached with a dual-pane unit, warm-edge spacer and a high-performance thermally broken frame? Can a triple’s impact be lowered with a thinner middle lite?

Design with efficiency in mind: Help fabricators reduce waste and improve efficiencies by, for example, reducing the number of unique sizes.

Find alternative lower cost ways to allow your fabricators to demonstrate their commitment to reducing the environmental impact of their operations.

Helen Sanders is in strategic business development for Technoform North America Inc. based in Twinsburg, Ohio. Read her blog each month at

To view the laid-in version of this article in our digital edition, CLICK HERE.