TL;DR
Solar heat gain coefficient is the fraction of solar radiation striking a window that passes through as heat, rated 0 to 1 on the NFRC label; lower numbers admit less heat. The IECC sets climate-zone maximums, around 0.25 in hot southern zones, while cold-climate designs may welcome higher values for free winter heat on south glass.
What it means
Solar heat gain coefficient is the fraction of solar radiation striking a window that passes through as heat, rated 0 to 1 on the NFRC label; lower numbers admit less heat. The IECC sets climate-zone maximums, around 0.25 in hot southern zones, while cold-climate designs may welcome higher values for free winter heat on south glass. Alongside U-factor it is one of the two numbers that determine how a replacement window performs, and low-E coatings are the main tool for tuning it.
Where it sits in the glossary
Solar heat gain coefficient is part of the Trade jargon group inside the ProFix Directory glossary. Browse every term in this category from the glossary index.
Why Ohio homeowners should know it
This is a term Ohio homeowners encounter when reading contractor quotes, hiring paperwork, or inspection reports. Understanding it well enough to ask one good follow-up question is usually all the protection a homeowner needs.
ProFix Directory keeps definitions short on the index page and saves the longer context — Ohio-specific rules, where the term comes from, and which ProFix tools touch it — for these per-term pages so the term is easy to cite and easy to share.
ProFix tools that touch this term
See also
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