Significantly improves it. A typical attic + walls foam package moves a Columbus home from a HERS 100 (code-built) to HERS 60-70. Lower HERS = lower utilities = higher resale value.
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HERS (Home Energy Rating System) Index measures energy performance on a scale where 100 = code-minimum new construction, 0 = net-zero, and higher numbers = worse performance. A typical pre-1980 Columbus home rates HERS 130-160 unimproved. After attic-plus-rim-joist foam: HERS typically drops to 110-130. After full-home foam package (attic + walls + crawl + rim joist): HERS reaches 60-80. Each 10-point HERS improvement correlates roughly to a 10% reduction in annual energy use. HERS scores feature in real-estate listings increasingly often, especially in higher-end Columbus neighborhoods (Upper Arlington, New Albany, Dublin) where buyers compare energy performance. Energy-rater certification is a separate professional service ($300-$600 typical) that produces the formal HERS document; the foam closeout documentation lets a HERS rater complete the assessment efficiently. Columbus HERS-rating availability: certified HERS raters in Greater Columbus run $300-$600 for a full residential rating. The rating includes a blower-door test, duct-leakage test, and comprehensive envelope assessment. The resulting HERS Index is increasingly featured in real-estate listings, especially in higher-end Columbus neighborhoods. The rating is a separate professional service; the foam closeout documentation gives the rater everything needed to complete the assessment efficiently.