Definition
R-value is a numerical rating measuring thermal insulation resistance. Higher values indicate better insulation performance. Different climate zones require different minimum R-values per code.
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R-value is calculated based on insulation material type and thickness. Different climate zones require different minimum R-values per code. Common residential R-values include R-13 (exterior walls), R-19 to R-30 (ceilings), and R-10 (basement walls). R-value requirements vary by building code jurisdiction and climate zone. Higher R-values improve comfort and energy efficiency but increase material cost. Insulation type (fiberglass, cellulose, spray foam) affects R-value per inch.
Pro Tip
Invest in insulation beyond code minimums. Additional R-value provides comfort and energy savings that pay back over time.
Example
A home in a cold climate includes R-30 attic insulation, R-21 wall insulation, and R-10 basement wall insulation to meet local code requirements.