{"uid":"cap_IjfIYnSCUa7I1EfCcNg3t","slug":"home-energy-calculators-insulation-r-value-u-factor-18883b96","name":"Home Energy Calculators – Insulation R-Value & U-Factor","description":"R-value and U-factor of a wall or roof assembly from layers and thickness, with a framing-fraction correction and heat flow.","url":"https://home-energy-calc.x402tookit.com/insulation-r-value?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":["layers"],"properties":{"cavity":{"type":"string","description":"Insulated cavity layer as material:inches or name:Rr (for example 'fiberglass batt:3.5'); with framing it is combined in parallel"},"layers":{"type":"string","description":"Lines material:inches or name:Rr separated by semicolons, for example 'drywall:0.5; cavity insulation:3.5r; sheathing:0.6r'. Materials: fiberglass batt, cellulose loose-fill, open-cell spray foam, closed-cell spray foam, eps board, xps board, polyiso board, softwood framing, drywall, plywood"},"deltaTF":{"type":"number","description":"Temperature difference in F, with areaSqFt"},"areaSqFt":{"type":"number","description":"Surface area in square feet, to get heat flow"},"includeAirFilms":{"type":"boolean","description":"true to add the interior and exterior air-film resistances (R-0.68 and R-0.17), default false"},"framingDepthInches":{"type":"number","description":"Depth of the framing member in inches (default 3.5 for a 2x4); used with cavity"},"framingFractionPercent":{"type":"number","description":"Share of the wall area that is framing, 5 to 40 (default 25, typical for 16-inch spacing)"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","properties":{"asOf":{"type":["null","string"]},"layers":{"type":["array","null"],"items":{"type":"object","properties":{"r":{"type":["null","number"]},"layer":{"type":["null","string"]},"source":{"type":["null","string"]},"thicknessInches":{"type":["null","number"]}}}},"source":{"type":["null","string"]},"totalR":{"type":["null","number"]},"uValue":{"type":["null","number"]},"framing":{"type":["null","object"],"properties":{"cavityR":{"type":["null","number"]},"framingR":{"type":["null","number"]},"framingFraction":{"type":["null","number"]},"lostToFramingPercent":{"type":["null","number"]},"effectiveCavityLayerR":{"type":["null","number"]}}},"reasons":{"type":["array","null"],"items":{"type":"string"}},"summary":{"type":["null","string"]},"verdict":{"type":["null","string"]},"degraded":{"type":["boolean","null"]},"disclaimer":{"type":["null","string"]},"notChecked":{"type":["array","null"],"items":{"type":"string"}},"heatFlowWatts":{"type":["null","number"]},"airFilmsIncluded":{"type":["boolean","null"]},"heatFlowBtuPerHour":{"type":["null","number"]},"nominalRIfNoFraming":{"type":["null","number"]}}}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.02","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.02/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_C5_HUSajWypzE9Rch45zf","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.02","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Calculates the total R-value and U-factor of a wall or roof assembly from material layers and thickness, with optional framing-fraction correction and heat flow computation.","exampleAgentPrompt":"Calculate the R-value and U-factor of a wall assembly made up of 0.5-inch drywall, 3.5-inch fiberglass batt cavity, and 0.6-inch sheathing, with a 25% framing fraction and 3.5-inch framing depth — include the air films in the result.","exampleUseCases":[{"title":"Check wall insulation before renovation","prompt":"I'm renovating my living room and want to know the total R-value and U-factor of the existing wall: half-inch drywall, 3.5-inch fiberglass batt, and half-inch plywood sheathing, with 16-inch stud spacing (about 25% framing fraction). Include air films please."},{"title":"Estimate heat loss through insulated ceiling","prompt":"My attic ceiling is 800 square feet. The assembly is 0.5-inch drywall plus 6 inches of cellulose loose-fill. It's 35°F outside and 70°F inside. Can you compute the R-value, U-factor, and total heat flow through that ceiling?"},{"title":"Compare closed-cell spray foam roof assembly","prompt":"What R-value and U-factor would I get from a roof assembly of 0.5-inch drywall, 3.5-inch closed-cell spray foam cavity, and 1-inch polyiso board? Use a 15% framing fraction and 3.5-inch framing depth, and add interior and exterior air films."}],"resultDescription":"Returns the total assembly R-value, U-factor, a breakdown of R-value per layer (with source and thickness), the framing-corrected effective R-value and U-factor when a cavity and framing fraction are provided, and optionally the heat flow in BTU/h when area and temperature difference are supplied.","failureModes":["Missing required 'layers' parameter returns a validation error","Unrecognized material name in layers string may return null R for that layer","framingFractionPercent outside the 5–40 range may produce unexpected results","Very thin or zero thickness values may yield near-zero layer R-values","Malformed layers string (wrong delimiter or format) may fail to parse any layers"],"whenToPreferThis":"Use this endpoint when you need to compute the thermal resistance (R-value) and conductance (U-factor) of a specific wall or roof assembly from its constituent material layers, especially when framing members are present and a parallel-path correction is needed. It is more appropriate than a generic heat-loss calculator when the goal is to evaluate or compare insulation assemblies layer by layer rather than estimate whole-building energy loads.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-30T00:34:27.453Z","isFirstParty":false,"canonicalSlug":"home-energy-calculators-insulation-r-value-u-factor-18883b96"}