{
  "slug": "attic-blown-in-insulation-cost",
  "title": "Attic Blown-In Insulation Cost Calculator",
  "heading": "Attic Blown-In Insulation Cost Calculator",
  "category": "financial",
  "url": "https://www.revenuelab.fyi/toolbox/attic-blown-in-insulation-cost",
  "summary": "Coverage area, target R-value, and material type for a blown-in attic insulation job.",
  "description": "Blown-in attic insulation cost is driven by attic square footage, target R-value (which determines how many inches deep the material needs to be blown), and material choice between cellulose and fiberglass, which price differently per bag and per square foot at a given depth. This calculator prices the job using a per-square-foot rate that already reflects the depth needed to hit your target R-value, then adds an allowance for baffle installation (needed at eave vents to maintain airflow) and existing insulation removal if the attic has old, contaminated, or wet insulation that needs to come out first. 2026 US national averages run about $1.50-$2.50 per square foot for a standard fiberglass blow-in to R-38 (roughly 12-14 inches), and $1.75-$3.00 per square foot for cellulose, which is denser and offers slightly better sound dampening and fire resistance. Removing old insulation first typically adds $1-$2 per square foot. Most of the US falls into recommended attic insulation levels of R-38 to R-60 depending on climate zone — colder northern climates should target the higher end of that range.",
  "formula": "Total = (Sq Ft × Rate per Target R-Value) + Baffle Installation + Old Insulation Removal (if needed).",
  "dateModified": "2026-09-06",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=attic-blown-in-insulation-cost",
  "inputs": [
    {
      "id": "sqft",
      "label": "Attic floor area",
      "kind": "number",
      "hint": null,
      "default": 1200,
      "unit": "sq ft",
      "min": 200,
      "max": 6000
    },
    {
      "id": "targetR",
      "label": "Target R-value & material",
      "kind": "select",
      "hint": null,
      "default": "2",
      "options": [
        {
          "value": "1.6",
          "label": "Fiberglass to R-38 — $1.60/sq ft"
        },
        {
          "value": "2.2",
          "label": "Fiberglass to R-60 — $2.20/sq ft"
        },
        {
          "value": "2",
          "label": "Cellulose to R-38 — $2.00/sq ft"
        },
        {
          "value": "2.6",
          "label": "Cellulose to R-60 — $2.60/sq ft"
        }
      ]
    },
    {
      "id": "baffleCost",
      "label": "Eave baffle installation",
      "kind": "number",
      "hint": null,
      "default": 300,
      "unit": "$",
      "min": 0,
      "max": 1200
    },
    {
      "id": "removalNeeded",
      "label": "Remove old insulation first?",
      "kind": "select",
      "hint": null,
      "default": "0",
      "options": [
        {
          "value": "0",
          "label": "No — blowing over existing"
        },
        {
          "value": "1",
          "label": "Yes — remove old first"
        }
      ]
    },
    {
      "id": "removalRate",
      "label": "Removal rate",
      "kind": "number",
      "hint": null,
      "default": 1.5,
      "unit": "$/sq ft",
      "min": 0.5,
      "max": 3
    }
  ],
  "outputs": [
    {
      "id": "totalCost",
      "label": "Total insulation cost",
      "format": "currency",
      "hint": null,
      "primary": true
    },
    {
      "id": "insulationCost",
      "label": "Blown-in insulation material + labor",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "removalCost",
      "label": "Old insulation removal",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "perSqft",
      "label": "All-in cost per sq ft",
      "format": "currency",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Attic floor area: 1200 sq ft",
      "Target R-value & material: Cellulose to R-38 — $2.00/sq ft",
      "Eave baffle installation: 300 $",
      "Remove old insulation first?: No — blowing over existing",
      "Removal rate: 1.5 $/sq ft"
    ],
    "outputs": [
      "Total insulation cost: $2,700",
      "Blown-in insulation material + labor: $2,400",
      "Old insulation removal: $0",
      "All-in cost per sq ft: $2.25"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter attic floor area (sq ft).",
      "Enter target r-value & material.",
      "Enter eave baffle installation ($).",
      "Enter remove old insulation first?.",
      "Enter removal rate ($/sq ft).",
      "Read your total insulation cost on the right — it updates as you type.",
      "Hit Share to keep the scenario or send it to someone."
    ]
  },
  "scenarios": [
    {
      "name": "Conservative",
      "description": "Lower-end numbers — what if things land soft?",
      "values": {
        "sqft": 700,
        "targetR": "2",
        "baffleCost": 200,
        "removalNeeded": "0",
        "removalRate": 0.8999999999999999
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "sqft": 1200,
        "targetR": "2",
        "baffleCost": 300,
        "removalNeeded": "0",
        "removalRate": 1.5
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "sqft": 1900,
        "targetR": "2",
        "baffleCost": 500,
        "removalNeeded": "0",
        "removalRate": 2.4000000000000004
      }
    }
  ],
  "limitations": [
    "Results are estimates before tax, fees, and inflation unless an input explicitly covers them.",
    "Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.",
    "This is educational maths, not financial advice. Check anything contractual with the lender or your accountant."
  ],
  "faq": [
    {
      "q": "Cellulose or fiberglass — which is better for attics?",
      "a": "Both perform similarly for thermal resistance at the same R-value; cellulose is denser and settles slightly less over time with better sound dampening and fire-retardant treatment, while fiberglass is lighter, doesn't absorb moisture as readily, and is usually a bit cheaper per square foot."
    },
    {
      "q": "Do I need to remove old insulation before blowing in new insulation?",
      "a": "Not usually — new insulation can typically be blown directly over old fiberglass batts or loose-fill as long as it's dry and not contaminated with mold, pest droppings, or vermiculite (which may contain asbestos and requires special abatement removal instead)."
    },
    {
      "q": "What are baffles and why do they matter?",
      "a": "Baffles are rigid channels installed at the eaves before blowing insulation that keep loose-fill material from blocking soffit vents, preserving the airflow path that ventilates the attic and prevents moisture buildup and ice dams — skipping them is a common and costly mistake."
    },
    {
      "q": "How much can attic insulation save on energy bills?",
      "a": "The US Department of Energy estimates homeowners can save 10-15% on heating and cooling costs by properly insulating an under-insulated attic, with payback periods commonly in the 2-5 year range depending on local energy costs and climate."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/ice-dam-removal-cost",
    "https://www.revenuelab.fyi/toolbox/ridge-vent-installation-cost",
    "https://www.revenuelab.fyi/toolbox/attic-fan-installation-cost"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Attic Blown-In Insulation Cost Calculator (https://www.revenuelab.fyi/toolbox/attic-blown-in-insulation-cost)"
}