Published Planning Baseline
| NumeralQ scope | Planning baseline | What it covers |
|---|---|---|
| Blown-in fiberglass or cellulose attic insulation | View current estimate | Defined 1,500 sq ft attic scope, R-19 to R-38, including air sealing. |
This first-party planning baseline does not price batt, spray foam, or other insulation assemblies. See the estimate methodology for scope and limitations.
Insulation and Air Control
Insulation materials and air-control layers have different functions. Batt or blown-in insulation does not, by itself, seal every gap or penetration in a building assembly; air-sealing work may need to be specified separately.
Insulation, air control, and vapor control are separate functions that interact within a building assembly. Products vary, and installation details matter; do not assume a material alone will correct air leakage or moisture issues.
Practical implication: Have the assembly and air leakage assessed before choosing a product. A qualified energy professional can help identify whether air sealing, insulation, or another repair should be addressed first.
Where Each Type Performs Best
Batt Fiberglass or Mineral Wool
- Common applications: Open framing and accessible cavities where the selected product can be installed according to its instructions.
- Installation: Fit, compression, gaps, and moisture conditions affect performance; follow the product guidance and assembly design.
- Cost comparison: This guide does not retain a verified batt price baseline.
Blown-In (Fiberglass or Cellulose)
- Common applications: Attic floors and some existing cavities when compatible with the assembly and installation method.
- Product differences: Fiber, density, settling behavior, fire treatment, and moisture response vary by product; check its documentation.
Closed-Cell Spray Foam
- Selection: Spray-foam products may be considered for specific assemblies; verify compatibility, required protection, and installation details for the building and product.
- Design and installation: Confirm product specifications, thickness, fire protection, vapor-control properties, and assembly compatibility with the installer and applicable code.
- Cost comparison: This guide does not retain a verified material-by-material price comparison.
Open-Cell Spray Foam
- Selection: Review the product's tested properties and suitability for the assembly; vapor permeance and moisture-control requirements are design-specific.
Climate, Code, and Assembly
Insulation requirements depend on jurisdiction, building type, the existing assembly, and the work being performed. Check the applicable energy code and local permit requirements; do not treat a broad climate-zone recommendation as a project specification. Moisture-control design should be reviewed for the whole assembly.
Frequently Asked Questions
Is spray foam worth the extra cost over batt?
There is no supported universal price comparison here. NumeralQ's published baseline applies only to a defined blown-in attic scope. For another assembly, compare written bids with the same materials, thickness, air-sealing work, and exclusions.
How much insulation does my home need?
Requirements depend on the assembly, building type, and applicable local energy code. Check the jurisdiction's current requirements and have the existing conditions assessed before selecting a target.
What is the current federal tax-credit status for insulation?
The federal Section 25C credit is unavailable for property placed in service after December 31, 2025. State and utility incentives are separate and may have their own requirements; check current programs with each provider. Read IRS guidance.