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INSULATION - CSI DIVISION 07TRADE - THERMAL INSULATION

SF batts, BF spray foam, R-value, vapor barrier - by the assembly.

PlanSwift counts wall SF and forgets the R-value math. BuildBid reads the wall sections and the energy-code call-outs together.

Insulation takeoff (CSI Section 07 21) is a surface-area-by-R-value problem. Wall batts ship in SF by stud cavity (16-inch or 24-inch on-center, accounting for stud area subtraction), at the R-value the energy code or finish schedule calls out (R-13, R-15, R-19, R-21, R-23 in 2x4 / 2x6 / 2x8 cavity). Ceiling and attic insulation ships in SF at attic R-value (R-30, R-38, R-49, R-60 typical). Below-grade foundation insulation ships in SF rigid (extruded polystyrene XPS or polyisocyanurate) at code-required R-value. BuildBid reads the wall sections, the finish schedule, the roof spec, and the energy-code commentary together so each assembly is tagged with its R-value and the SF math is correct.

Spray foam is its own line. Open-cell at ~0.5 lb/CF density (R-3.5/inch) and closed-cell at ~2 lb/CF density (R-6/inch) are priced by board-feet (BF = 1 SF at 1 inch thickness). The energy code minimum dictates inches; the SF times inches calculation must use the SPRAY thickness, not the cavity depth. Closed-cell doubles as vapor barrier and air-seal so other line items drop when it's specified.

Vapor barriers + air sealing surface separately. Polyethylene vapor barrier SF (continuous interior side), housewrap SF (continuous exterior side under siding), self-adhering air-barrier membrane SF at joints/penetrations, caulking + foam sealant LF at framing transitions. The energy code's air-leakage requirement (ACH 50 < 3.0 typical) drives whether these are required.

Perimeter + below-grade insulation surfaces as their own assembly. Foundation wall rigid SF + thickness, slab-edge rigid LF + height, sub-slab rigid SF where called by the energy code (cold climates). Each has its own product and protection layer (protection board, parging, gravel backfill) per the spec.

Try on a sample insulation packageSee sample takeoff
WORKFLOW · HOW IT ACTUALLY RUNS5 STEPS
  1. STEP 01

    Upload wall sections + energy code data + finish schedule

    Wall sections (typical exterior wall, gable wall, roof / ceiling section), energy code commentary or ComCheck/REScheck output, finish schedule for insulation call-outs, foundation section. Specs 07 21 (thermal insulation), 07 26 (vapor retarders), 07 26 16 (below-grade vapor retarders), 07 27 (air barriers) cross-read for product, R-value, thickness, and continuity requirements.

  2. STEP 02

    Wall + ceiling SF by R-value

    Each wall section: wall SF (perimeter LF times height) minus framing area (typically 23% for 2x4 16in o.c., 21% for 2x6 24in o.c.) gives cavity-insulation SF. Tag each wall to its R-value from the energy commentary. Roof / ceiling SF from the roof plan, tagged to attic R-value (R-38 mixed-humid, R-49 cold, R-60 very-cold typical).

  3. STEP 03

    Spray foam by board-feet + density

    Each spray-foam zone: SF times spray thickness (inches) gives BF. Open-cell vs closed-cell determined by spec call-out. Closed-cell at vapor-barrier-replacement thickness (2-inch minimum typical) eliminates a separate vapor-barrier line. Open-cell typically full-cavity-fill — needs separate vapor retarder on interior side per code.

  4. STEP 04

    Vapor + air barriers SF + LF

    Polyethylene vapor barrier SF on interior side of cold-climate walls (or absent in warm-climate per code). Housewrap SF over exterior sheathing (continuous, lapped at edges). Self-adhering air-barrier membrane SF at all rough openings + sheathing-to-foundation transitions. Caulking + low-expansion foam LF at framing transitions.

  5. STEP 05

    Foundation + below-grade

    Foundation wall rigid SF (perimeter LF times below-grade depth) at code-required R-value (R-10 to R-20 cold-climate). Slab-edge rigid LF (perimeter times 24-in vertical typical). Sub-slab rigid SF where called (cold-climate basements). Protection board + dampproofing tied to the foundation section detail.

PAIN · WHAT THIS REPLACES

Where the hours actually go today

  • Wall SF priced at one R-value across the whole project when the finish schedule calls out different R-values by wall section (e.g., R-15 in 2x4, R-21 in 2x6, R-19+R-5 continuous in code-compliant assemblies).
  • Framing area not subtracted from cavity SF - estimates come in 20-25% high on cavity material because the studs aren't insulated.
  • Spray foam priced at SF rate instead of BF (SF times inches) - thin-coat application priced as full-cavity is wildly wrong.
  • Vapor barrier added on TOP of closed-cell spray foam (which already IS a vapor barrier) - double-counts material and creates a moisture-trap risk.
  • Foundation insulation missed because it lives on a separate section sheet - 30-50% of basement-condition-failure claims trace to skipped or under-specified below-grade insulation.
LIMITS · WHAT BUILDBID IS NOT YET

Honest gaps — read before you buy

  • Energy modeling (ComCheck / REScheck / Title 24 / Manual J): BuildBid extracts the R-value call-outs but does NOT run the energy compliance calculation - that comes from the energy modeler / mechanical engineer.
  • Acoustic insulation (CSI 07 92 19 acoustical joint sealants, 07 21 16 sound-attenuation batts in interior partitions): in scope when called by finish schedule, but acoustic-rating compliance (STC, NRC) is design-team specified, not parameterized here.
  • Spray foam contractor licensing + insurance: BuildBid quantifies the BF, but spray-foam-installer surety and applicator certification are vendor-side requirements not reflected in the takeoff.
  • Phase-change materials + reflective barriers: out of scope for the standard 07 21 baseline - flagged for separate research if specified.
REVIEW FOCUS · WHAT TO CHECK4 AREAS
CHECK 01

Cavity SF view: each wall section tagged to R-value + cavity depth + framing-area subtraction so material gallons / batts count is auditable.

CHECK 02

Spray foam zones: SF times inches gives BF by density (open-cell vs closed-cell), with vapor-barrier-replacement annotation when 2+ inches closed-cell.

CHECK 03

Vapor + air barriers: polyethylene SF interior, housewrap SF exterior, self-adhering membrane SF at rough openings + transitions.

CHECK 04

Foundation + below-grade: rigid SF on wall + slab-edge + sub-slab tied to the foundation section detail with R-value per energy code.

NEXT · TRY ON A SAMPLE

Sample plans, zero setup. The draft comes back with quantities, confidence flags, and the source rows we used. You review before you send.

Try on a sample insulation package