Passing a Quality Insulation Installation (QII) inspection on the first attempt can save builders time, money, and scheduling headaches. Corrections and reinspection can delay drywall and subsequent trades. This checklist covers the practical items builders should review before requesting rough-in field verification from an ECC rater (formerly HERS rater).

For 2025-code projects, the CEC’s Reference Residential Appendix RA3.5 defines the QII installation and rater-verification procedures. Use that procedure with the approved project details; this checklist is only a coordination aid.

Before Insulation Begins

Verify the CF-1R Compliance Documents

Before any insulation goes into the walls, confirm that you have current compliance documents for the home and that the insulation specifications match what your contractor plans to install. The ECC rater (formerly HERS rater) compares the field installation with the applicable documents, and a mismatch in R-value, insulation type, or installation method may require correction. If material substitutions are necessary, coordinate with your energy consultant before installation begins.

Communicate QII Requirements to Your Insulation Contractor

Not every insulation contractor is familiar with QII expectations. Before the project starts, review the approved assembly details with the crew: insulation should fill the intended cavity, remain aligned with the designated air barrier, and avoid gaps, voids, and avoidable compression.

Ensure Framing Is Ready for Insulation

Insulation quality depends heavily on framing quality. Before insulation begins, walk the house and verify that framing, blocking, backing, and air-boundary details are complete where required by the approved assembly. Pay special attention to kneewalls, cantilevers, tub or shower surrounds on exterior walls, and dropped soffits, where missing backing or an incomplete boundary can create correction items.

Coordinate with Other Trades

Coordinate plumbing, electrical, and HVAC rough-ins before insulation begins where the construction sequence allows. Later work in insulated cavities can displace or compress material and may create correction items, so plan a crew recheck whenever another trade returns to the thermal boundary.

During Insulation Installation

Full Cavity Fill — No Exceptions

Review the framing cavities and other insulated areas within the project’s thermal boundary for the coverage required by the approved assembly. Commonly missed locations can include:

Above windows and doors (header cavities)
Behind tubs and showers on exterior walls
Rim joists and band joists at floor transitions
Cavities around garage-to-living-space walls
Floor cavities over unconditioned crawl spaces or garages
Kneewalls in bonus rooms and attic spaces
Dropped ceiling soffits that intersect exterior walls

A missed in-scope cavity may require correction. Walk the house after insulation is installed and check the applicable areas on this list before calling for the QII inspection.

Proper Fitting Around Penetrations

Pipes, wires, ducts, and electrical boxes within an insulated cavity need the fitting required by the approved assembly and product instructions. Batt insulation can often be split around wires and pipes instead of compressed, while electrical boxes need a fitted cut that preserves the intended insulation thickness. Review the common QII failures and prevention guide with the crew before the self-inspection.

No Compression of Batts

Batt insulation must fill the cavity to its full intended thickness without being compressed. An R-21 batt designed for a 2x6 wall cavity should fill the full 5.5-inch depth. If a batt is too thick for the cavity, it must be replaced with the correct size — not compressed to fit. Similarly, batts should not be doubled over, folded, or bunched to fill oversized cavities. Each batt should be cut to the exact dimensions of the cavity it occupies.

Insulation in Full Contact With Air Barriers

Install insulation in alignment with the air barrier identified by the approved assembly and applicable QII criteria. In a typical framed wall using exterior sheathing and interior drywall as boundary surfaces, fit the insulation to avoid unintended gaps or misalignment; other assemblies can use different air-barrier locations and details.

In attic spaces, insulation must extend to the full depth over the top plates of exterior walls. Insulation baffles should be installed at the eaves to maintain ventilation channels while ensuring insulation extends to the outer edge of the wall below. In floor assemblies over unconditioned spaces, insulation must be in contact with the subfloor above and supported from below to prevent sagging.

Correct Depth and Density for Blown-In Insulation

If blown-in insulation is used in attics, walls, or floors, follow the approved plans and the product manufacturer’s coverage, depth, and density instructions. Use the documentation and markers required for the selected system so the installed R-value can be verified.

Before Calling for Inspection

Conduct Your Own Walk-Through

Before scheduling the QII inspection, conduct your own thorough walk-through of the house. Use a flashlight and check accessible wall, floor, ceiling, and attic areas. Look for gaps, voids, compression, missing insulation, and trade damage. Correct visible deficiencies before the ECC rater arrives.

Verify Access to All Areas

The ECC rater needs safe access to the areas included in the field verification. Keep attic and crawl-space entries clear and remove stored materials that block the insulation from view.

Ensure Proper Labeling and Documentation

Keep the product and installation records required for the selected system available, such as labels, coverage information, or installer certificates. This documentation helps the ECC rater compare the field installation with the current compliance documents.

After the Inspection

Address Corrections Promptly

If the ECC rater identifies deficiencies, address each documented item before requesting reinspection. Correction scope varies, so keep drywall and other concealing work coordinated with the verification status.

Learn From Each Inspection

Track the types of deficiencies found on each project and share the information with your insulation contractor. Over time, you will identify patterns — certain areas that are consistently problematic, certain crews that produce better results, or certain building designs that require extra attention. Use this data to continuously improve your QII pass rates.

Partner With Poppy Energy

Builders and superintendents can contact Poppy Energy to coordinate a QII inspection window, review project documentation, and keep the insulation-to-drywall handoff moving.

A Builder's Checklist for Passing QII Inspection on the First Try