Manual J for permits: what reviewers actually want

The rejection email usually says something like: “Provide ACCA Manual J load calculations for the proposed equipment.” Here's what satisfies it.

The code basis

IRC M1401.3 (and the IECC referenced by most states) requires heating and cooling equipment sized in accordance with ACCA Manual J and Manual S. Jurisdictions enforce it with varying strictness — some spot-check the summary, some want the full room-by-room report, and a growing number also ask for the Manual S equipment selection showing the chosen unit actually matches the calculated load.

What a complete submission includes

A Manual J eighth-edition report with: project address, the outdoor design conditions used (your county's 99% heating and 1% cooling design temperatures — reviewers check these first), indoor design conditions, construction details (R-values, window specs, infiltration), the whole-house load summary, and the room-by-room table. If ducts run through unconditioned space, duct loads should be visible.

Common rejection reasons

Design temperatures for the wrong city. Loads that obviously don't match the equipment being permitted (a 5-ton condenser on a 2.5-ton load). Rule-of-thumb worksheets instead of an actual calculation. Missing room-by-room breakdown when the jurisdiction wants one. Reports older than the current code cycle.

The timing problem

Equipment replacements are urgent — the customer has no cooling today. Traditional calc services quote 2–14 day turnarounds, which is why contractors either eat the delay or risk starting without the permit. That gap is exactly what we built for.