Remodel With New Windows and HVAC: Title 24 Checklist
Windows and HVAC end up on the same certificate because the heating and cooling load depends on the glass. Settle the window schedule first, size the equipment from it, and show both on one CF1R that carries the load calculation results. The windows need labeled ratings; the equipment needs ducts tested.
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Why one decision feeds the other
The compliance manual says the CF1R must include the results of the heating and cooling load calculations, and that everything on it must match the plans. Load methods such as ACCA Manual J, which Section 150.0(h)1 names, are driven by the envelope, glass included. Equipment sized from the old window data can end up larger than the new envelope needs.
Order of work
- Lock the window schedule. Replacements meet U-0.27 (zones 1 to 5, 11 to 14, 16) or U-0.30 (zones 6 to 10, 15), with SHGC 0.23 in zones 2, 4 and 6 to 15. Up to 75 square feet of replaced glass may use U-0.40 and SHGC 0.35 instead, except that zone 15 stays at 0.23 (Section 150.2(b)1B, Exceptions 1 and 3).
- Run the load calculation from that schedule. For an entirely new system, with the air handler, outdoor unit, coil and at least 75 percent new duct, Section 150.2(b)1C applies. Capacity has no maximum where airflow is verified at 350 cfm per ton or more; otherwise the capacity tables cap it.
- Install the windows. Temporary labels with the ratings stay on until inspection.
- Install the equipment, then call the ECC-Rater. Duct leakage, airflow and, where required, refrigerant charge are tested on the finished system.
The mistake that costs a resubmittal
Changing the glass after the CF1R is registered means a revised certificate, registered again before resubmittal, and the earlier revision is obsolete. Enlarging an opening so the net glass area in a wall grows by more than 16 square feet also brings the area limits back.
Which form goes in
The manual allows an HVAC changeout to apply with an unregistered ALT-03 or ALT-04 and present the registered CF1R-ALT-02-E at final, if the building department agrees. Once window work shares the permit, ask which form it wants at application.
Related reading: windows and Title 24, HVAC replacement, load calculations, the CF1R form and the whole-house checklist.
Common Title 24 Questions
- When is Title 24 required for a home?
- Does a remodel need Title 24?
- Does a room addition need Title 24?
- What plans are needed for a residential Title 24 report?
- How much does a residential Title 24 report cost?
- How long does a residential Title 24 report take?
Frequently Asked Questions
No. Duct testing is triggered by replacing the air handler, outdoor unit or coil, or by installing more than 25 feet of new duct. Windows affect the load calculation and the glazing limits.
The installer certifies the installation on the certificate of installation, and an ECC-Rater performs the duct leakage, airflow and charge verification on the finished system.
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View all Windows and Doors guides → · Windows and Building Envelope · Title 24 guide