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Building Code Reference

Got a CALGreen 4.503.1 correction?

Direct-vent sealed-combustion fireplace

For builders in California, Greater Seattle, the Las Vegas area, the Denver area and Kansas City · CrossBeam Permits

What this code requires, how to fix it, and how cities and counties review it

What this code requires

CALGreen 4.503.1 requires that any gas fireplace installed in new residential construction be a direct-vent sealed-combustion type. Woodstoves and pellet stoves must meet U.S. EPA NSPS emission limits and carry a permanent certification label, and woodstoves, pellet stoves and fireplaces must also comply with applicable local ordinances, which in many areas restrict open-hearth and wood-burning units. The requirement applies to new single-family homes and low-rise residential buildings permitted under Title 24 Part 11.

How to fix it

  1. Specify direct-vent or sealed-combustion on the fireplace schedule

    On your mechanical or architectural schedule, add a dedicated fireplace fixture row. The spec must state: type (direct-vent sealed-combustion), manufacturer, model number, and vent path. 'Direct-vent sealed-combustion type' is the exact term in the code, so use it as written, not a paraphrase. Plan-checkers match your language against the code text, and an exact match speeds review. Include the BTU input rating and whether the unit is approved for installation in a zero-clearance or framed chase, since that affects the structural notes on the same sheet.

  2. Check any open-hearth or wood-burning unit against local rules

    CALGreen 4.503.1 does not itself ban wood-burning fireplaces. It requires gas fireplaces to be direct-vent sealed-combustion, requires woodstoves and pellet stoves to meet U.S. EPA NSPS limits with a permanent label, and requires woodstoves, pellet stoves and fireplaces to comply with applicable local ordinances. Many cities and air districts restrict wood-burning units in new homes. If local rules bar the unit your plans show, delete it from every affected sheet: floor plan, exterior elevation, and the mechanical schedule. Do a text search in your CAD or PDF for 'fireplace,' 'hearth,' and 'wood' to catch any stray references.

  3. Confirm the woodstove or pellet stove model is EPA NSPS certified

    If you're specifying a woodstove or pellet stove, verify it has an EPA NSPS permanent certification label before you put it on the drawings. Check the EPA's Certified Wood Heaters database to confirm the exact model number is listed. Print or save a screenshot of the EPA listing and include it in your resubmittal package. Plan-checkers will ask for this documentation; having it ready in the first resubmittal prevents a second correction cycle. The physical label must be on the unit when the inspector does the rough-in or final inspection, so confirm your supplier includes it.

  4. Show the vent termination on the elevation drawing

    Direct-vent units exhaust through a co-axial pipe terminating at the exterior wall or roof. Add the vent termination symbol and label on at least one exterior elevation sheet. Note the clearance to windows and doors per the manufacturer's installation instructions, typically 12 inches minimum to an operable opening but confirm with the specific model's listing. Label the vent type and the listed product series on the drawing. This detail helps the building inspector confirm correct clearances at rough-in and avoids a field correction that stalls your final inspection.

  5. Add a CALGreen 4.503.1 compliance note to the cover sheet

    Add a general note to your cover sheet or notes sheet citing the code explicitly. Something like: 'All gas fireplaces are direct-vent sealed-combustion type per CALGreen Section 4.503.1, 2025 California Green Building Standards Code (Title 24 Part 11).' This note signals to the plan-checker that the requirement was addressed on purpose, not overlooked. It also gives the field inspector a reference to verify against during inspection. If you have multiple fireplace locations, list each one by room and sheet reference under the note.

  6. Cross-check the energy compliance forms for consistency

    Your Title 24 Part 6 energy compliance forms (CF1R and CF2R) may also reference the fireplace. Confirm the fireplace type shown on those forms matches the mechanical schedule. Mismatches between the T24 energy forms and the mechanical drawings are a frequent second-round correction because the energy plan-checker and the building plan-checker sometimes work from different sheets. Run a final cross-check before resubmitting: search every sheet for 'fireplace' and verify each instance states direct-vent sealed-combustion.

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Why you got flagged

Most corrections on 4.503.1 come down to one thing: the plans show a gas fireplace without specifying that it's a direct-vent sealed-combustion type. Plan-checkers won't approve what they can't verify, and a fireplace spec that just says 'gas insert' or 'see manufacturer' gives them nothing to confirm compliance.

A second common reason is that the architectural drawings show a traditional open-hearth or wood-burning fireplace, either by habit or because the design came from an older template. CALGreen 4.503.1 does not ban them outright, but it requires fireplaces to comply with applicable local ordinances, and many local rules restrict wood-burning units in new homes. Where that applies, swapping the spec to a direct-vent gas unit is the usual fix.

Pellet stoves and woodstoves cause their own headaches. Contractors often spec these without confirming that the unit has an EPA NSPS permanent certification label. The label must be visible on the unit itself, not just in a spec sheet or cut sheet. If the model isn't EPA-certified, you're back to square one.

Less common but still seen: a remodel or addition that ties into an existing open-hearth fireplace. If the project involves new construction on the same permit, even if the fireplace is existing, plan-checkers sometimes flag it under 4.503.1 until the applicant clarifies scope. Getting ahead of this with a clear note on the plans saves a review cycle.

The official code

CALGreen 4.503.1 — 2025 California Green Building Standards Code, Title 24 Part 11 (California Building Standards Commission)

Read the source →

Common questions

Does CALGreen 4.503.1 apply to remodels or only new construction?
The requirement primarily targets new residential construction. If you're doing an addition, the new portion of the project typically must comply with current CALGreen, including 4.503.1 if a fireplace is part of that addition. Replacing an existing open-hearth fireplace with a like-for-like unit on a repair permit is a gray area. Some jurisdictions allow repair-in-kind; others require the replacement to meet current code. The safest call is to contact your local building department before specifying the replacement unit. If the replacement is going on a full remodel permit that triggers CALGreen compliance, a new gas fireplace will need to be a direct-vent sealed-combustion type regardless of what was there before.
Can I install a wood-burning fireplace in a new home in California?
It depends on local rules. CALGreen 4.503.1 does not ban wood-burning fireplaces itself; it requires woodstoves, pellet stoves and fireplaces to comply with applicable local ordinances, and many cities and air districts restrict wood-burning units in new homes. A woodstove or pellet stove meeting EPA NSPS with a permanent label, or a direct-vent sealed-combustion gas fireplace with a log set, meets CALGreen. High fire hazard severity zones (VHFHSZ) and state responsibility areas (SRA) may have local ordinances that go further, sometimes banning any solid-fuel burning device entirely. Check your city's local ordinance and the CalFire map if the property is in a fire-prone zone.
What's the difference between direct-vent and sealed-combustion fireplaces?
Both types are compliant under CALGreen 4.503.1, and modern gas inserts are often described as both. A direct-vent unit draws combustion air from outside through a dedicated pipe and exhausts combustion gases through a co-axial duct, keeping indoor air completely out of the combustion process. A sealed-combustion unit takes this further: the combustion chamber is physically isolated from the living space so indoor air never contacts the flame or exhaust gases. For plan-check purposes, specifying 'direct-vent' on your schedule satisfies 4.503.1 for gas fireplaces. Confirm with your supplier that the listed model meets the definition, and carry the manufacturer's installation guide to the field inspection.
What does 'EPA NSPS permanent certification label' mean for woodstoves?
The EPA New Source Performance Standards (NSPS) set emission limits for wood-burning and pellet-burning heaters. A stove that meets NSPS has been tested by an accredited lab and certified by the EPA to those limits. The certification label is physically affixed to the unit, not just listed in the product literature or on the manufacturer's website. You can verify a specific model at the EPA's Certified Wood Heaters database online. For plan check, note the manufacturer, model number, and EPA listing number on your mechanical schedule. At rough-in or final inspection, the building inspector will look for the physical label on the stove, so confirm your supplier ships the unit with it attached and undamaged.
My corrections letter cites 4.503.1 but I have no fireplace on the plans. What happened?
A few things can cause this. The plan-checker may have flagged a symbol or detail that looks like a hearth, raised hearth, or fireplace chase even if it's not labeled as one. Check your floor plan for any raised slab, decorative niche, or framed chase that could be misread. It could also be a note in the general specs that references a 'fireplace option' as a future owner upgrade. Plan-checkers sometimes flag conditional items to get a response on the record. If you genuinely have no fireplace on this project, write a correction response note: 'No fireplace is proposed. CALGreen 4.503.1 does not apply to this project. See sheet [X].' Point to the specific sheet and detail that confirms no fireplace. This typically resolves in one round.
Does 4.503.1 apply to ADUs?
Yes. ADUs are residential construction under Title 24 Part 11, so CALGreen applies to new ADU construction. If the ADU includes a fireplace or woodstove, 4.503.1 applies to that unit the same as it would to the primary dwelling. Attached ADUs are usually included in the primary home's CALGreen checklist and reviewed under the same permit. Detached ADUs get a separate permit but still fall under full CALGreen compliance requirements for new construction. Open-hearth fireplaces are not allowed in ADUs any more than they are in the primary dwelling under the 2025 code.

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