SCAQMD Rule 1146.2 Compliance Extension Options
If your compliance deadline under SCAQMD Rule 1146.2 is approaching and you are facing a genuine obstacle to meeting it on time, you are not without options.
The rule includes formal alternative compliance pathways for building owners and operators who cannot install zero-emission equipment by their applicable deadline due to circumstances outside their control.
Each one is specific, with defined eligibility criteria, documentation requirements, and filing deadlines.
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What Are Your Options If You Cannot Meet the SCAQMD Rule 1146.2 Deadline?
First, confirm the rule applies to you. Rule 1146.2 covers natural gas units with a rated heat input capacity of 2,000,000 Btu per hour or less. If yours is larger, Rules 1146 and 1146.1 apply instead and nothing below is relevant to your situation.
Rule 1146.2 contains six alternative compliance options. This article covers the five that apply to commercial and industrial buildings. The sixth is a narrow provision for instantaneous water heaters in mobile homes, which we note briefly at the end.
For background on the rule itself and how to determine which deadline applies to your building, see our article on SCAQMD Rule 1146.2 explained.
Why Deadlines Cannot Simply Be Ignored
Once your unit is required to meet the zero-emission limits, you are not permitted to keep operating it as it is. There is no grace period and no transition window, so if you have no approved alternative compliance option in place, you are in violation the day your obligation begins.
For a unit already in operation, two conditions apply, and both must be true before zero-emission compliance is required. The first is the calendar deadline for your phase and building type. The second is your unit’s age. Whichever of the two arrives later is your effective compliance date.
Table 1: Current NOx Emission Limits (Concentration-Based)
| Equipment Category | NOx Emission Limit | CO Emission Limit |
|---|---|---|
| Type 1 Units, excluding Pool Heaters | 14 ng/J or 20 ppmv | N/A |
| Type 1 Pool Heaters | 40 ng/J or 55 ppmv | N/A |
| Type 2 Units | 14 ng/J or 20 ppmv | 400 ppmv |
Type 1 units are not subject to a CO limit under Rule 1146.2, though they may be subject to CO limits under other AQMD rules.
Table 1 governs what may be manufactured, sold, or installed before the zero-emission dates arrive. It is not applied retroactively to equipment already in service. The one operating limit the rule does place on older equipment is for Type 2 units manufactured before January 1, 2000, which may not be operated above 30 ppmv NOx and 400 ppmv CO.
Table 1 is also the standard any temporary unit must meet during the extension periods described in this article.
Table 2: Zero-Emission Limits, Unit Ages, and Compliance Phases
| Equipment Category | Rated Heat Input Capacity | Zero-Emission Limit | Compliance Phase | New Building Deadline |
|---|---|---|---|---|
| Type 1 Unit | ≤ 400,000 Btu/hr | 0 ppmv NOx & CO | Phase I | Jan. 1, 2026 |
| Instantaneous Water Heater | ≤ 200,000 Btu/hr | 0 ppmv NOx & CO | Phase I | Jan. 1, 2026 |
| Instantaneous Water Heater | > 200,000 to ≤ 2,000,000 Btu/hr | 0 ppmv NOx & CO | Phase II | Jan. 1, 2028 |
| Type 1 Pool Heater | ≤ 400,000 Btu/hr | 0 ppmv NOx & CO | Phase II | Jan. 1, 2028 |
| Type 2 Unit | > 400,000 to ≤ 2,000,000 Btu/hr | 0 ppmv NOx & CO | Phase II | Jan. 1, 2028 |
| Type 1 High Temperature Unit | ≤ 400,000 Btu/hr | 0 ppmv NOx & CO | Phase III | Jan. 1, 2029 |
| Type 2 High Temperature Unit | > 400,000 to ≤ 2,000,000 Btu/hr | 0 ppmv NOx & CO | Phase III | Jan. 1, 2029 |
Table 3: Compliance Dates for Zero-Emission Limits
| Phase | Building Type | Compliance Date |
|---|---|---|
| Phase I | New Buildings | January 1, 2026 |
| Phase I | Existing Buildings | January 1, 2029 |
| Phase II | New Buildings | January 1, 2028 |
| Phase II | Existing Buildings | January 1, 2031 |
| Phase III | New Buildings | January 1, 2029 |
| Phase III | Existing Buildings | January 1, 2033 |
To use these together:
Take a standard Type 1 unit in an existing building. Your deadline is January 1, 2029, and your age limit is 15 years, counted from the date the unit was built. If it is already past 15 by then, you comply on January 1, 2029. If it was built in 2020, it does not turn 15 until 2035, so that is your compliance date.
One caution on age. If you cannot substantiate the unit’s original manufacture date through an invoice, the manufacturer’s rating plate, or another method the Executive Officer accepts, the rule deems the unit to have reached the end of its age as of January 1, 2025. Missing documentation defaults against you.
A different rule applies to new equipment. Manufacturing, selling, or installing a unit is governed by the Table 3 date alone, with no age condition attached. Once your phase date arrives, only zero-emission equipment may be installed.
None of the options below happen on their own. Two of them, the utility upgrade extension and the multiple-unit plan, require written approval from the AQMD Executive Officer before your compliance date. The other three are granted once you meet the stated conditions and report on time, but the reporting is mandatory and the deadlines are firm.
If you think you may need an extension, the time to act is well before your deadline, not after it passes.
Option 1: Utility Upgrade Extension
Who it is for:
This is the most common obstacle for buildings transitioning from natural gas to electric or heat pump water heating. Heat pump water heaters and electric resistance units require dedicated electrical circuits and, in many older buildings, panel upgrades or new service capacity that the utility must provide.
If the utility company’s timeline for completing that work extends past your compliance date, you may qualify for this extension.
How it works:
You may request an extension of up to 24 months from your applicable compliance date. Notify the AQMD Executive Officer through the Compliance Portal at least 90 days before your compliance date, explaining that a utility upgrade is required and that the utility cannot provide the necessary power in time.
Notification alone is not enough. You must obtain a letter from the Executive Officer approving the extension before your compliance date arrives. Filing the request and assuming the extension is in place will leave you in violation if approval does not come through.
If your unit has already failed:
There is a second route into this option. If the utility upgrade is needed to power a replacement for a unit that failed and is no longer operational, you have 30 days from the date the unit went out of service to request the extension. In that case the 24 months run from the date of failure rather than from your compliance date, and the Executive Officer’s decision comes within 90 days of your notification.
Reporting during the extension:
You must submit a progress report to AQMD every six months. Each report covers the status of the utility upgrade, the utility company’s estimated completion date, and documentation supporting that estimate.
You must also notify AQMD within 72 hours of installing the compliant unit.
If 24 months is not enough:
The rule allows one additional extension of up to 24 months, requested at least 90 days before the initial extension ends and approved in writing before it ends. If the work still is not finished, one further extension of up to 12 months is available on the same terms. That is the end of the sequence. Three periods, 60 months maximum, and each one requires its own request and its own approval letter.
During the extension:
If your unit is non-operational, you may run a temporary unit that meets the Table 1 emission limits while the permanent compliant unit is arranged. Notify AQMD within 72 hours of installing the temporary unit and again within 72 hours of disconnecting it. This applies to units that are out of service. A unit still running is not eligible for a temporary replacement.
What you need to document:
An official document from the utility company, signed by a responsible party, explaining the required upgrade, when the request was made, the estimated completion date, and confirmation that the delay is outside your control. Keep these records for three years after the extension ends.
Option 2: Alternative Compliance Plan for Multiple Units
Who it is for:
If you manage a portfolio of properties or a large facility with multiple boilers or water heaters, having all of them reach compliance at once can create a logistical and financial burden. The Alternative Compliance Plan lets you stagger the replacement schedule across a defined period rather than replacing everything simultaneously.
How it works:
Submit a formal alternative compliance plan to the AQMD Executive Officer at least one year before the earliest compliance due date among your units, with a filing fee pursuant to AQMD Rule 306.
The plan specifies compliance dates for each unit on the following schedule:
three units or at least 30 percent of them by the latest applicable compliance date; at least 30 percent within one year after that date; and the remainder within two years after that date.
Approval:
The Executive Officer reviews the plan and provides written approval or disapproval before your earliest compliance date. Approval depends on meeting the eligibility criteria:
five or more units required to meet Table 2 limits within two consecutive calendar years, and a plan submitted at least one year in advance.
If utility upgrades create further delay:
A plan affected by utility infrastructure limitations can carry an extension of up to 24 months from the earliest compliance due date, but the mechanics differ from Option 1 in three ways worth planning around.
First, taking this path replaces the staggered schedule above. Three units or at least 50 percent of them must comply within 24 months after the extension ends, and the remainder within 36 months.
Second, each further extension requires a revised alternative compliance plan, not a portal request. You file it at least 180 days before the current extension ends, with a new Rule 306 filing fee, and you need Executive Officer approval each time.
Third, the sequence is the same length as Option 1 but reached differently: 24 months, then a second 24 months, then a final 12 months. You also owe a progress report every six months throughout, covering the utility upgrade status, the estimated completion date, and documentation supporting it.
Option 3: Emergency Replacement Extension
Who it is for:
This option addresses the case where you had no advance warning of the failure and compliant replacement equipment cannot be installed immediately because the electrical infrastructure is not yet in place.
How it works:
You may install a temporary unit that meets the Table 1 emission limits for up to six months while you arrange the permanent compliant unit and the necessary electrical work. Three reports are required through the Compliance Portal, each within 72 hours: the unit failure and temporary installation, the date the temporary unit is disconnected, and the date the compliant replacement is installed.
Where it does not apply:
This option is for genuine emergencies involving sudden unit failure, not for planned replacements where a compliant unit was not arranged in advance of the compliance date. It is also unavailable if you are already using the utility upgrade extension, the leased property extension, or the construction extension.
Residential structures fall under a separate provision, which allows a manufacturer, distributor, retailer, or installer to rent out a Table 1 unit for up to six months.
Option 4: Leased Property Extension
Who it is for:
How it works:
The rule provides an extension of up to 24 months from the applicable compliance date once you meet its conditions. You must occupy the property as a tenant under a lease that was in place both before and after the compliance date, and you must report to AQMD through the Compliance Portal no later than 90 days before your compliance date.
Unlike Options 1 and 2, there is no approval letter to wait for. The extension follows from meeting the conditions. The reporting deadline is what makes or breaks it, so a missed 90-day report costs you the option entirely.
This option is not available if you are already using the utility upgrade extension, the multiple-unit plan, or the construction extension.
During the extension:
If the unit is non-operational, you may run a temporary unit meeting Table 1 limits, with the same 72-hour notifications on installation and disconnection. You must also report the installation of the compliant unit within 72 hours.
What you need to document:
A legally binding contract explaining the terms and duration of the tenancy under which you rent from the landlord, and documentation showing that the installation delay is beyond your reasonable control.
Keep these for three years after you report through the portal.
Option 5: Construction Delay Extension
Who it is for:
This is the option relevant to renovation projects where the mechanical room or equipment space needs to be modified or enlarged before the compliant unit can be installed. It is covered in more detail in our article on the SCAQMD 2026 compliance deadline and new construction, which addresses how this applies in a project context.
How it works:
The rule provides an extension of up to 18 months from the applicable compliance date, granted on the same basis as Option 4. Report to AQMD through the Compliance Portal no later than 90 days before your compliance date, and report the compliant installation within 72 hours of completing it. As with the leased property option, a temporary unit meeting Table 1 limits is available if the unit is non-operational, subject to the 72-hour notifications.
This option is not available if you are already using the utility upgrade extension, the multiple-unit plan, the mobile home provision, or the leased property extension.
What you need to document:
Images showing the construction activity, the expansion or relocation of the equipment space, and the associated equipment affected by the construction, plus documentation of the construction itself. A construction permit works, and so does a contract.
Filing Deadlines Decide Which Options Stay Open
Every option covered in this article requires you to act before your compliance date. Most carry a 90-day filing deadline. The Alternative Compliance Plan requires a full year. If you wait until your compliance date has passed to start looking into these options, most of them are closed to you.
The emergency replacement option is the exception among the five, since a sudden failure cannot be filed for in advance. It carries its own strict 72-hour reporting requirements instead, and it only covers genuine equipment failures.
For equipment selection once you are ready to move forward, see our article on SCAQMD certified boilers and the approved equipment list.
Sources: South Coast AQMD Rule 1146.2 (amended June 7, 2024), Rule 1146 (amended December 4, 2020), and Rule 1146.1 (amended December 7, 2018), available at aqmd.gov.
Where Porter Boiler Fits In
Porter Boiler Service handles SCAQMD compliance work across Los Angeles, Long Beach, Orange County, and the broader Southern California area. We work with building owners and facility managers on certified unit selection, installation, and AQMD permitting.
Over 65 years in Southern California means we have worked through these requirements as they have changed, and we know what each compliance situation actually requires.
If you are facing a compliance deadline and need to understand your options before taking any action, we can help you assess the situation and move in the right direction.