Do I Have to Bring My Existing Home Up to Title 24? What "Grandfathered" Really Means
No. The Energy Code does not reach back to a house because it is old or changes hands. It attaches when a permit application is filed, and then only to the new construction in the building: an addition, or the components an alteration touches. Pure repairs sit outside it.
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Owning an older house triggers nothing
Part 6 applies to a building when an application for a building permit, or the renewal of an existing permit, is filed on or after the effective date (Section 100.0(a)2). An existing building is one erected before the current code was adopted or one with a legal permit already issued, and Section 150.2 reaches it only when additions, alterations or repairs are permitted. Age, ownership and a sale do not appear in that scope.
What a permit does reach
- An addition must meet the requirements Section 150.2(a) sets for additions.
- An alteration brings up the altered component and any new equipment serving it (Section 150.2(b)1). When the performance route is used, components that are not altered are judged on their existing conditions (Section 150.2(b)2B).
For alterations without field verification, and for additions under 300 square feet without it, the building department may waive or simplify the certificate paperwork (Part 1, Section 10-103(a)1C and 3D).
Three borderline cases
Repair or alteration. The compliance manual says the code applies to additions and alterations, not repairs, but replacing any component the Standards regulate counts as an alteration. See repair versus alteration.
A permit that comes back to life. Renewal of an existing permit is itself a trigger, and a permit that expired with no construction is re-judged under the code on the new application date (Section 10-103(d)1). See expired permits.
Work done years ago without a permit. The Commission's ADU FAQ says that if the building was not permitted before and an application is submitted now, it must meet the applicable Energy Code requirements, and the building department decides whether it is treated as new or as an addition. See legalizing unpermitted construction.
Who is excepted outright
Qualified historic buildings under the California Historic Building Code, temporary buildings at the department's discretion, and Group I-3 and I-4 buildings (exceptions to Section 100.0(a)). Others are on Title 24 exemptions.
Planning a permit? Remodel Title 24 shows what the job needs, and selling a house covers sales. A residential report is the certificate.
Common Title 24 Questions
- What is Title 24?
- Do I need a Title 24 report?
- How much does a Title 24 report cost?
- How long does a Title 24 report take?
- What is included in a Title 24 report?
- What plans do I need to upload?
Frequently Asked Questions
Part 6 attaches to permit applications, not to sales, so the Energy Code does not require an upgrade at sale. A city may have separate rules, so ask the building department.
No. The altered component and the new equipment serving it must meet the requirements. Parts you are not altering keep their existing conditions.
Explore What Is Title 24?
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- Mandatory, Prescriptive and Performance: The Three Parts of Every Title 24 Report
- What Are the Parts of Title 24, and Which Is the Energy Code?
View all What Is Title 24? guides → · Title 24 Guide · Title 24 guide