CA Title 24 Energy Standards & Contractor Risk

What Title 24 actually requires, in plain terms

Title 24, Part 6 of the California Code of Regulations sets minimum energy performance standards for new construction and many renovation projects statewide. It doesn't just regulate one system — it sets requirements across the building envelope (insulation, air sealing, window performance), electrical systems (lighting controls and, in recent code cycles, solar- and EV-readiness), and mechanical systems (HVAC equipment efficiency and ductwork sealing), all calculated together against a performance target rather than judged trade-by-trade in isolation.

Requirements vary by California's climate zones, and the standards are updated on a multi-year code cycle — what a project needed to meet under an earlier cycle isn't necessarily what a similar project needs today. Confirming which code cycle and climate zone actually applies to a specific project, rather than assuming based on a past job, is the starting point for every trade involved.

Covers building envelope, electrical systems and mechanical systems together

Requirements are calculated against a whole-building performance target

Standards vary by California climate zone and update on a multi-year cycle

Confirm the applicable code cycle for each specific project — don't assume

Is this a California-only requirement?

Yes — Title 24 is specific to California. It's Part 6 of the California Code of Regulations, adopted by the California Building Standards Commission and updated on a multi-year cycle by the California Energy Commission. None of the other states GIB serves use this designation or these specific requirements.

That doesn't mean Arizona, Nevada, Texas and Utah have no energy code at all — each has adopted some version of the International Energy Conservation Code (IECC), but inconsistently and on its own timeline. Arizona has no single statewide energy code at all; adoption happens city by city. Nevada adopted the 2024 IECC statewide. Texas is currently on the 2021 IECC (2021 IRC for residential, ASHRAE 90.1-2019 for commercial), with a move to the 2024 IECC under consideration but not yet adopted. Utah's commercial code has been based on the 2018 IECC, with legislation to move toward the 2024 IECC in progress.

The practical takeaway for a contractor working across more than one of these states: don't assume a compliance approach, a rough-in requirement or a documentation habit that satisfies Title 24 in California automatically satisfies whatever code applies on a job in Nevada, Texas, Arizona or Utah — confirm the actual adopted code and jurisdiction-specific amendments for each state and project, rather than treating one state's rules as the default.

Title 24 is unique to California — no other state uses this designation

AZ, NV, TX and UT each use some version of the IECC instead, on different timelines

Arizona has no single statewide code — adoption is city by city

Confirm the actual adopted code for each specific state and project

Insulation and air sealing: the building envelope side

Insulation contractors are working against climate-zone-specific performance requirements for walls, floors and ceilings, plus air-sealing standards that treat the building envelope as one connected system rather than isolated components. On new construction, unvented ('conditioned') attic assemblies using spray foam insulation at the roofline — rather than at the ceiling — have become a common compliance strategy, since it brings ductwork and equipment that would otherwise sit in a hot, unconditioned attic into the building's thermal envelope, a meaningful factor in the whole-building energy calculation.

Field verification matters here as much as the installation itself — a HERS (Home Energy Rating System) rater typically has to verify insulation installation and air-sealing quality on a compliance-relevant project before it can close out. An insulation contractor's own documentation of what was actually installed, and where, is what supports that verification rather than leaving it to be reconstructed after the fact.

Envelope requirements are climate-zone-specific and treated as one connected system

Spray foam, unvented attic assemblies are a common new-construction compliance strategy

Moving ductwork into conditioned space is a real factor in the energy calculation

HERS rater field verification is typically required — document the actual installation

Roofing: cool-roof and radiant-barrier requirements

Certain roof assemblies are subject to their own solar reflectance and thermal emittance requirements under Title 24, intended to reduce heat gain into the attic and the building below — this is the 'cool roof' side of the code, and it's a real factor in material selection, not just an energy-bill talking point. Reflective roofing membranes and radiant-barrier OSB roof sheathing (a reflective foil layer bonded to structural sheathing) are both recognized ways roofing contractors help a project meet that requirement, on top of whatever the insulation contractor is doing at the attic floor or roofline.

Radiant barrier and cool-roof requirements interact directly with how the attic assembly is insulated — a roofing contractor and an insulation contractor working the same new-construction project genuinely need to know what the other is installing, since the two systems are evaluated together, not independently, when the project's energy compliance is verified.

Certain roof assemblies carry their own reflectance/emittance requirements

Radiant-barrier OSB sheathing and reflective membranes are recognized compliance paths

Roof assembly and attic insulation are evaluated together, not independently

Coordinate with the insulation contractor on the same project before installing either

Electrical and HVAC: the systems side

Electrical contractors are working against lighting power allowances and mandatory lighting controls under Title 24, and recent code cycles have added solar-ready, battery-storage-ready and EV-charging-readiness requirements to new residential construction — meaning conduit, panel capacity and dedicated circuits sometimes have to be roughed in for systems that won't be installed until later. Missing one of these readiness requirements at rough-in is a common, expensive callback once it's discovered at final inspection or by a HERS rater.

On the mechanical side, HVAC equipment efficiency ratings and ductwork sealing are both directly regulated, and duct sealing in particular is typically subject to its own field verification and testing — ductwork that passes a visual inspection can still fail the actual sealing test a HERS rater or approved tester runs before the system is signed off.

Lighting power allowances and mandatory controls apply to most new construction

Solar-, battery- and EV-charging-readiness rough-ins are now commonly required

Missing a readiness requirement at rough-in is a common, costly callback

Duct sealing is typically field-tested, not just visually inspected

Why this is worth thinking about as an insurance question, not just a code question

A project that fails Title 24 field verification doesn't just create rework cost — it can create a dispute with the GC or builder over who's responsible for the callback, and depending on when the failure is discovered, it can turn into a completed-operations claim if the work was already signed off and later found non-compliant during a later inspection, sale, or renovation. Clear documentation of what was actually installed, by which trade, and when, is what actually supports a contractor's position if that dispute happens months or years after the work was done.

For a contractor doing enough Title 24-relevant work — new construction insulation, roofing, electrical rough-in or HVAC installation — that this is a real and recurring part of the job, it's worth confirming with a broker that completed operations coverage and documentation practices actually match how this specific compliance risk plays out, rather than assuming a general contractor or trade policy already accounts for it.

A compliance failure can become a dispute over responsibility, not just a rework cost

A failure found after sign-off can turn into a completed-operations claim later

Documentation of what was installed, by whom and when, supports your position

Confirm coverage and documentation practices match this specific compliance risk