California Title 24 Solar Requirements for Restaurants and Retail Buildings: A Complete Guide

For restaurant and retail companies building new locations in California, solar is no longer simply an optional sustainability investment.

Under California’s 2025 Building Energy Efficiency Standards—commonly referred to as Title 24—many newly constructed restaurants and retail buildings are required to install solar photovoltaic (PV) systems. In many cases, battery energy storage is required as well.

The 2025 Energy Code applies to permit applications submitted on or after January 1, 2026. Restaurants and retail/grocery buildings are specifically included among the building types subject to the solar requirements in Section 140.10.

For companies developing multiple locations across California, understanding these requirements early can prevent redesigns, permitting delays, and unexpected construction costs.

Here’s what restaurant and retail development teams need to know.

Which Buildings Are Required to Install Solar?

Section 140.10 of the California Energy Code requires solar PV systems on newly constructed buildings belonging to specified categories.

These include:

Restaurants
Retail and grocery
Offices
Hotels and motels
Schools
Warehouses
Medical offices and clinics
Libraries
Sports and recreation facilities
Certain multifamily buildings
Several other commercial building types

For mixed-use buildings, the requirement generally applies when at least 80% of the building’s total floor area serves one or more of the covered building types.

For a typical newly constructed standalone restaurant or retail store, that means solar should be incorporated into the project’s design from the beginning.

Do Existing Restaurants and Retail Stores Need to Add Solar?

Generally, no.

The prescriptive solar and battery requirements in Section 140.10 apply to newly constructed buildings, not ordinary additions or alterations to existing nonresidential buildings.

That distinction is important for national brands that may simultaneously be developing new locations and remodeling existing ones.

A remodel of an existing restaurant generally does not trigger the same Section 140.10 solar requirement that applies to construction of a new restaurant.

However, there is an important consideration for first-time tenant improvements.

The CEC states that an individual space in a building that has never previously been used or occupied can meet the Energy Code definition of a newly constructed building. First-time tenant improvements subject to permits submitted on or after January 1, 2026 can therefore be subject to the applicable solar and battery requirements.

How Much Solar Does Title 24 Require?

One of the most common misconceptions about Title 24 is that every restaurant or retail building must install a predetermined solar system size.

It doesn’t work that way.

Under the prescriptive approach, Section 140.10 establishes two calculations, and the required PV capacity is generally based on the smaller result.

Method 1: Conditioned Floor Area

The first calculation uses the building’s:

Conditioned Floor Area × PV Capacity Factor

The PV capacity factor is established by the Energy Code and varies based on both building type and California climate zone.

This is particularly important for restaurants and retailers because the 2025 Energy Code increased PV capacity factors for restaurants, retail, grocery and several other building types.

A restaurant of the same size can therefore have different prescriptive solar requirements depending on where in California it is constructed.

Method 2: Solar Access Roof Area

The second method looks at the building’s available Solar Access Roof Area, or SARA.

For purposes of determining the PV requirement, available SARA is multiplied by:

14 watts per square foot for low-sloped roofs

18 watts per square foot for steep-sloped roofs.

The required PV system is generally the smaller of the capacity determined by the conditioned-floor-area calculation and the applicable SARA calculation.

Parking Structures Can Matter Too

One particularly important issue for restaurants and retailers is the definition of SARA.

SARA isn’t necessarily limited to the roof of the primary building.

The Energy Code states that SARA can include roof space on covered parking areas, carports, and other newly constructed structures on the site that are compatible with supporting PV.

This can make solar canopies especially relevant for restaurant and retail developments.

Many restaurants have relatively small rooftops filled with HVAC equipment, exhaust systems, vents, and other obstructions while having significantly larger parking areas.

Solar canopies can therefore provide another way to integrate the required PV system into the development while simultaneously creating shaded parking and potentially providing infrastructure for future EV charging.

Are There Exceptions to the Solar Requirement?

Yes.

The Energy Code provides several exceptions that can eliminate the PV requirement in specific circumstances.

For example, PV may not be required if:

Total available SARA is less than 3% of conditioned floor area.
The calculated minimum PV requirement is less than 4 kW DC.
Available SARA contains less than 80 contiguous square feet.
Certain snow-load requirements prevent installation.
Certain qualifying small tenant spaces within multitenant buildings meet specific requirements.

The small-tenant exception generally applies to tenant spaces of 2,000 square feet or less that have their own HVAC system and individual utility meter, subject to additional conditions in the code.

These exceptions should be evaluated on a project-by-project basis rather than assumed to apply based solely on building size.

Does Title 24 Require Batteries?

This is where the 2025 Energy Code becomes particularly important for commercial development teams.

Buildings subject to the Section 140.10 solar requirement are generally also required to install a battery energy storage system (BESS) unless an exception applies.

Battery size isn’t simply a fixed percentage of the solar system.

The prescriptive requirements use specific equations to determine minimum usable energy capacity in kWh and minimum power capacity in kW. The calculation incorporates factors including conditioned floor area, building type, climate zone, required PV capacity, SARA adjustments where applicable, and battery round-trip efficiency.

The battery must also satisfy applicable CEC performance and certification requirements.

The 5,000-Square-Foot Battery Exception

For restaurants in particular, one exception is extremely important.

Under the 2025 Energy Code, a single-tenant building with less than 5,000 square feet of conditioned floor area does not have to install a battery under Section 140.10(b).

For multitenant buildings, the BESS energy-capacity calculation is based on tenant spaces exceeding 5,000 square feet of conditioned floor area.

That means a new 4,000-square-foot standalone restaurant may still have a solar requirement without having a battery requirement.

There are also other BESS exceptions. A battery may not be required if the calculated usable capacity is less than 10 kWh or if the installed PV system falls below the threshold specified by the code.

Solar and battery requirements therefore need to be evaluated separately.

Prescriptive vs. Performance Compliance

The calculations described above are part of the prescriptive compliance approach.

California also allows projects to demonstrate Energy Code compliance using an approved performance approach.

Under performance compliance, the proposed building’s modeled energy consumption is compared against the energy budget of a standard design building. Design decisions elsewhere in the building can therefore affect the ultimate compliance strategy.

For example, the CEC notes that increasing building energy efficiency can potentially reduce the required PV system size under the performance approach. Larger battery systems can also provide compliance tradeoffs in certain circumstances.

For developers, this means the Title 24 consultant, architect, electrical engineer, solar provider, and other design professionals should coordinate early rather than treating solar as an equipment package to be added at the end of design.

Why Multi-Site Companies Need a Standardized Process

Title 24 becomes considerably more complicated when a company is developing 10, 50, or 100 California locations.

Every project can have a different:

Climate zone
Conditioned floor area
Solar requirement
Battery requirement
Roof configuration
Parking configuration
Electric utility
Interconnection process
Local permitting authority
Construction schedule

Managing each location independently can create unnecessary cost and complexity.

A better approach is to establish a repeatable Title 24 solar process within the company’s new-store development program.

As soon as a new California location enters development, the company should determine its Title 24 applicability, calculate the minimum PV and battery requirements, identify the preferred system location, coordinate the system with the building design, and incorporate solar into the permitting and construction schedule.

For multi-site brands, standardized equipment, drawings, procurement, installation processes, and portfolio reporting can make compliance considerably easier.

Turn a Requirement Into an Investment

Title 24 creates a compliance obligation, but compliance doesn’t have to be the end goal.

If a company is already required to install solar, the more valuable question may be:

Should we install only the minimum system required by Title 24, or should we optimize the project for financial return?

A larger system may sometimes produce better economics by reducing more utility purchases. Solar canopies may unlock additional generating capacity. Battery storage may provide economic benefits beyond compliance. Federal, state, utility, or local incentives may further improve project returns.

The best solution therefore isn’t necessarily the smallest system that satisfies the building code.

It is the system that meets the Title 24 requirement while creating the greatest long-term value for the property and the business.

At Integrate Solar, we help restaurant, retail, and other multi-location companies manage this entire process—from determining Title 24 solar and battery requirements through design, permitting, installation, utility interconnection, portfolio reporting, and ongoing system performance.

For companies building across California, the objective is simple: make Title 24 solar compliance predictable, repeatable, and profitable.

This article is intended for general informational purposes. Title 24 requirements can vary based on building design, occupancy, compliance approach, permitting date, and other project-specific factors. Project requirements should be confirmed by the appropriate design professionals and authority having jurisdiction.