Patio Covers and Decks in Temecula and Murrieta: Permits and the Fire Zone Rules

In southwest Riverside County the hard part of a backyard project is almost never the design. It is finding out which set of rules your particular lot falls under, because two houses on the same street can answer that question differently.

Here is what actually governs a patio cover or a deck in Temecula, Murrieta, Wildomar and Lake Elsinore, and the layer that most homeowners here do not find out about until plan check.

First: when you need a permit at all

The thresholds are straightforward, and they catch more projects than people expect:

• A patio cover over 120 square feet needs a building permit

• Any attached patio cover needs one, regardless of size, because it becomes part of the house

• Anything with electrical in it needs one. That includes the ceiling fan, the recessed lights and the outlet you were planning to add later

• A deck whose walking surface sits more than 30 inches above the grade below needs a guard, which puts it firmly in permitted territory

The 120 square foot line is the one that surprises people. A 10 by 12 cover is 120. A 12 by 12 is not.

The layer nobody tells you about: the fire zone

This is the part that separates a Riverside County backyard project from the same project in a coastal city, and it is the reason a quote from an online calculator will be wrong.

Large parts of Temecula, Murrieta, Wildomar and Lake Elsinore sit in or directly against a Fire Hazard Severity Zone or a Wildland-Urban Interface fire area. Where that applies, Chapter 7A of the California Building Code comes with it.

Chapter 7A is not advisory. It changes what you are allowed to build out of.

The deck surface itself.

Under Section 709A.3, the walking surface of a deck has to be one of a short list of options: an ignition-resistant material that meets the performance standard, fire-retardant-treated wood for exterior use, a noncombustible material, or a material that passes the specified ASTM testing for heat release and combustion.

In plain terms: the pressure-treated pine or the plain redwood you priced at the lumber yard is very likely the wrong material for your lot. That is a cost difference, and it is better to learn it before the deposit than at inspection.

The underside of an elevated deck.

Section 707A.9 requires the underside of an elevated structure to be enclosed to grade or protected with noncombustible material, ignition-resistant material, fire-retardant-treated wood, or an assembly with a one-hour rating. There is a useful exception: structural columns and beams do not need that protection when they are sawn lumber of at least four-inch nominal dimension.

That exception is worth designing around. A heavier post can be cheaper than enclosing the whole underside.

The roof over your patio cover.

Section 705A.1 requires a Class A roof assembly, tested to ASTM E108 or UL 790. This applies to the cover, not just to the house.

The vents.

Section 706A.2 requires ember-resistant vents tested to ASTM E2886. If your cover ties into the roof or the soffit, the venting at that connection is part of the job.

Check the parcel before you draw anything

Fire hazard designation is assigned by parcel, not by city. The neighborhood on one side of a ridge can be in a zone and the one on the other side can be outside it.

Two places to confirm it: the CAL FIRE hazard severity zone maps, and your own city's building division, which will tell you exactly what applies to your address.

Do this first. Everything downstream, the material list, the drawings, the number, depends on the answer.

Every city here has its own building division

This is the second thing that catches people, particularly anyone who moved from Los Angeles or San Diego and assumes there is one process.

• Temecula, Murrieta, Wildomar, Lake Elsinore, Corona and the city of Riverside each run their own building and safety division, with their own submittal requirements, their own handouts and their own timelines

• If your address is in unincorporated county, you are not dealing with any of them. You are dealing with Riverside County Building and Safety

• Several of these cities publish pre-approved standard plans for common patio covers, which is by far the fastest route when your project fits one

Your neighbor's experience is only useful if your neighbor is in the same jurisdiction as you. In this part of the county, that is not a safe assumption.

And then there is the HOA

Across the master-planned communities in Temecula and Murrieta, the association's architectural review is a separate approval from the city permit, with its own submittal, its own committee and its own calendar.

They are not sequential by law, but they are in practice: build what the city approved but the HOA did not, and you can be asked to remove it. Start both at the same time and design to the stricter of the two.

The heat is a design input, not a complaint

Summer here runs well past 100 degrees for weeks at a time, which is why shade structures are the backyard project in this part of the county rather than a nice extra.

It also means material behavior matters more than it does near the coast. Surfaces that are comfortable in Santa Monica are not comfortable here in August, expansion and contraction are larger, and finishes fail faster on a west-facing exposure. Those are specification decisions, and they are cheap to get right at the start.

What actually moves the scope

• Whether the parcel is in a fire hazard severity zone, which changes the material list outright

• Attached or freestanding, because attached means it becomes part of the house structurally

• Whether it clears 120 square feet

• Electrical, and how far the power has to come

• Soil and footings, which on the clay soils common in parts of the county is not a formality

• Grade. A sloped yard often means a retaining element before it means a deck

• Whether a pre-approved standard plan fits, or the project needs engineered drawings

• Whether an HOA is in the loop

If the yard slopes enough that something has to hold the soil back, settle that first: retaining walls: important to know. And if the deck is elevated, the guard on it has its own set of numbers that apply statewide: guardrails and metal railings.

Common questions

Is a freestanding cover easier than an attached one?

Usually yes, because it does not have to connect to the house structure or tie into the roof and its venting. If the design allows it, freestanding is often the faster permit.

Can I build under 120 square feet and skip everything?

You can skip the permit for a small detached cover with no electrical. You cannot skip the fire zone material requirements if your parcel is in a zone, and you cannot skip the HOA.

Does an aluminum patio cover avoid the fire rules?

Noncombustible construction makes compliance much easier, which is exactly why it is common here. It still has to be permitted at the thresholds above, and it still has to be attached and footed correctly.

Do you work out here or only in Los Angeles?

Riverside County is one of the four counties we serve, alongside Los Angeles, Orange and San Bernardino. The license is the same statewide license: The Ultimate Pro, Inc., California license number 831700, Class B General Building, building in Southern California since 1996.

What does it cost?

We do not publish a figure, and in this part of the county a published figure would be worse than useless, because the fire zone answer alone can move the material cost substantially. What we will do, for free, is tell you which rules your address falls under.

Start with a free 15-minute call

Tell us the city, roughly where the property sits, whether the yard slopes, whether there is an HOA, and what you are picturing. In fifteen minutes we can usually tell you whether your parcel is likely in a fire hazard zone, whether a standard plan fits, and which building division you will be dealing with.

Call (323) 651-0635 to book the free 15-minute consultation. If your project needs a site visit and a paid assessment, we will say so on the call rather than after it.

The Ultimate Pro, Inc. California license number 831700, Class B General Building. Serving Riverside, Los Angeles, Orange and San Bernardino counties since 1996.