Walnut CreekDeck Builders

Permit rules

Deck Permits in Walnut Creek & Nearby

Most real backyard decks need a permit. Walnut Creek exempts only decks that are small, low and detached, and the other cities and Contra Costa County set their own rules.

Elevated deck on a hillside lotSide elevation of a hillside home with a deck cantilevering over a falling slope: a ledger at the house, tall braced posts on stepped footings set into the hill, open space under the deck, and oak-covered ridges with a tall peak in the distance. Ledger at the house Tall posts + bracing Footings set into slope Open space below: keep it clear Schematic, not to scale

Walnut Creek's exemption, quoted

"Decks accessory to a Group R-3 occupancy and not exceeding 200 square feet in area, that are not more than 30 inches above grade at any point, are not attached to a dwelling and do not serve the required exit door."City of Walnut Creek, Work Not Requiring a Permit
1
200 sq ft or less

A 14 × 14 ft deck is 196 sq ft; 12 × 20 is 240 sq ft and already over.

2
30 in or less above grade at any point

On a sloping yard the high corner counts, not the average.

3
Not attached to the house

A ledger bolted to the house means it is attached.

4
Not serving the required exit door

If the deck is the landing outside a required exit, it needs a permit.

All four must be true. In practice, an attached deck off a family room or any raised deck needs a permit. Exempt work still has to meet code. Apply through the Walnut Creek permit portal.

Other cities and County areas

AreaWho issues deck permitsNotes
Walnut CreekCity of Walnut CreekExemption above; online portal
LafayetteLafayette planning; building plan check and inspection by Contra Costa CountyLafayette building permits
OrindaCheck with the City of Orinda (County building inspection has been reported)Confirm before applying
MoragaTown of Moraga planning; County plan check and inspectionConfirm with the Town
DanvilleTown of Danville Building DivisionDanville Permit Center
Alamo, Blackhawk, DiabloContra Costa County (unincorporated)County permit overview

Each jurisdiction adopts the California codes with its own amendments, and exemption wording varies. Treat Walnut Creek's exemption as Walnut Creek's only.

What inspections check

  • Footings: hole size and depth before concrete, and setbacks on slopes.
  • Framing: ledger attachment and flashing, beam and joist sizes, hangers, connectors and bracing, before decking covers it.
  • Final: guards (36 in minimum on residential decks more than 30 in above grade under the California Residential Code), stairs, handrails and fire-zone materials where required.
Deck framing, side sectionSection through a deck attached to a house: decking on joists, joists hung from a ledger board that is bolted to the house with flashing above it, the outer ends resting on a beam carried by a post on a concrete footing below grade, and a guard rail along the edge. Decking (walking surface) Joists, typically 12–16 in apart Joist hanger Ledger bolted to house framing Flashing over the ledger Beam Post Footing Guard Schematic, not to scale

HOA approval and protected trees

HOAs: Blackhawk requires an architectural review application for exterior changes, and Diablo has a property owners association. Get HOA approval in hand before the permit, since design changes restart plan check.

Trees: footings near oaks need care. Walnut Creek protects trees 28 in in circumference and larger, with native oaks highly protected (WC code); Lafayette protects native trees from 12 in diameter (Lafayette); Danville protects 12 native species from 10 in and any tree 36 in and larger (Danville). Digging in a protected tree's root zone can need its own permit or an arborist's plan.

SB 721 and SB 326: not for single-family homes

California's balcony inspection laws, SB 721 and SB 326, apply to buildings with three or more units (apartments and condominium associations). They are not a requirement for single-family homeowners' decks.

Planning costs too? See the deck cost guide. In a fire zone? See fire-resistant decking.

Permit questions

Can I build a deck without a permit in California?
Only within your city's exemption. Walnut Creek exempts decks of 200 sq ft or less that are no more than 30 inches above grade at any point, not attached to the dwelling and not serving the required exit door. Anything bigger, higher or attached needs a permit.
Do I need a permit to replace deck boards?
Replacing a few boards in kind is usually treated as repair. Replacing the whole surface, railings or any framing may need a permit; ask the building department with a short description before work starts.
Do SB 721 and SB 326 apply to my house?
No. Those balcony and elevated-element inspection laws apply to buildings with three or more units (apartments under SB 721, condominium associations under SB 326), not to single-family homes.

Talk to a Walnut Creek-area deck builder

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