Slab, Footing or Pavers? Choosing a Base for a Pergola or Outdoor Kitchen

“Do we need a slab under this?” is the wrong first question for a pergola or outdoor kitchen. The right one is what sits on top of the base — a light shade structure, a timber-framed roof, or a stone-veneer kitchen island — because that decides whether pavers are enough, a thin slab works on its own, or the posts need individual footings. Code answers differ by what the base is asked to carry, not by what looks nicest in a plan.

Three things called a “base”

Homeowners planning a pergola or outdoor kitchen often ask us to compare pavers, concrete and “footings” as if they were competing finishes. They are not interchangeable — each does a different structural job.

An outdoor kitchen often needs two of these at once: pavers or a slab for the walking surface, and a thickened slab edge or separate footing under the counter where the masonry and appliances concentrate real weight. Our outdoor kitchen installation guide covers layout and utility planning; this article is specifically about what holds the structure up.

The slab-without-footings path

Most pergola kits and conventional patio covers are light enough that a slab alone can legally carry them — but “light enough” is a specific number, not a guess. The City of Dublin’s accessory-structures handout, which applies the patio-cover appendix of the 2025 California Residential Code, puts it this way:

“Structure may be supported on a minimum 3½-in thick concrete slab on grade without footings, provided the columns do not support loads in excess of 750-lbs per column (dead + live load).”

That 750-lb figure is per column, combining the structure’s own weight (dead load) with code-required wind and seismic loading (live load) — not just what the lumber weighs sitting still. A basic open-lattice pergola with light rafters is more likely to stay under that number per post; a heavy timber frame, a tile or metal roof that sheds water, built-in ceiling fans or lighting, or extra posts spaced far apart each push the per-column load up. The handout’s own plan checklist still asks for a foundation plan showing “type of foundation system” and, where used, “new footing details and reinforcement” — so even a slab-path project needs that number calculated and shown, not assumed.

When you need real footings

Several situations move a project out of the slab-only path, based on the same Dublin handout and the state residential code:

• Anything attached to the house. Dublin requires a building permit for “any structure attached to the main dwelling, regardless of size,” and an attached structure ties into the house’s own foundation design rather than standing on a simple slab.
• Size and height thresholds. Dublin requires a permit for any detached structure over 120 sq ft, and for any detached open shade structure over 1,000 sq ft or taller than 10 ft. Concord’s own permit bulletin lists patio covers and trellises as requiring a permit, with a narrow exemption for one-story detached accessory structures under 120 sq ft — and even then, a structure taller than 6 ft needs planning approval in Concord. Most real pergolas and outdoor-kitchen structures exceed these thresholds.
• Enclosed walls, not open lattice. The CRC’s patio-cover rules distinguish an open structure from one with enclosure walls, and an enclosed room changes both the load path and the egress rules.
• Masonry and heavy appliances. A stone-veneer kitchen island, a built-in pizza oven, or a stacked-stone bar counter adds real, concentrated dead load that a thin slab was not designed to carry at that one point — even when the shade structure overhead is light.

Once a footing is part of the design, the state residential code sets a floor on how deep it goes: “Exterior footings shall be placed not less than 12 inches below the undisturbed ground surface,” with further frost-protection requirements where they apply. The Bay Area’s mild winters rarely trigger the frost provisions, but the 12-inch minimum, plus any additional depth and width an engineer calculates for the actual load and soil, still applies.

Outdoor kitchens add a second question

Choosing the right base only answers the structural half of an outdoor kitchen. The utility half is separate, and it does not care which base you picked. The City of Concord’s permit bulletin lists gas piping (new or extension), water piping (new or extension) and new or extended 120V/240V wiring as always requiring a permit, new or replacement. Dublin’s handout makes the same point for accessory structures generally: “permits are required for any electrical, plumbing and mechanical work that is proposed,” even on a structure small enough to skip the building permit on its own.

In practice, that means a modest open pergola over pavers might need no building permit at all — but the moment you run a gas line to a built-in grill, plumb in a sink, or add a dedicated circuit for a fridge and lighting, those trades need their own permits and inspections regardless of the structure above them.

Two cities, two sets of numbers

As with most accessory-structure rules, the specifics come from each city’s own ordinance, not a single statewide number. Here is what two cities in our service area publish, checked October 2026:

The practical takeaway: a design that clears Dublin’s slab-only path on paper is not automatically fine in the next city over. Confirm both the structural threshold and the permit exemption with the building department for your specific address before you pour anything.

Steps before you pick a base

1. Step 1Total the load per postAsk your designer or contractor for the dead-plus-live load on each column, including roof material, wind and seismic — not just the frame’s weight.
2. Step 2Check attachment and enclosureAttached to the house, enclosed walls, or over a set floor area and height all change the answer, before load even enters the picture.
3. Step 3Separate the counter from the roofIf there is an outdoor kitchen, decide the foundation for the masonry island independently of the shade structure’s posts.
4. Step 4Call your own city, not a general answerDublin and Concord alone differ on thresholds; get your city’s current handout before assuming a slab-only design is exempt.

Questions homeowners ask

Related services and guides

• ServicePergola construction
• ServiceOutdoor kitchen installation
• ServiceConcrete patio installation
• ServicePaver installation
• GuideHow deep a paver base should be in Bay Area clay
• GuideRetaining wall permit rules in the Bay Area