Boise, ID Deck Permit Rules (2026)

When does a Boise deck need a permit?

Measure from the ground to the walking surface. If any part of the deck is more than 12 inches up, Boise wants a building permit. The rule appears in both the city's residential construction brochure and its online Homeowner's Guide, and it applies to wood decks and raised concrete patios alike.

That 12-inch line is where Boise parts ways with the model code. The 2018 IRC's permit exemption lets a detached deck skip the permit if it stays under 200 square feet, never rises more than 30 inches above grade and doesn't serve the required exit door. Boise does not use that exemption for decks, so a 150 sq ft platform at 20 inches is permit work here even though it would be exempt in a city that kept the model language.

If a cover is part of the plan, the cover drives the permit regardless of deck height. Our covered decks and pergolas page walks through the structural side of that work.

What goes in a Boise deck permit application?

Boise reviews decks on its #406 Residential Addition, Alteration & Accessory Building checklist. The July 2025 version has its own deck section, and it is specific about what the drawings must show:

1. A site plan locating the existing house, any accessory buildings and the new deck, with dimensions to property lines and other buildings.
2. A framing plan at about ¼ inch = 1 foot showing every footing and post, plus the size, spacing, span and direction of all joists, beams and connectors.
3. Elevations of each side of the deck showing its height, how it attaches to the house, and guardrail height and member spacing when the deck is more than 30 inches up.
4. Section views from the bottom of the footing through the deck and rail: footing size and depth, post-to-footing, beam-to-post and joist-to-ledger connections, the connection to the house, and the decking material. Stairs get their own section.
5. Stamped structural calculations for any deck taller than 6 feet or any design the IRC doesn't cover.

Sheets must be at least 11 × 17 inches. You can apply online or book an in-person appointment with a plans examiner. Footing depth is the line item that most often gets red-marked; Boise's adopted frost depth is 24 inches, and our deck footing depth guide covers sizing by load and soil.

Boise deck inspections

You schedule inspections through the city's online permitting system or by calling the permit counter at 208-608-7070. Boise's cutoff for both morning and afternoon inspection slots is 7:30 a.m., and the city-approved plans must be on site when the inspector arrives.

Boise's published inspection list is written for houses and additions rather than decks, but its footing inspection language carries over: piers excavated and forms in place before any concrete is poured. Third-party permit guides describe the usual deck sequence as footing, framing and final; treat that as typical rather than guaranteed and follow the inspection list printed on your permit. The framing visit matters because ledger bolts, joist hangers and flashing disappear once decking goes down.

Historic districts, hillsides and the WUI: Boise's extra layers

Historic districts

Boise's Certificate of Appropriateness list names "constructing an addition, porch, or deck" as work that needs a C of A when the home is in a historic district, and the certificate must be in hand before you apply for the building permit. Minor projects are reviewed by staff in 15 days, followed by a 10-day appeal period; bigger changes go to a public hearing. Owners in the North End should check the city's Decision Matrix before drawing anything.

Hillside overlay

The Hillside Development Overlay (HS-O) applies where slope exceeds 15 percent or where soils, springs or erosion raise stability concerns. The city lists exterior additions to existing structures among its Category 2 examples, the #406 checklist requires a Hillside Questionnaire for every property inside the overlay, and footings there need stamped engineering.

Wildland Urban Interface

Foothills lots generally north and west of Hill Road fall in the IR1 zone, which requires Class 1 ignition-resistant construction. When a project sits in the WUI, the #406 checklist asks the drawings to show fire-resistive elements, including "decks constructed of appropriate materials" and protected underfloor areas. Which deck materials qualify on your lot is a Boise Fire question; our wildfire-resistant decking guide covers the options and listings to ask about.

Does your HOA have to approve it too?

Usually, and the city won't check for you: HOA approval is not a line item on Boise's #406 checklist. Get the architectural committee's sign-off in writing before you build, and build what they approved. The Idaho Supreme Court's 2019 Eagle Springs decision, which involved a Boise subdivision, upheld an HOA's injunction against an owner whose project went past its approval. Our HOA deck approval guide explains the paperwork.

How long does a Boise deck permit take?

The #406 checklist says online applications are typically reviewed within two weeks. Simple in-person submittals can be processed in about an hour; incomplete or complex ones are held for later review, typically within two weeks. Stack the extra layers on top: a staff-level historic certificate adds at least 15 days of review plus the 10-day appeal window, and HOA committees set their own pace. Third-party permit services put HOA review at one to six weeks. For a spring deck, that math is why our build-timing guide pushes design into late winter.

Owner-builder permits in Boise

Yes. Boise's brochure says homeowners may work on their primary residence without registering as a contractor, provided they pull the permit and do the work themselves. Anyone else doing part of the job, an electrician running a line-voltage circuit for lights for example, must hold the matching Idaho license. The city also encourages owner-builders to request a conference with the inspector before starting. If you'd rather hand off the drawings, permit and build, request an estimate and we'll measure the site.