Garden City, ID Deck Permit Rules (2026)

Does a Garden City deck need a permit?

Assume yes until Building Services tells you otherwise. Garden City's April 2023 residential application lists "Deck (uncovered)" as a project type, and it asks for uncovered deck square footage separately from covered porch and deck area. The city treats a deck as its own permit, not as an afterthought to a house.

What we could not confirm is the exemption. The applications page says work exempt from permit is defined in Garden City Code 7-2-3 F, the city's amendment of IRC section R105.2. That code text wasn't retrievable from the city's code host when we checked on October 15, 2026, so we won't guess at a number. The model IRC exempts a detached deck of 200 square feet or less, no more than 30 inches above grade, that doesn't serve the required exit door, but Garden City amended that section and we don't know how. Call Building Services at (208) 472-2921 with your deck's size, height and attachment.

Two lines the city does publish are on its minor-work floodplain form: one-story detached accessory structures over 200 square feet need a residential building permit, and so do fences over 7 feet. Both are written for sheds and fences, and neither tells you where a deck falls.

Garden City is surrounded by Boise and Eagle, so owners often read Boise's 12-inch rule and assume it applies. It doesn't; Garden City issues its own permits.

Who reviews and inspects a Garden City deck permit?

You file with the city, and contractors do the review. Garden City says permits are still submitted through the city for routing and a complete plan review, and that it contracts with SAFEbuilt and the Idaho Division of Occupational and Professional Licenses for plan review and inspections. Mechanical, electrical and plumbing permits go directly to the state, so a line-voltage circuit for deck lights or a hot tub is a separate state permit.

• Submit at City Hall, 6015 N Glenwood St, or by email to building@gardencityidaho.org.
• Building Services: (208) 472-2921. Inspection hotline: (208) 472-2920.
• Counter hours are short: 9 to 3:30 Monday and Friday, 10:30 to 3:30 Tuesday and Thursday, 9 to noon Wednesday, closed noon to 1.
• Incomplete applications are not accepted, so the first submittal has to be the whole package.
• State-licensed trades, such as the electrician wiring deck lights, must show their Idaho certificate of competency before a permit issues, and inspectors may ask to see the card on site.

What goes in a Garden City deck application?

More paperwork than most Treasure Valley cities ask for. From the residential application and its required checklist:

1. The full residential application, all pages, plus an electronic copy of every plan sheet labeled with a description.
2. The signed plan checklist, completed by the design professional of record or by the applicant when no designer is required.
3. An Affidavit of Legal Interest signed by the owner and notarized, even when the owner is the applicant.
4. The Flood Risk Acknowledgement, listed on the checklist with an original copy submitted to the city.
5. An Erosion and Sediment Control application if the work disturbs land.
6. An elevation certificate if the property is in the floodplain or floodway.
7. A lead certification number if the home was built before 1978.

The site plan must show decks with setbacks to property lines, with bearings and distances matching the recorded plat, plus easements, the floodway and 100-year floodplain, fences and outdoor lighting with its shielding. A landscape plan, which can sit on the site plan, shows rivers, drainages, irrigation canals, ditches and laterals. Plans must be scaled at 1 inch = 20 feet or ⅛ inch = 1 foot or larger. The foundation plan calls for every footing and pier size and the column-to-footing connectors, and the stair section shows treads, risers, headroom, handrails and guards. The checklist also lists an ACHD impact-fee receipt, or ACHD's confirmation that none is due, before the permit issues.

Which design numbers go on Garden City drawings?

Your own, stated on the plans. Since March 31, 2016, Garden City has required every plan set to include the design criteria used, and plans without them won't be approved. The application prints a sample block labeled "EXAMPLE ONLY": 2018 IRC, 24-inch frost depth, 40 psf floor live load, 1,500 psf soil bearing, 25 psf roof snow and 90 mph basic wind speed. Treat those as the city's illustration, not a published table, and have the designer confirm the values for your lot. Our deck footing depth guide covers footing sizing once the bearing value is set.

How does the floodplain affect a Garden City deck?

It's the first thing to check here. The city estimates 74 percent of its properties are in the 100-year floodplain and roughly 1,700 are in the regulatory floodplain. The regulatory maps are still the 2003 ones: FEMA's June 2020 Lower Boise River maps placed Garden City in seclusion while the city studies certifying its levees. The residential application asks whether the project is in the floodplain and whether an elevation certificate is attached.

A separate Floodplain/Floodway Development Application is required for fill or grading in the floodplain, any work in the floodway or river channel, work in the riparian area, and removing or damaging vegetation within 25 feet of the river. Each review cycle can take up to 15 working days. The city's minor-work floodplain permit covers sheds under 200 square feet and $7,500, parked RVs and fences; decks aren't on that list. Whether a deck's footing holes count as grading is a question for floodplain@gardencityidaho.org before you draw.

The Flood Risk Acknowledgement is written for owners of new buildings that sit outside today's mapped floodplain but inside the city's model of the future one. It's notarized and recorded, and it states that building to the model's flood elevation is strongly recommended but not required. For a deck, open framing and boards that tolerate getting wet are the sensible response.

What changes for a manufactured home or a pre-1978 house?

Garden City's plan checklist requires engineer-stamped plans for every alteration to a manufactured home. A deck fastened to the home's frame can bring that requirement into a small job, so a freestanding deck or landing on its own footings, set just off the home, is the usual route. On a site-built home from before 1978, the application asks for a lead certification number, because cutting siding for a ledger disturbs old paint.

How long does a Garden City deck permit take?

Garden City doesn't publish a plan review time for SAFEbuilt, so ask at submittal. If a Floodplain/Floodway Development Application applies, add up to 15 working days for each review cycle. Townhome and planned developments often have an HOA; where one exists, get written approval before you submit, and our HOA approval guide covers the packet. For a replacement near the river, see our Garden City deck replacement page, the Garden City deck builder page, or request an estimate.