Raised Deck Ideas for Boise-Area Homes

What makes a raised deck work in the Boise area?

A raised deck earns its height. It levels a sloping yard, puts the floor even with the back door, and lifts the view over a fence. The same height brings guards, stairs, deeper bracing and a permit, so the best designs decide where the stairs land, what the railing looks like and what happens under the deck before anyone picks a board color. The ideas below are design examples for decks roughly 1 to 6 feet above grade, the common composite deck off a back door.

Do raised decks need a permit in Boise, Nampa and Meridian?

Almost always. Boise requires a permit once a deck or concrete patio is more than 12 inches above grade, which is stricter than the 30-inch figure in the model code. Nampa uses the same 12-inch threshold. Meridian requires one for any deck attached to the house, any deck serving an exit door and any deck over 200 square feet. A raised deck off a back door clears all of those.

Eagle's published checklist asks for the deck location and the construction and ledger-connection details, and we did not find a published low-deck exemption, so plan on a permit there too. Star's threshold is 30 inches. Boise also asks for stamped engineering on decks more than 6 feet above grade, which is why 6 feet is a natural dividing line in this guide. The Boise deck permit guide, Nampa deck permit guide and Meridian deck permit guide list what each city asks you to submit. Homes in an HOA usually need design approval, which our HOA deck approval guide covers.

Where should the stairs go?

Put them where people already walk: toward the gate, the side yard or the lawn, not wherever the framing is easiest. Stairs eat yard. Each foot of height needs about 15 inches of run at code-limit risers and treads, so a 4-foot deck can push a stair 5 feet or more into the yard. Draw the footprint on the lot before settling on the deck size.

The 2018 IRC as adopted in Idaho limits risers to 7¾ inches and requires treads of at least 10 inches, with no more than ⅜ inch of variation between steps. Stairs must be 36 inches wide, and a handrail set 34 to 38 inches high is required once a flight has four or more risers. Three layouts suit raised decks:

• Straight run along one side: the simplest and cheapest, and it keeps the stair out of the middle of the deck edge.
• Wide stair across a short side: 6 to 8 feet of width reads as part of the deck and doubles as seating, with a handrail on each side.
• Stair with a landing: a landing breaks a tall run into two flights, turns the stair along the house, and gives a safe stopping point for a 5- or 6-foot drop.

Whichever layout you pick, the stair needs a solid landing at the bottom, such as a paver pad or concrete, so the lowest tread does not sit on soil that heaves or washes out. Our deck railings and stairs service covers stair and rail work on new and existing decks.

Which railing style suits a raised deck?

A guard is required wherever the walking surface is more than 30 inches above the grade below. The IRC calls for a minimum 36-inch height on the deck, 34 inches on stair sides, and openings that will not pass a 4-inch sphere. The AWC's DCA 6 guide calls for guard posts that resist guard-post connections with hold-downs rated for 1,800 pounds, so a post fastened only to the rim board is not a compliant detail. Style is your choice within those limits.

Compare finishes and costs in the deck railing options guide. On a deck 4 feet or higher, the rail is the first thing seen from the yard, so it deserves as much design time as the boards.

Footings, frost depth and the ledger

Raised decks sit on concrete footings that extend below the frost line, which Boise's adopted design criteria set at 24 inches. NOAA's 1991–2020 normals count 108 nights a year at or below 32°F at the Boise airport, so the freeze-thaw cycle is real. A footing that stops short of the frost line can lift in winter and drop in spring, which racks stairs and pulls on the ledger. The deck footing depth guide walks through footing sizes.

The ledger is the board that ties the deck to the house, and it carries a large share of the load. The IRC does not allow a ledger to attach through masonry veneer, so a brick or stone-faced back wall changes the design. Flashing is the other half: water that gets behind a ledger rots the house framing, not just the deck. Ask how the ledger will be fastened, flashed and inspected. Boise's checklist asks for the ledger connection details at permit time. If the ledger cannot attach to the wall, a free-standing deck with its own beam and posts next to the house is the usual fix.

How much snow can a raised deck carry?

More than Boise gets. The IRC sizes the deck for a 40 psf live load, and Boise's ground snow load is 20 psf. The AWC's DCA 6 guide excludes decks where snow load exceeds 40 psf and excludes hot tubs. Raised decks under a roof, or beside a taller roof that sheds snow onto them, need separate design; see the deck snow load guide. Keep stairs and the top of the guard cleared in winter, because ice on a raised stair is the real snow hazard.

Built-in benches and planters

On a raised deck, a bench along the edge can replace part of the guard run, but only if it is engineered as a guard. Seat height is lower than 36 inches, so a bench without a rail behind it does not meet the guard height. The simpler idea is a bench set back from the edge or against the house wall, with storage underneath for cushions.

Planters work the same way. A built-in planter box adds weight, and soil is heavy when wet, so plan joist or blocking support below it. Line it, drain it away from the framing, and keep the planter off the ledger area. Many raised decks use a freestanding planter on the surface instead.

Lighting, sun and July heat

Low-voltage step lights, post-cap lights and under-rail strips light the stair and edges without a spotlight look. In Boise, low-voltage outdoor lighting does not need an electrical permit; 110-volt work does. Run the wire before the decking goes down.

Heat deserves a layout decision too. NOAA's normals put Boise's average July high at 92.7°F, with about 55 days a year at 90°F or above and about 9 at 100°F or higher. Dark composite boards run hot underfoot in that sun. A raised deck is more exposed to sun and wind than a ground-level patio in most yards, so consider lighter board colors on the south and west sides, a shade structure, or a covered deck or pergola. The decking for full sun guide compares boards, and the composite decks service covers the material.

What goes under a raised deck?

Skirting hides the framing and keeps animals out. Use lattice, composite slats or horizontal boards with gaps, and leave ventilation so the framing dries. Under a deck 5 or 6 feet high, a gated access panel gives you a place to retrieve things and check the footings.

The space under a deck can also be dry storage or a patio. Under-deck drainage systems catch water between the joists and send it to a gutter, which makes the lower space usable but adds cost, and they should be planned with the framing, not retrofitted. In Boise's wildland-urban interface overlay, the city's checklist refers to protected underfloor areas, so check with the building division before closing in or storing anything flammable under a deck in the Foothills. The wildfire-resistant decking guide has the details.

Privacy and sightlines

A deck 4 to 6 feet up looks into neighbors' windows and yards, and they look back. Privacy screens on the exposed side, slatted panels, tall planters or a pergola wall are easier to include in the first drawing than to add after an HOA complaint. Keep screens clear of the sight line from the back door to the yard, and mind the sun: a tall screen on the south side shades the table you are trying to use. On a view deck, put the solid screen on the neighbor side and keep the view side to cable or glass.

How does height change the cost of a deck?

Height drives framing, bracing, footings, stairs and railing, so it changes the price more than a few extra board feet would. The cost model behind the deck cost calculator applies a 0.9 multiplier at ground level (under 12 inches), 1.0 for a raised deck of 1 to 4 feet and 1.3 for a second-story deck of 8 feet or more. It has no separate value for 4 to 8 feet, so decks in that range need a measured quote. These are published market ranges adapted from Iron Crest Remodel's Boise pricing and HomeGuide benchmarks, not Valley Decks quotes.

Railing, stairs, demolition, covers and lighting are priced separately and are not in those numbers. The composite deck cost guide breaks the pieces out, and the Boise deck cost guide covers the local factors. Use the calculator for your own size.

What to ask any builder about a raised deck

• Is the permit included, and who pulls it? Which inspections will be scheduled?
• How deep are the footings, and how are the posts connected to them?
• How is the ledger attached and flashed, and what happens if the wall is brick?
• What does the stair rise and run work out to, and where does it land?
• Which guard system is proposed, and what is its post connection?
• Is there skirting, and how will the framing ventilate?
• What is excluded from the price: demolition, lighting, railing, stairs?
• Will they send a written scope after an on-site measure?

Bring the answers to a site visit. If you want a Valley Decks measure for a raised deck, request an estimate. For decks that step down a slope, see the multi-level deck ideas, and for a hot tub on a raised frame, the hot tub deck ideas.