HawaiiDeck Code & Footing Depth
In Hawaii, deck footings must bear at least 12" below grade to sit below the frost line and resist heave. The calculator below is preset to that depth — size your joists, beam, posts and stairs to the IRC R507 deck code, then adjust for your build.
Member sizes read from the IRC R507.6 (joists) and R507.5 (beams) tables for No. 2 Southern Pineat 40 psf live + 10 psf dead. Footings from tributary load ÷ soil bearing (R507.3); ledger fasteners per R507.9. Confirm with your local building department.
| Decking — Pressure-treated pine192 sq ft · ~28 × 16′ boards | $575–$1,730 |
| Substructure (joists, beam, posts, hardware)192 sq ft framing | $1,150–$2,495 |
| Footings (concrete piers)4 posts | $140–$360 |
| Railing / guard40 lin ft | $600–$2,400 |
| Stairs4 treads | $120–$380 |
| Permit + fasteners + miscallowance | $75–$500 |
| Total estimate | $2,660–$7,865 |
Low = DIY material budget; high = contractor-installed (labor included). Regional prices vary — treat as a planning range, not a quote.
Building a deck in Hawaii
Most Hawaii jurisdictions adopt the International Residential Code, so the joist and beam span tables here apply statewide — but footing depth, snow load and local amendments are set by your city or county. The 12" depth shown is typical for Hawaii; confirm the exact figure with your building department before you dig, as it varies with elevation and soil.
You'll almost certainly need a permit for a deck attached to the house or more than about 30" above grade, plus a footing inspection before concrete is poured. A DeckCalc HQ Pro plan packages these numbers into a permit-ready PDF for your Hawaii submittal.