Check this with the city: Springfield's deck plan form dates from about 2009 and its inspection sheet from 2016. The 36-inch frost depth is from the current city code. Confirm the rest with the city.
Is a permit required?
Springfield's code lists the work exempt from a building permit (small sheds, low fences, low stoops and slabs and a few others). Decks are not on the list, so a deck needs a permit; only stoops or slabs 30 inches or less above grade with no roof are exempt.
"Stoops, or slabs with no roof covering and driveways not more than 30 inches above grade and not over any basement or story below."
Source: library.municode.com
Springfield charges a penalty fee of $300 or the permit fee, whichever is greater, when work starts without a required permit.
"a fee of either $300 or an amount equal to the permit fee, whichever is greater, shall be assessed."
Source: library.municode.com
What to bring
The city's Deck Plan form asks for deck length and width, joist, beam and post sizes, footing depth and deck height above grade.
"Column (post) size Depth of footings below grade Height of deck above grade"
Source: springfield.il.us
Footings and frost depth
On the city Deck Plan form, a deck attached to the house needs column footings extending at least 36 inches below grade.
"column footings are required for the deck, and the footings must extend a minimum of 36" below grade."
Source: springfield.il.us
Springfield's local amendment to the International Residential Code sets the frost line depth at 36 inches.
"FROST LINE DEPTH 36""
Source: library.municode.com
Railings and guards
The Springfield Deck Plan form requires guardrails at least 36 inches high on porches and balconies more than 30 inches above grade.
"Porches and balconies located more than 30" above grade must have guardrails"
Source: springfield.il.us
Inspections
Springfield inspects footings before they are poured.
"Footings must be inspected prior to pouring."
Source: springfield.il.us
Inspections are requested by phone with the address, type of inspection and ready time.
"Contact (217) 789-2171 for inspection request."
Source: springfield.il.us
Before anyone digs
Illinois law requires a call to JULIE, the state's one-call system, before digging deck footings. Call 811 or (800) 892-0123, or file online, at least 3 days before work starts. The call is free, and the locate is good for 25 days. On a hired job, the company doing the digging makes the call. More on Illinois deck rules
We are not the City of Springfield. Rules change, and some neighborhoods and HOAs have their own. Confirm with the city before you build. Spotted something out of date? Tell us.