Is a permit required?
Decatur requires a permit for a deck that is larger than 200 sq ft, more than 30 inches above grade, attached to the dwelling, or serving a required exit.
"Deck greater than 200sf, or 30" above grade, or attached to dwelling, or serve required exit"
Source: decaturil.gov
Decatur also requires a permit for a new or replaced stair or railing.
"Stair and/or railing replacement or addition"
Source: decaturil.gov
How to apply
Permits are requested online through the city's OpenGov platform.
"You can request a permit through the City of Decatur OpenGov platform"
Source: decaturil.gov
A homeowner can pull the permit only for work on the primary residence the owner owns and lives in.
"As a homeowner you may obtain a permit only if you are performing the work on your primary residence, which you own and reside in."
Source: decaturil.gov
What it costs
Residential building permit fees are 0.5% of project value, with a $50 minimum.
"Building permit fees in Decatur, Illinois are calculated as a percentage of project value: 0.5% for residential one- and two-family dwellings, minimum $50, and 0.75% for commercial, minimum $150."
Source: decaturil.gov
Footings and frost depth
Decatur's adopted residential code sets a frost line depth of 36 inches.
"Frost Line Depth, 36 inches"
Source: decaturil.gov
Inspections
Inspections are requested online through the permitting software.
"When ready for an inspection, request it online through our permitting software."
Source: decaturil.gov
Other rules
A deck that meets none of the four triggers (200 sq ft or less, 30 inches or less above grade, detached, not at a required exit) is not on the permit-required list, but the city tells owners to check first.
"If you are in doubt or have any questions, please Contact Us prior to starting any project to verify the need for a permit."
Source: decaturil.gov
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 Decatur. Rules change, and some neighborhoods and HOAs have their own. Confirm with the city before you build. Spotted something out of date? Tell us.