How does the Indiana Building Code affect my remodel?

Indianapolis remodels run under the Indiana Building Code, which is adopted at 675 IAC 13 (commercial / IBC) and 675 IAC 14 (residential / IRC) by the Indiana Department of Homeland Security Division of Fire and Building Safety. The current cycle adopts the 2020 IRC, 2020 IBC, 2020 IECC, and 2020 IFGC with Indiana-specific amendments. Marion County and the City of Indianapolis ratify the state code without significant residential carve-outs, so what passes in Lawrence or Speedway is the same baseline that passes downtown.

Indianapolis sits in IECC Climate Zone 5A (cool / humid). For a remodel that opens up envelope, that drives a few hard numbers worth pricing into your scope. Ceiling insulation: R-49 minimum for new ceilings, R-38 if you are working in cathedral ceilings with full-depth insulation against the deck. Walls: R-20 cavity insulation, or R-13 cavity plus R-5 continuous exterior, or R-0 + R-15 continuous (cavity-free). Floors over unconditioned space: R-30. Basement walls: R-15 continuous or R-19 cavity. Slab edge: R-10 to 2 ft below grade. Windows: U-factor at or below 0.30, SHGC at or below 0.40 (south-facing exemption available with overhang).

You do not have to bring an entire 1920s bungalow up to 2020 envelope just because you are remodeling a kitchen -- IRC Chapter 11 / IECC R501.1.1 only triggers full envelope upgrades when you reframe walls or replace exterior wall insulation. Like-for-like work and interior-only remodels generally keep their existing assemblies. But if you are gutting to studs, the inspector will look for the new R-values.

Mechanical and plumbing follow Indiana's 2014 Mechanical Code and 675 IAC 16 (UPC) -- same enforcement, same Indianapolis DBNS permit. HERS testing or visual inspection of duct sealing is required on additions and major reroofs that disturb attic ducts.

Baily can pull the right code section for any specific scope you are planning -- ask in chat with your address and what you are touching.