Do I need a permit for deck construction or replacement in Unincorporated Miami County?

Most likely yes. Deck construction or replacement usually requires a permit in Indiana. Confirm the specifics with Unincorporated Miami County.

Indiana's residential code deletes the IRC's permit, exemption, inspection, and fee sections (R105 and R108 to R114), so whether this job needs a permit is set by the local ordinance of the city, town, or county, not by the model IRC exemption list. Decks follow Section R507 of the 2020 Indiana Residential Code; Indiana's R507.4.1 requires lateral restraint where posts bear on concrete footings, by manufactured connectors or at least 12 inches of post embedment in surrounding soils or concrete piers. IC 36-7-2.5 sets statewide rules for any city, town, or county that requires Class 2 permits: plan review must be completed within 7 business days after the unit confirms the application is complete, and the owner may use a qualified private provider for plan review or inspection. Before digging, the person responsible must notify the statewide one-call association at least two full working days before work begins (IC 8-1-26-16). This deck is attached to the house or will have a roof. Where a small deck exemption exists at all, it covers only small, low, freestanding decks that do not serve the home's required exit door, so an attached deck falls outside it. A ledger bolted to the house is the most common point of deck failure, which is why departments inspect the footings, framing and ledger connection before the decking goes on. Adding a roof makes the deck a covered structure that is reviewed like a patio cover or addition, including roof framing and, in high wind areas, uplift connections.