What matters for project planning
The land-disturbing provision is the one that reaches a deck. Naperville is the permitting authority for land-disturbing activity, and footing excavation is exactly the kind of ground disturbance that framework exists to govern — which makes it a question to settle before a design rather than after. If the deck sits within the portion of the city inside DuPage County, the floodplain regulations Naperville has adopted can also reach whether a structure may be placed at a given location. On-site stormwater control facilities matter here too: a deck and any hardscape beneath it change how the lot sheds water into the routes the city's plan depends on.
Official sources
Verify the property, not just the city
Citywide context cannot establish a parcel’s flood zone, historic designation, stream buffer, permit requirements, soil conditions, or concealed construction. Confirm those items with the appropriate authority and selected provider before work begins.
Sources reviewed 2026-07-26. External requirements and maps can change.