Zionsville BZA continues appeal over whether homeowner deck counts as impervious area

Property owner Tom Bennett appealed a staff determination that his recently-built deck counts against maximum lot coverage because the town's definition of "impervious" lists decks as an example. Appellant counsel argued the code language is ambiguous and urged the board to apply the principle that ambiguity in zoning definitions should be construed in favor of landowners. Staff said its historical practice counts decks toward lot coverage because the deck surface and materials substantially reduce infiltration compared with natural ground.

The board agreed to continue the appeal so the petitioner can provide certified engineering calculations and a drainage/performance analysis demonstrating whether the deck substantially reduces or prevents stormwater infiltration. The board and staff also agreed on a process: the petitioner will work with planning staff to identify the engineering qualifications and the scope of analysis that will satisfy the town's review; staff may seek independent review if necessary. The continuance allows the parties to resolve factual questions before the board makes a formal determination under the code's "substantially reduces or prevents" standard.

Appellant Tom Bennett read the ordinance text into the record during argument: "Impervious area shall include but is not limited to decks," which prompted legal discussion over whether that example can be read as an all‑inclusive rule or only an illustrative example. The board granted the continuance and asked that the petitioner return with engineering evidence and that staff identify minimum report standards.