How are permits priced for indoor rainwater reuse?

I wouldn’t assume the building department is always the permit issuer; it may direct plumbing applications to a separate authority. For a useful estimate, describe the rainwater source and storage, treatment, indoor fixtures, and any connection to the potable plumbing, then ask which plan reviews and inspections apply and whether each has a separate fee. That should give you a more meaningful itemized estimate than asking for one “rainwater system” permit price.

The fee schedule is the key to whether indoor use raises the permit fee itself or adds separate charges. Some schedules use a flat fee, others base it partly on project valuation, and some list plan reviews and inspections individually. Indoor fixtures could mean extra line items, but whether they do depends on the local schedule.

Could you check whether the fee schedule lists backflow-device review or testing as a separate charge? If it does, that’s a distinct line item to budget for; if it’s covered under the plumbing permit or a general inspection, it may affect what gets reviewed without adding a separate fee.

Ask specifically whether indoor nonpotable lines need a rough-in inspection before they’re concealed. If so, the estimate should include that inspection, whether it’s billed separately or added under the plumbing permit, and the work needs to stay accessible until it’s done.