Permit Fee Calculator
Estimate your Mill Valley building permit fees, with every formula shown. An estimate — not an official City invoice.
Step 1
Your project
Default $616 is inferred from one invoice — not a verified citywide rate. Replace with the City's figure if you have it.
If the City gave you a valuation, enter it to use it directly for Scenario A.
Step 2
Additional fees
Document processing & storage
Official invoices may differ by a cent depending on rounding.
Estimated total permit fees
$6,544.11
on a valuation of $99,792
Basic permit fee
$2,159.50
% of build cost
16.4%
Per sq ft
$40.40
Comparison
Standardized vs. your estimate
Scenario A
162 sq ft × $616
$6,544.11
valuation $99,792
Scenario B
Your estimated cost
$3,748.17
valuation $40,000
Difference: $2,795.94 more under the standardized valuation (valuation gap $59,792).
Illustrative only. The City is not required to accept a homeowner's valuation.
Scenario A
Itemized fees
Export
Save & share
Invoice check
Compare with your City invoice
Calculations use the fee toggles and amounts you set above. Sample invoice valuation ($99,792) is inferred from its road impact fee.
Invoice total
Sum of entered lines
$0.00
Calculated total
$1,073.00
Differences are flagged, not labelled errors. They can come from cent rounding, fixed fees, a different valuation, or an alternate calculation method the City uses.
Explainer
How Mill Valley calculates your fees
An assigned valuation
The City has stated that it uses standardized construction costs per square foot for different project categories to determine an assigned valuation.
The basic permit fee
That assigned valuation appears to feed into the published valuation-based building permit fee schedule (July 1, 2026).
Fees built on top
Many additional fees are then calculated as percentages of either the basic permit fee or the assigned valuation.
The standardized rates and classification rules have not been independently verified. The $616/sq ft default is inferred from one invoice and is not an officially adopted rate.
Published basic fee schedule
Estimates only — not an official City of Mill Valley invoice. Calculations are deterministic and based on the July 1, 2026 published schedule plus the assumptions you enter. Confirm all fees with the City's Building Division.