Bathroom Aerator Flow Rate
Average measured flow rate of all bathroom faucet aerators.
Spec by tier
This requirement steps in stringency by tier. Each tier inherits and tightens the value.
Scope
Aerators on every bathroom lavatory (sink) faucet in the dwelling. Kitchen, utility, and laundry-sink aerators are excluded.
Requirements
Performance targets
- 01.
Measure or read the rated flow rate (GPM) of every bathroom faucet aerator in the home.
- 02.
Calculate the average GPM across all bathroom aerators; the average must meet the tier threshold in the "Spec by tier" table.
- 03.
Alternative pathway: submit a Home Water Score report meeting the tier threshold in lieu of per-fixture measurement.
Documentation
Evidence the inspector / Institute will need.
- 01.
Photo of each bathroom aerator showing the stamped GPM rating (typically printed on the underside or on the packaging).
- 02.
OR field flow-test record (date, location, measured GPM, signature) for each aerator.
- 03.
OR a Home Water Score report referencing the dwelling.
Guidance
How to read an aerator
Bathroom aerators are stamped with their flow rate in tiny letters on the underside, on the side ring, or on the original packaging. The most common ratings are 0.5, 1.0, 1.5, 2.0, and 2.2 GPM. WaterSense-labeled aerators max out at 1.5 GPM and produce noticeably softer spray.
Swapping a non-compliant aerator
Most aerators swap in under a minute with no tools:
- 01.
Unscrew
Unscrew the existing aerator by hand (counterclockwise as you look up at it). If it is stuck, wrap with a rag and use slip-joint pliers gently.
- 02.
Match thread
Bathroom aerators come in male (M22 or M24) and female (M22x1) thread. Bring the old one to the store to match.
- 03.
Install
Hand-tighten the replacement with the included washer. No tools or thread tape required.
- 04.
Test
Run full flow for 10 seconds and re-measure to confirm.
Resources
- EPA WaterSense — Bathroom Faucets →
1.5 GPM federal high-efficiency spec, with optional 0.8 GPM tier.
Note
For Platinum, the 0.5 GPM target is aggressive but workable in bathrooms (faucets are used mostly for short hand-washing bursts). Kitchen faucets generally cannot run that low and are not covered by this requirement.