0.35, not 35: reading CALGreen's WS-2 water-use worksheet

Open CALGreen's water-use reduction worksheet — WS-2 — and one number in the fine print never made sense. Footnote 4 called for a fixture flow rate of 35 gpm. The January 2026 errata corrects it to 0.35 gpm. That's a 100x move, and on this particular form it isn't a harmless typo.

Here's the thing: 35 gallons a minute isn't a faucet. A nonresidential lavatory faucet in California maxes out at 0.5 gpm at 60 psi. Thirty-five is seventy times that — hose territory, not handwashing. On a worksheet whose entire job is to prove you used less water, a number that high doesn't just look wrong; it breaks the math underneath the credit.

Let me walk through how WS-2 actually works, and why the decimal point matters.

What WS-2 is for

CALGreen's water-efficiency path runs on two worksheets. WS-1 establishes your baseline — the code-maximum flow and flush rates for the fixtures in the building. WS-2, Water Use Reduction, is where you show the design beats that baseline by the required percentage.

The reduction is measured against the code maximums, not against whatever a manufacturer's cut sheet claims. CALGreen is explicit that the reduction "shall be based on the maximum allowable water use per plumbing fixture and fitting as required by the California Building Standards Code." You can demonstrate it two ways: a prescriptive method — every fixture meets a published reduced flow rate — or a performance method, a calculation showing the whole-building baseline drops by the target percentage.

That's why a stray "35 gpm" in a footnote is corrosive. The worksheet is a percentage engine: baseline in, reduced design in, savings out. Feed it a flow rate seventy times the legal maximum and the percentage inverts — you can't "reduce" to a number that's higher than where you started.

The number it should have been: 0.35 gpm

0.35 gpm isn't arbitrary. It's the low-flow lavatory rate CALGreen already publishes in its own reduction table.

Verified against CALGreen Table A5.303.2.3.1 (Fixture Flow Rates, Prescriptive Method): nonresidential lavatory faucets carry a baseline of 0.5 gpm @ 60 psi and a maximum of 0.35 gpm @ 60 psi at a 12-percent reduction. The same table's footnote adds: "Where complying faucets are unavailable, aerators rated at 0.35 gpm or other means may be used to achieve reduction."

So the corrected value lands exactly on a rate the code already carries — a 0.35-gpm aerator on a lavatory faucet, the standard move for squeezing reduction credit out of a fixture that already sits at the 0.5-gpm mandatory floor. The errata didn't invent a number. It put the decimal point back.

The flow rates worth memorizing

Most WS-2 confusion isn't the typo — it's mixing up which lavatory rate applies where. The verified CALGreen maximums:

Fixture	Max flow	Section
Residential lavatory faucet	1.2 gpm @ 60 psi	§4.303.1.4.1
Lavatory in residential common/public areas	0.5 gpm @ 60 psi	§4.303.1.4.2
Nonresidential lavatory faucet	0.5 gpm @ 60 psi	§5.303.3.4.1
Nonresidential lavatory at 12% reduction	0.35 gpm @ 60 psi	Table A5.303.2.3.1

Read it top to bottom and the logic is clean. A private residential lavatory is allowed 1.2 gpm; put that same fixture in a common or public restroom and it drops to 0.5; a nonresidential lavatory starts at 0.5; and to earn reduction credit you take it to 0.35. The corrected footnote sits at the bottom of that ladder, not seventy rungs above the top of it.

One note on the residential side: §4.303.1.4.1 also sets a minimum — residential lavatory faucets can't flow below 0.8 gpm at 20 psi — so "low-flow" has a floor, too.

Filling it out without inheriting the typo

• Check your printing. If your CALGreen copy predates the January 2026 buff-page errata, Footnote 4 still reads 35 gpm. Confirm the corrected 0.35 before you cite the worksheet.
• Reduce against the code maximum, not the catalog. WS-2 percentages are measured off the §4.303 and §5.303 maximums, not the product's rated flow.
• Match the lavatory rate to the occupancy. Residential, residential common/public, and nonresidential lavatories don't share a number — and that's the more common WS-2 error than the famous typo.
• When in doubt, confirm the current worksheet and rates with your local jurisdiction. They're reviewing against the corrected printing.

What CrossBeam does with it

CrossBeam reads plans against the current code text — the WS-2 with 0.35 gpm in Footnote 4, not the first printing's 35. So a water-efficiency submittal gets measured against the flow rates the code actually requires today, with the right lavatory maximum applied to the right occupancy.