Quick one for the number nerds: in a typical office, does a 2.2 gpm-to-0.5 gpm aerator swap beat a 1.6 gpf-to-1.28 gpf toilet retrofit on total water saved? Using 20 s handwashes at about 800/day, I get about 450 gal/day saved on faucets versus about 190 gal/day on toilets — curious if your counts line up or if I’m overestimating wash frequency.
Your 800/day seems high; at 400–600, faucets still win; verify ‘2.2 gpm’ at your actual pressure.
It sounds like you’ve run the numbers well, but don’t forget to check your water pressure; that ‘2.2 gpm’ could be off if it varies. I had a similar issue once, and switching to a low-flow faucet made a noticeable difference in our overall usage. Curious if you’ve tried adjusting the pressure settings?