On pairing sinks with faucets: a study in usability

Dear people who choose sink-faucet combinations,

I have a bone to pick with you.

If good design is design you don't notice,

bad design is design you can't help but notice.

Design that runs counter to your goals.

Consider sinks..

I often come across combinations of sinks and faucets that infuriate me when my hands are forced to bump into the bottom or the back of the sink. This is almost always because there isn't enough clearance between where the water comes out of the faucet and the bottom of the sink basin (let's call this the "vertical gap") or between where the water comes out and the back rim of the sink basin (let's call this the "rim gap"). Sinks occasionally have insufficient rim gaps on the sides too, but an insufficient rim gap between the spout and the back of the basin is by far the most common problem with sink-faucet pairings.

Check out the example below.

The sink itself is sufficiently large but the faucet barely protrudes forward into the sink basin. It's also quite a low faucet. As a result, either A) the water only hits the ends of my fingers, or B) my hands bump the back of the sink in an attempt to get water onto my palms. Neither option feels good, which is why this sink-faucet pairing is, unfortunately, a failure.

This isn't even a particularly egregious combination. I've seen much much worse.

I have large hands.. but by no means am I an NBA player. My hands should never have to touch the sink basin. Heck, NBA players' hands shouldn't either.

Is this a huge problem?

Not really, no..

but it's so easy to avoid in the first place that I think we should fix it once and for all. Here's how:

Just make sure your sink-faucet pairing creates generous vertical and rim gaps so that the great majority of people can wash their hands without touching the sink.

Let's say the 99th percentile hand length in the US is 8 inches.

And let's say the 99th percentile hand width is 6 inches. This could also be called "height" when one's hands are held palm to palm in typical hand-washing orientation.

And let's say we want the water from a faucet to fall roughly into the middle or lower, lengthwise, of your hands when washing them, meaning somewhere around the top of your palm rather than high up on your fingertips.

Unless you are designing a sink for an extremely constrained space like an airplane or an RV, the solution is very simple. I propose the following two laws for harmonious sink-faucet pairings:

1. Make sure the back-to-front gap between the back of the sink's drainage area and where the water comes out of the faucet, as seen from above, is at least 5 inches,

4 inches being half the length of a large hand, plus an additional inch of space so that your hands never touch the back of the sink.

2. Make sure the vertical gap between the bottom of the sink basin and where the water comes out of the faucet is at least 7 inches,

6 inches being the full thumb-to-pinky width/height of a large hand, plus an additional inch of space so that your hands never touch the bottom of the sink while washing them.

Here are six more sink-faucet pairing examples that I've spotted in the wild and graded based on the above laws to further illustrate my point. Note that the usability of faucet controls is neither evaluated nor discussed in depth here. Faucet and shower controls likely merit a separate blog and are out of scope for the point I'm making here.

This sink has a glorious amount of room between the faucet spout and both the bottom and back of the basin. Feels great!

Overall grade: A+

vertical gap: A+

Note that even the gap between the top of the basin and the spout is significant, meaning that the "vertical gap" between the bottom of the basin and the spout, which largely determines usability, is even roomier.

Rim gap: A+

Plenty of room here too. Your hands never touch the back of the sink.

This sink basin is reasonably deep in all dimensions but the faucet spout could be taller and protrude further into the basin to leave more room for your hands.

Overall grade: B+

vertical gap: B+

Rim gap: B

This combo is so close to achieving greatness. The faucet is plenty tall but unfortunately it curves back down so sharply that the water comes out slightly too close to the back of the sink basin and slightly lower than would be ideal.

Overall grade: B

vertical gap: A

Rim gap: B-

This aesthetically appealing sink has a large basin but it's positioned such that the basin narrows right where you need to wash your hands.

Overall grade: B

vertical gap: A-

The faucet could be slightly taller to leave a larger vertical gap.

Rim gap: B-

The curvature of the basin makes the rim gap too small directly to the right of the faucet spout