Kitchen sinks and faucets have changed dramatically in the last decade. Sinks are deeper with more shapes than ever before; faucets have changed from three-piece units with separate hot-and-cold knobs to sleek single-level units and back again.
What you want to pay attention to is the operation of the faucets - especially if they're going to be mounted in front of a window or a bar top.
Here, let us show you an example with the sink window:
See how little space there is between the sink and the window?
If we had to estimate (because this kitchen is a couple of years old now and we;re going from memory), there's about an inch of clearance between the back of the faucet and the white window sill.
One inch. Not a lot of room.
Part of the issue is that a window sill protrudes over the counter space depending on the material below it. (In this case, slate tile, so we have a 3/8" tile and the overhang 1/2" beyond it.)
Add to that the kitchen sink depth that we talked about in the beginning - sinks have grown in depth from 16" to up to 20" and more. Take away the 1-1/2" for the front edge of the countertop to overhang past the cabinet case and there's not much counter depth left (3") in a 25-1/2" countertop - even when one sink is smaller than the other sink.
Thankfully, the faucet has the lever on the top which tilts upward. So far, so good, right? Right.
But what if the clients didn't want that faucet? What if they wanted a faucet with a side lever, like the one at the left here? Now we have an issue because the lever not only tilts out to the side, it tilts backwards as well. Bang. Straight into window sill.
While we're at it, let's say "ow" for the client's knuckles -- they're not going to fare much better.
If this detail isn't thought out prior to installation, the poor client will either be buying a new replacement faucet OR installing the base of this one at a 45 degree angle -- which might not be all they were hoping for. (This picture shows the base at a 90 degree angle, but it's not something that stirs a lot of enthusiasm here.)
Please note that we're not trying to single out this faucet (a Grohe Ladylux faucet) as being at fault. That's not the case at all -we really like this faucet. It, and many other side-lever operations as well as reproduction 3-piece faucets (the Moen Showcase "bridge" faucet as an example below right) simply require us to pay more attention to how they operate. 
Here's what we'd look for at the design stage:
* Lower the windowsill enough to free up the operation of the lever, and/or,
* Change the depth of the sink cabinet to a minimum of 26"-27" (depending on how custom the cabinets.) (As an added note, it's always helpful if the countertop installers are made aware of this so they won't center the sink in the space but will fabricate the sink cutout as close to the front edge of the cabinet as possible.)
So, the faucet in the top picture wasn't a lucky co-incidence -- it was something discussed with the homeowner to make sure everything was working as it should.
And now you know what to watch for. Your knuckles will thank you. :)
