Here’s a mistake I often see: placing a vessel sink on top of a cabinet with a standard countertop height.
Vessel sinks have become a very popular choice of bathroom sinks lately. The bowl-shaped sink sits on top of the countertop. Whereas the more traditional under-mount sink, or drop-in sink, sits embedded in the vanity, leaving the top edge of the sink approximately even with the countertop.
In the past, bathroom vanity countertops were 30” above the floor. Most people these days prefer this height to be 36”. It’s more comfortable and easier on the back. The mistake comes when installing the vessel sink on top of the (new) standard-height vanity cabinet countertop. The vessel sink can vary in depth,and can be up to 6” deep. So if the countertop is 36” above the floor, the rim of the vessel sink ends up 42” above the floor. This is way too high for most everyone not playing professional basketball. If a vessel sink is the choice for you, you need to take into account the height of the sink and the height of the countertop. If the vessel is 6” deep, it would be best to use a 30” tall vanity cabinet and countertop. This will place the top edge of the vessel sink 36” above the floor, or right where you want it to be.