Brandon Fyfe of Thompson’s Plumbing offers guidelines on choosing a countertop basin:
“Above-counter and underslung basins range in depth; so keep this in mind before you decide on a specific style,” he says. “A standard countertop is 900mm from floor level to the top; because an above-counter basin sits atop the vanity rather than inside it, you can use a vanity below standard height. However, some people prefer a higher countertop; at the end of the day, it all comes down to personal preference.
“These basins have no faucet holes, so taps have to be wall-mounted or deck-mounted on the countertop. An advantage of such a basin is that less cutting is required in the countertop. With a basin that is sunk into the countertop, a hole the size of the basin, whether it’s made of wood or marble, must be cut out of the slab; for basins on top of the slab, only a hole for the drain and a small one for the tap is needed. Thanks to their shape, round or oval basins on top of a slab also take up less space than sunken basins, so there is more room for your toiletries and accessories on the countertop.”