Join Two Vanities Together . Looks like we have to buy it custom built, which for that size is not cheap. Double vanity vs two single vanities side by side. Bathrooms The Inspired Room from theinspiredroom.net Select the cell you want to combine first. It is approx 122 with a 53 vanity on the left (butts up to soaker tub) and a 49 vanity on the right (butts up to wall when entering bathroom). An example formula might be =concat (a2, family).