The absolute minimum walking clearance is 30 in (76 cm), and local building codes may require greater than that.
While standard bar chairs and stools are made to fit a 42 in (110 cm) bartop, it’s easy to find chairs and stools that fit 36 in (91 cm) as well. If you want to have the option of standing and eating comfortably, 42 in (110 cm) is definitely the way to go. [7] X Expert Source Josh GoldenbergResidential Remodeling Expert Expert Interview. 25 January 2022.
Always aim for at least 12 in (30 cm), and, if you have the space and strong bracketing to support the overhang, consider going as far as 18 in (46 cm) for maximum comfort. [9] X Research source
Mark a 42 in (110 cm) high line along the wall and mark the locations of the wall studs to anchor the brackets into. Drill pilot holes and screw the brackets into place so that the tops are at the 42 in (110 cm) line. Cut the bartop to size, if needed, and attach it to the brackets from underneath with adhesive, screws, or both. A solid piece of hardwood, at least 1. 5 in (3. 8 cm) thick, is a good choice here.
Remove the old countertop, being careful not to damage the cabinetry. Measure, mark, and install support brackets into the cabinet structure. Alternatively, install “invisible” supports, which are flat metal rails that run under the entire countertop and cantilever out to support the overhang. Install the new countertop, using a combination of adhesive and screws.
