1) Presumably a showroom or warehouse.
When a Sheffield button-maker called Thomas Holy died in 1758 a button house formed part of his premises. The fittings included drawers, shelves, a glass case, and a button table. An inventory of his goods listed more than a quarter of a million buttons made of brass, tin, zinc, pewter, horn, glass or pearl, with some lacquered or silvered. Holy had sold his wares throughout Yorkshire and as far afield as London, and his successors traded in Europe and America.