After his return from the First World War, Wilhelm Niemeier extended his firm rapidly. In addition to furniture, special pieces of plywood, block boards and other similar things were also produced. Until the Second World War, branches in Drakenburg, Braunschweig, Weenzen and, of course, Marienau were acquired, so that the WINI-Group temporary grew up to a crew of more than 1600 employees.