The Sears homes were sold via its catalogue, which at the height of its popularity had millions of readers across the USA and Canada. The first catalogue featured 22 styles of home and 447 home designs were created until 1942. Each of the designs could be modified in numerous ways, including reversing floor plans, building with brick instead of wood siding, and many other options. For today’s home builders standardisation is crucial to make certain that they can maintain continuity in demand and in turn achieve obtain the economies of scale necessary to remain financially viable. BoKlok, mentioned above, only has four to five standard designs, which can be customised to suit local requirements. However, unlike Sears, Ikea does not sell its homes in its catalogues - but you can buy one in store! Ikea is also not the only modern day retailer to sell homes. Muji the Japanese brand launched the prefab Muji hut in 2017 and is also testing a prefab house.