In 18th-century Paris, buildings were usually narrow (often only six meters wide feet); deep (sometimes forty meters; 130 feet) and tall—as many as five or six stories. The ground floor usually contained a shop, and the shopkeeper lived in the rooms above the shop. The upper floors were occupied by families; the top floor, under the roof, was originally a storage place, but under the pressure of the growing population, was usually turned into a low-cost residence. In the early 19th century, before Haussmann, the height of buildings was strictly limited to 22.41 meters (73 ft 6 in), or four floors above the ground floor. The city also began to see a demographic shift; wealthier families began moving to the western neighborhoods, partly because there was more space, and partly because the prevailing winds carried the smoke from the new factories in Paris toward the east.