In late 19th and early 20th century saw the development of residential areas in Tallinn in the neighbourhood of the factories. These areas were built up with two-three storey wooden apartment buildings, a type of house gradually evolving which came to be known as a 'Tallinn house'. This was built of cheap and readily available local material - timber - and was divided into two in the middle by the stone staircase stipulated by the fire safety regulations. In the suburbs, this type of house was the most widespread; it was rather a local peculiarity, rather than the work of a particular architect.