Historically, the slums increased in the developed countries with recent modernization and today it becomes the serious problem to be improved. Toward the problem, governments implemented various improvement projects which prepared the legal restrictions on housing and construction to improve the living environment of the slums. But the slums are still existing with illegal construction practices by residents. This paper aims to clarify the reason why people take the illegal way of construction to make their living by analyzing alley space in 70 rai community, Klongtoey, Bangkok, Thailand. The primary data were collected by intensive field work including the drawing of the map of the community, façade and plan of alleys and houses, activity in the alleys, detailed information on residents’ everyday life by interview.
First, the government’s legal restrictions on housing and construction in 70 rai community which was implemented in Site and Service Project at 1985 is described. Building in 70 rai community observed the legal restriction on construction at 1985. In this paper, the houses which were built observing the legal restriction on construction is defined as “Legal extension on provided building model”.
Second, currently living space in 70 rai community will be analyzed to understand general model. This paper analyzes area of site, the number of the floors of each house, and structure. As a result, in 70 rai community, area of site is classified into 4 types and second story with the structure of reinforced concrete and wood are popular. In the area called Ban karun, where the poorest citizens lived, area of site is 2 type and one story with structure of reinforced concrete are popular.
Third, this paper analyzes the ways how to use alley by focusing Soi 12, Soi 13, and Soi 28. Various things are overflowing to outside and people tend to stay under the roof over the alley. It is common that people are talking, resting, eating under the roof and so on. Overflowing things and roofs over the alley work as spatial device and cause people’s specific activity in the alley.
Finally, this paper clarifies illegal construction practices. There are few “Legal extension on provided building model” in Soi 12 and Soi 13 and also in Soi 28. The illegal construction practices can be seen in almost all houses. Moreover, there are 2 types both in Soi 12 and Soi 13. In addition, there are 3 types only in Soi 28. In this paper, illegal construction practices are clarified as overflowing things, the roof over the alley and extending forward, backward and second floor. Following the factors, illegal construction practices are considered based on interview for residents. As a result, illegal construction practices is limited only within the acceptable or allowable level among people. On the contrary residents see whether or not are prevailing among people, “anyone” had already done those illegal practices. It cases the illegal practices.