In the housing market, a town house is generally considered a popular choice and has sustained steady growth. In 2015, the number of newly-registered town houses in the Bangkok metropolitan region was 18,000 units, reflecting a 27.5% increase from the period of 2011 to 2015. Moreover, it has been discovered that the design of town houses in the Bangkok metropolitan region is diverse. As a result, this study aims to capture correlations and factors determining their architectural design. From survey taking, it has been discovered that most large developers’ town houses in the Bangkok metropolitan region belong to two categories. First, a town house consisting of a frontage of 5.7 metres in width. This type of town house is typically two-storeyed. Second, a town house consisting of a frontage of 5.0 metres in width. This type of town house is typically three-storeyed. In terms of space planning, the first category is mostly divided into 3 bedrooms & 2 bathrooms, followed by 4 bedrooms & 2 bathrooms and 4 bedrooms & 3 bathrooms respectively. On the other hand, the second category is mostly divided into 3 bedrooms & 4 bathrooms, followed by 3 bedrooms & 2-3 bathrooms. It is worth noting that both categories have a garage accommodating two cars. The data from the survey show a number of legal correlations. First, the location of the town houses correlates with the Town Planning Act in that how it governs land development results in high land prices which, in turn, raise the price of the town houses. Second, the size of the town houses (which is categorized into small, medium and large according to the Allocation Act) correlates with the location and the land prices. The expensive land prices force the town houses in the inner core of Bangkok to be small and drive others to geographically spread into the inner suburbs, the outer suburbs and other provinces in the vicinity of Bangkok where the land prices are lower. Third, the area measurement and the space planning correlate with the Building Control Act in that it governs specifications, width, the number of storeys and space design. Findings indicate the following characteristics. First and foremost, the 5.7-metre town houses allow easiest space planning and produce the least unusable areas. Second, the reason why the 5.0-metre town houses with 3 bedrooms and 2 bathrooms cannot be built in a two-storey structure is because of the Building Control Act. In other words, unlike that of the 5.7-metre ones, their space planning restricts them to be three-storeyed. Moreover, some developers design a bedroom space smaller than what has been required by law. Third, although most developers claim that their town houses can accommodate two cars, the 5.0-metre ones expose physical limitations. Ideally, a minimum requirement should be 5.5 metres. However, the construction of the 5.5-metre town houses, according to the Building Control Act, is found to have more unusable areas than that of the 5.7-metre ones. Therefore, most of the developers prefer to build 5.7-metre town houses instead
