Figure 3.16 - Streets & arrangement of chettinadu residence

3.2.3 Construction technique

1) The street and building orientation

Figure 3.16 - Streets & arrangement of chettinadu residence

(Source – Assessment of the climate-responsive architecture of traditional houses by Radhakrishnan S.)

The orientation of streets is along North - South axis in order to orient the house in East West direction as indicated in Figure 3.16, so as to get good cross ventilation. These traditional residences are planned in such a way that they stretch from one street to another. Hence there is lot of air movement as shown in Figure 3.14 into the building, which is in fact required for houses located in the warm humid climatic zone. These traditional houses are detached houses usually approached by a road not more than 7 m wide in North - South orientation as shown in Figure 3.16.

The knowledge of town planning is appreciable in two important aspects, one is on the knowledge of orientation of buildings and streets and the other is the knowledge of the topography. The layout of the entire village is planned in such a way that the rain water is harvested into the public pond of the village.

The traditional houses are planned with a narrow lane between two houses with extended open spaces all round, these open spaces around the building enabling excellent air movement causing good ventilation inside the houses.

The Chettinadu homes, which have grown over the course of two centuries, are true palaces built on a high plinth level. These palatial houses were constructed during 1740 to 1935 A.D. The special features of these houses are the fore court, verandah, reception halls and courtyards. The rooms are planned along a longitudinal axis, and extend with two or more courtyards, and at the rear side they invariably end with a huge kitchen and a dining hall.

The houses are aligned on East-West axis as shown in Figure 3.16, with the entrance of the house either from the East or from West. Eventually, the longer side of the building walls will face North and South, resulting in longer walls that are less exposed to direct solar radiation. As the prevailing wind direction is East–West, almost all the traditional houses are well ventilated, thus enhancing comfort conditions.

2) The Roof

These houses consists of three distinct types of roofs:• Sloped roof (couple roof). • Sloped roof (couple roof) with a flat roof below (false ceiling called as machu) for the purpose of aesthetics, storing and mainly heat reduction. • The flat madras terrace roof (normally laid when there is a floor above). • Lean to roof (found in the forecourt and in the kitchen area as an extension of the sloped roof encircling the last courtyard as a semi open space).

Among these, the Slope roof is found in the roof of the living space as well as the bed rooms (the study area) around the courtyard. The roof height is 10’ (3.2 meters). The roof is made of handmade terracotta roof pan tiles which are laid in three courses, over the wooden battens fixed in the wooden rafters joined between the purlin at the pitch of the roof and the wall plate above the wall in an angle of 30 degrees slope.