When Mr and Mrs Prataprai Bosamiya wanted to get away from the hustle and bustle of the town after retirement, they wanted Brinda and Parth of BPS Architects, Rajkot to design a house that was not just energy efficient but also green. The main concern of the design was to build minimum and use innovative construction techniques which would be helpful to the villagers too.
The house is located on the periphery of a village called Rajsamadhiyala, 18km away from Rajkot city. It sits on a mound and next to the village water tank. Being a hilly region, the site and the plot offered breath taking vistas of the horizon. The location of the main house is towards north and the landscape design is done towards the southern part of the plot. Overall site preparation is divided into two parts – landscaped area towards south where endemic shade giving trees are to be planted and the natural open part towards the north. Ground fixing is only done with locally available bricks to provide direct access to the usable open areas and that too without any impervious sub grade thus allowing maximum rain water to percolate.
The orientation of the functions are best suitable to efficiently use the sun direction, hence reliance on artificial lighting and ventilation is very minimal.
The physical features of the site were the guiding reference for the location of the main house and the annexe. The rock out crop area on site became a court for the house, which was a generative of the design. The extreme and lowest south- west corner, adjoining the village roads became the annexe to house utility, parking and guard’s room.
The language of both the built forms is designed extremely different, separating the response to the village as well as their functionality. The main house is divided in two parts – the bedroom and the kitchen, by the court. Both these spaces offer very different vistas.
The location of the kitchen was decided keeping in mind the views it offered; of the village temple and village houses. The views were accentuated by placing a window directly above the kitchen platform. The semi-covered living space and the bedroom enjoy the solace and expanding views.
The annexe was built to meet the needs for the utility of the main house. Its location was chosen keeping in mind the level difference of the site, and the views for the main house.
This house demonstrates its simplicity not only by its location or function but also by the restraining form and use of local materials.
A building when designed sensitively becomes energy efficient not only in terms of materials sourced but also in terms of how they are put together in terms of construction methods. Such buildings have less material wastages and require less maintenance. This house demonstrates its simplicity not only by its location or function but also by the restraining form and use of local materials.
The construction techniques and the material palette were governed out of budgetary constraints and more importantly to introduce alternative construction methods in a village.
The walls are made out of locally available bricks and Kalmidh (black Basalt stone). Several old windows and doors were procured from broken building yard to be conserved and reused. The masonry openings of the window in the main house and in annexe were carefully derived in design for reuse purpose and to suit the function. In the spaces where large openings for view were important, aluminium section were used. The opening sizes are designed and located as per the old windows procured from windows of demolished buildings.
The roof was designed as a vault made with the hollow circular fired earthen pots (terracotta tumblers) in main spaces. The circulation areas have flat roof with filler slab made with fired earthen circular bowls. The vault is an adaptation of technique developed by Centre of Science for Villages (CSV), Wardha for low-cost housing and modified here for more affluent clients. This construction method achieves faster erection time (only three days from start to removal of shuttering; another week for the mortar to set); uses no steel or concrete (as in a conventional RCC slab). Since it is a catenary curve and is in pure compression, it requires minimal support for load bearing. The roof thus saves time and labour resource. However, it is still economical compared to RCC and is more resource conserving.
The flat roof (in RCC), wherever required, is designed in cognisance with the idea to save on the concrete being used in the slab. The fired clay bowls are used as filler material to reduce material consumption. The bowls in turn are locally produced cutting down on total volume cost by 30%. The parts of the paving through the landscaped part are done by locally available used and recycled fire bricks from kiln and waste ceramic jar lids. The fire bricks from the kiln were used as second flooring material along with the Kota stone. These bricks were also used on top of the kitchen platform finished by a transparent waterproofing, replacing costly granite stone.
Primary building materials such as brick, stone and terracotta tumblers (for the roof) were resourced locally reducing the cost of procurement. It also helped enhance the local skills. For example, during the course of the project, one potter was given the special task of firing the tumbler in order to derive the desired colour.
The planning and span of the main spaces was governed by the vault dimension. The vault shape was derived from prefabricated metal truss frame used earlier in similar vault construction.
The use of the old wood windows and aluminium windows added a flavour to the house for its location in the village as well as speaking of contemporary vernacular.
The paving was done with glazed ceramic jar lids, and fire bricks from kilns procured free from the ceramic factory sites as waste material. This had multiple advantages; using industrial waste, not using fresh materials, clearing the debris sites near to the ceramic industries, opening of the top soil etc.
The walls of semi open areas of the living room are kept rough keeping in mind the semi-arid nature of the site. It adds a rustic feel typical of a village house. These areas have rough stone flooring along with fire clay brick patterns. The interior of the bedroom and of the kitchen are similarly plastered keeping in mind the need to achieve a certain level of cleanliness. These areas have polished natural stone finish.
The use of old windows, ceramic waste material and the vaulted roof was introduced in a village to make villagers aware of alternative construction techniques and materials, and also to increase awareness towards saving on resources.
Rain water collected on the roof is fed into a 5000 litre underground tank. This will be sufficient to provide drinking water to the family during the water scarce summer months from March to June. Waste water from the kitchen is directly fed in to the vegetable garden and provision for a grease trap is made to remove access oil component.
There is a provision for a bio-gas plant (not installed currently). When the desired occupancy levels are reached (two adults and two children using the toilets everyday) and in the next phase, this gas plant can generate gas enough to cook food one time a day for a family of four. Thus the overall savings would be 50% of the conventional LPG usage.