Green.docx

MATOGHAR OF BUDDHANILKANTHA

Introduction Mato Ghar of Buddhanilkantha is single storey residential building. It sits in an area of 2000 sq. ft. on the foothills of Shivapuri. Hemanta Bohra is the conceptual designer of this project. Being designed and constructed with passive solar techniques is its most salient feature. Mud is the main component of this building and thus has been named as "Mato Ghar". It houses various techniques of passive solar heating in a building through solar photovoltaic panel and solar water heater. The mechanism of floor heating through solar water heating also can be seen in this building but has not been used yet. The Matoghar premesis embodies modern residential virtues of sustainability, climate responsiveness, simplicity and earthquake resistance.

Figure 1: Mato Ghar of Budhanilkantha

Building form and use The building is rectangular in shape. All of the rooms have been arranged linearly along east west direction. The living room, bed rooms are placed in south and kitchen, toilets, laundry and study room has been placed towards north. The windows are made of double glazed aluminium panel with air cavity. The windows cover nearly 10% of total floor area. The windows provide clear lighting inside the building as well as insulate the outer noise to certain amount. The overhangs have been projected from roof so as to provide shade in summer and allow winter sun inside the room. The wall is made of rammed earth. The walls are 18" thick at the exterior and interior partition of the house. The walls are reinforced at different level to resist the seismic forces. The walls are plastered with mud to give smooth texture externally and internally. The south facing walls have big windows to allow sun inside the building for lighting and heating while north facing walls have small windows to resist cold wind. It has two way slope roof.

Figure 2: wall section of Matoghar

The roof has insulation of 2" thick styro foam. the external layer of roof consists of 24 Guage hulas red, under it lies 2"X2" pinewood purlin, radiated aluminium sheet, 2" thick Styro foam insulation, 12 flatten bamboo and bamboo rafters. There is a gap between external layer and purlin which allows the heated air to rise above (Timila Bajracharya, 2014).

Figure 3:Calculation of U-value

Passive Design Passive design is a philosophy that takes advantage of the climate to regulate the temperature in a home without an owner's having to purchase auxiliary equipment for heating or cooling. Matoghar incorporated passive design philosophy. The design takes into consideration the variations in the sun's path during summer and winter, in addition to the direction of winds. Some of the highlights are,  the use of overhanging roofs that obstruct direct sunlight from hitting the walls from the south side. These roofs, apart from protecting the mud walls of the house from rain, serve important purposes in both summer and winter. Due to the angle at which the sun's rays fall, the overhanging roof has been adjusted accordingly to completely block sunlight during summer.  During winter, sunlight enter the building through the glass panels, which are double glazed. Double-glazed windows help retain heat and keep the house comfortably warm. These windows can significantly reduce energy bills and also create an environment that is healthier to live in, compared to when a living area is constantly exposed to artificially conditioned air.  Moreover, the floor plan of most frequently used rooms face south—to get the maximum sunlight. All the other rooms—the bathroom, the laundry room, the pantry—are to the north.

Figure 4: showing interior space

Rainwater harvesting Matoghar also makes use of a water-harvesting system.The groundwater situation in Budhanilkantha,is good so that its not difficult to dig very deep to hit a spring. The roof of the house (which also serve as insulators) features catchment areas that collect rainwater. It is deposited into a 30,000-litre tank. "We flush away the first few litres of rainwater so that all the dirt and impurities on the roof do not enter the tank," says Bohra. "We depend a lot for our household needs on the rainwater collected. And when this tank is full, we use the excess rainwater to recharge groundwater." (Shahi, 24 Jun 2017) Apart from this, the house also makes use of waste-water recycling. All the water from the showers and the sinks are considered gray water, and are stored separately so that they can be used to water

the plants or wash car. The water from the bathrooms are all directed to a septic tank, where it is treated and subsequently reused.

Aesthetics Another benefit of using rammed-earth is the way it looks. The design may not appeal to everyone, but rammed-earth houses have a certain earthy contemporary aesthetic. For example, the walls have a layered look, resulting from the tamping down of the earth during construction. The effect is similar to the layers in sedimentary rocks. The interiors of his house, which are mostly furnished with wicker furniture, complement the earthy feel of the walls, which is left unpainted.

Figure 5: Unpainted interior wall

Constructed wetland There is a constructed pool, said as wetland which sits as a replica of an actual pond. The artificial pond makes use of reed beds to form a mini water-purifier system of sorts within the pond. The pond is lined with gravel, on which the reed beds grow. The dirt in the pond, dust from the air, or dirt as a result of swimming in it is cleaned by the micro-organisms thriving on the roots of the reed bed. These organisms make use of the aforementioned impurities to obtain nutrients, leaving behind clean water fit to swim in.

Solar power Solar panels that generates 2.8 kilowatts of electricity per second are used to generate electricity (Shahi, 24 Jun 2017). All of this energy is stored in inverters, and is then channeled to the appliances. Solar panels are even used to power induction cookers. In his house, a single gas cylinder (which functions almost as backup) lasts for about four to five months. Almost 90 per cent of his total electricity need comes from solar power, and it can be completely set off the grid if it is wished to.

Farming/Gardening There is ample amount of land besides the area occupied by the house and pond. The space is used to grow a food forest of sorts. Most of the usual seasonal fruits and vegetables are grown. Currently, the Bohra household grows potatoes, tomatoes, mangoes, lychees, apples, oranges, pomegranates, grapes, kiwis, passion fruits, pecan nuts, guavas, papaya, amla, lapsi, olives, curry leaves, mint, lemons, bananas, corn, among many others. The fertiliser that is used is organic too. The house has

Figure 6: gardening and constructed pond

domesticated rabbits, whose solid waste and urine is used to fertilise the plants. In addition to all this, companion planting is also done which makes use of various plants for pest control and pollination. For example, tomatoes are planted and has surrounded them with marigold which is one of the most well-known plants for repelling pests.

References Shahi, R. (24 Jun 2017). Eco-conscious living. M&S Vmag. Timila Bajracharya, S. R. ( 2014). Energy Efficient Building in Kathmandu Valley –. kathmandu: Proceedings of IOE Graduate Conference.