Small affordable Green Buildings

Category: Environment & Green Technology Published: Sunday, 24 April 2016
Salient features of most of the green rated buildings are observed to be good landscape, lawn on the roof, use of solar panels for lighting, SIBF for waste recycling.Though all these features have high potential of enhancing green rating, their use is restricted to large budget building complexes in urban area and cannot be employed in majority of middle income group buildings having low budget and land availability. The purpose green building concept will be served only when it is widely accepted and this requires affordable green alternatives from capital cost and maintenance requirements.
The adoption and acceptability of any new system by common man is generally governed by capital cost and not pay back. This is because he has no spare capital to invest in items which would be beneficial in the long run. He has many other short term and urgent priorities for the money he has with him. Easy loan and financing options can change this trend. There is need of taking proactive role by financial institutions in providing finance for such green technologies.

Provision of lawn on roof, no doubt, is an effective method of utilizing solar energy for cooling roof through evapo-transpiration, but this requires water proofing of roof, soil cover which increases roof weight, watering system requiring water pumping, and reular maintenance of lawn. The cost of such a system is prohibitive resulting in its sporadic use.

 

Use of reflective paints have limited effect on preventing roof heating but is widely accepted as it is affordable. Provision of garden with earthen pots with harvesting of vegetables and flowers may be via media alternative which may be widely accepted.<br />Solar panels for electricity are not economically feasible if used with conventional lighting systems. Use of low wattage CFL and superbright LEDs along with solar panels can give economically viable alternative. The design of building to take full advantage of direct and indirect lighting coupled with provision of CFL / LED lamps at locations considering task lighting requirements can yield very effective and energy efficient lighting system. Intense lighting requirements on kitchen platform and reading table and ambient lighting in rooms can be met by CFL lamps of appropriate wattage, The parking, starecase, common entrance which require continuous light can be provided by solar powered LED lamp modules with light sensor auto switch off system.
Provision of constructed wetlands or SIBF requires large area and hence cannot be used in buildings with limited plot area. If the building is lifted on supports making land below builtup area available for such units is one solution. These units can also be provided on community basis in colonies, where there is some area reserved for common amenities. The construction cost of SIBF can be considerably reduced if geosynthetic membrane is use for pond lining. Local flowering plant species should be used. Mosquito breeding can be prevented by using subsurface flow system in design of these units.

Biogas plants Biogas plants for treating domestic waste and kitchen waste can yield biogas and good fertilizer, however, it is recommended for building complex or colony and not for individual houses because of maintenance requirements. Use of biogas is not yet widely accepted due to presence of H 2 S and smell nuisance it creates while using biogas for cooking. The corrosion of pipes is another problem.Removal of H 2 S and CO2 by passing biogas through alkaline water can solve this problem. The conventional building in India has linth, walls and roof as rigid components which ive strength security and durability to the structure. Critical examination o hse components in the light of present day needs of green and sustainable building indicate rethinking as regards their design principles and funtional requirements. The plinth is provided for raising the floor level above ground surface to protect it from moisture, tree roots and rodents. This is achieved by creating wall enclosure and filling the the inner space by murum or stabilized clay. However, such support dosnot guarantee rigid base for floor tiles and with time the tile surface becomes uneven due to subsidence of filled soil. Intead of filled plinth, the floor slab can be supported on short columns and the underneath ground surface can be kept unobstructed ensuring minimum disturbance to surface ecosystem, free passage to water flows and opening up large area for rain water storage, waste treatment plant, pumps and flexible openings for entry of cool air in the building.<br /><br />Walls give the rigidity to orientation and shape of building. The fixed locations of door and window openings also impose severe restrictions on provision o natural ventilation and lighting. Can we not have walls with flexibility of relocating by sliding or turning mechanisms. Such a provision will dramatically make the house flexible enough to take maximum advantage of sunlight and wind in different seasons.

If walls provide support to roof and roof is heavy the walls require strength and rigidity. The framed structure relieves the walls from this requirement, but the the cost increases due to RCC structure. The question then arises about fixed heavy roof. Why we require heavy roof or for that matter, why at all the roof is required? For providing shade from sun (protecting inner environment from heat and glare of sunlight) and protection from rain. There one more vital reason for sturdy roof ie security. What are disadvantages of fixed roof? It confines the space and obstructs natural light and ventilation. Can we have light, sturdy and openable or roofs using modern materials and mechanisms. Various innovative ideas can be explored to make the walls and roof flexible and responsive to changes in requirements.<br />House on turntable or house on wheels are extreme solutions. Tribals have been using light weight temporary houses constructed with local materials, which can be constructed or dismantled in short time without a dent on natural surrounding.
The present building technology seems to be completely governed by building component manufacturers. They influence the fashion and choice of materials. As a result, the buildings are adorned with costly, showy and mass manufactured synthetic products. Use of natural and locally available materials or alternative low cost materials is looked upon as substandard and undesirable, though more ecofriendly and affordable. Ceramic tiles, glass shading films, modern plumbing fixtures, paints and coatings are some exaples.Unless this trend is changed, it is difficult to have desired large scale impact of green concept.
It is necessary that architects, engineers and designers should ask why to every material they use and examine it in the green perspective. All the alternative materials need to be compared as regards functionality, cost and ecofriendly rating.