National Centre for Sustainable Coastal Management
Competition entry for this Centre tries to imagine the relationship between people of the coast and the sea
To the people living next to the ocean, the coast-line is not a line. The ocean pervades sensibilities of people deep inland: the air laden with the smell and taste of the sea, the cool breeze despite the blazing sun, and a feeling of being gently guided by the forces of nature though life’s everyday rituals. Our attempt at the design for the National Centre for Sustainable Coastal Management, first, tries to imagine this relationship between people and the sea. The coast, not the imaginary line that separates land from sea, but a stretch that brings the two together; where one loses itself in the other. The relationship of the building to the outdoor space mirrors this relationship. Buildings weave into the landscape creating not a single large building or green space but structure and garden interlaced.
Our attempt at the design for the National Centre for Sustainable Coastal Management, first, tries to imagine this relationship between people and the sea. The coast, not the imaginary line that separates land from sea, but a stretch that brings the two together; where one loses itself in the other. The relationship of the building to the outdoor space mirrors this relationship. Buildings weave into the landscape creating not a single large building or green space but structure and garden interlaced. In the past, people on the coastal belt built with what the land provided: timber, bamboo, thatch, clay and mud, in a way that required neither processing energy nor energy to cool the interiors. Rapid urbanisation of coastal districts has ravaged this relationship between man and environment. Our second endeavour is to build in a way that respects that relationship between the building and its environment: the siting of the building, orientation to the sun and breeze and materials used that belong to the soil where the building plants itself. Our third motivation is to also bring to the fore a personal and subjective involvement with the notion of ‘building by the sea’ that is nourished by our own experiences of the ocean and archetypes of the maritime. We were moved by the geological formations of the Sunderban deltas where the land gently surrenders itself to the sea, images of boats on the beach, and of great sea-faring vessels with sails billowing in the wind. We have carried these images while designing and have allowed them to emerge and guide our sketches. We believe that this gesture is important for our habitats to make the journey from engineering to architecture.
Site Planning & Functional Organisation
The buildings are sited such that most of the trees on site are preserved. This has been a major concern for the building setting out. Peripheral Roads give accessibility and fire tender access to all blocks while keeping the internal outdoor areas vehicle free. The buildings are further oriented keeping the sun and wind in mind. The land has been allowed to maintain its natural contours and minimal cut and fill has been considered. The north west part of the building drops in height to provide views towards the river from upper levels. We believe that the NCSCM despite having its own institutional identity belongs to a larger domain of the academic environment of the Anna University and to global efforts at creating sustainable human habitats. In such a role, its own building ought to open its doors to cross disciplinary interactions across campus and other departments of the Government doing similar work. The functional layout of various departments within the building follows such a notion where institutional individuality makes way for porosity and transparency. The building is organised into three interconnected blocks whose widths ensure optimum day-lighting and cross ventilation. A fourth minor block towards the south east houses the cafeteria and food courts. The south most block houses large span laboratories and research areas while the central block comprises of mainly administrative and conferencing areas. The north most block has offices and workspaces for the GIS Datacentre, Digital Photo Grammetry, National Data Centre etc.
Vehicular movement is expected to be generated from the stretch of road marked in the site plan as the main approach road for the building. However the possibility of approaching the building from the east side has not been ruled out. The vehicles follow two roads on the North and south edges of the site with cul-de-sac terminations. The possibility of a full loop around the site is possible for emergency vehicles. Pedestrian accessibility in the centre is vehicle free and shall be designed on the principles of universal accessibility. Clear movement corridors tie the blocks of the institution together and vertical movement cores have been conveniently placed at the terminations of such inter-connections.
ORIENTATION AND PASSIVE SOLAR DESIGN
The proposal for the NCSCM building follows primarily a passive solar approach to design where orientation and shading become the most important moves towards long term savings in energy costs. Using elements such as Operable windows, thermal mass and thermal chimneys in vertical stacks and stairwells, the building ought to maintain a comfortable temperature even without cooling. The interspaces between buildings are imagined as corridors oriented SE-NW towards the prevailing wind direction. The wind that is directed through green spaces and dense vegetation provides an amenable micro-climate which is then sucked in thermal chimneys.
PASSIVE COOLING THROUGH EARTH AIR TUNNELS
We propose a method of cooling with earth air tunnels that are buried 3m below the surface of the earth. The optimum length required to cool air drawn in through these tunnels and pumped inside the buildings is provided by the long access road. The approx. 2m x 2.5m wide tunnel shall be constructed before the road metalling and lined with anti-fungal coating. This shall provide a temperature as low as 28-30 degrees Celsius even during the hottest summer days where the outside temperature is 40 degrees. Our experience with having such tunnels designed and executed in 3 other such projects provides us with faith in its efficacy. Even if air-conditioning is required hereafter, the load on the compressor will be minimal. The economics of earth air tunnels show a pay-back period of about 5 years in hot tropical climate zones.
SOLAR POWER GENERATION
Captive Solar PV based power generation using the roof surfaces of the buildings is envisaged for the buildings. Apart from providing 8 points for the LEEDS platinum certification, the power generation can be a suitable replacement for diesel based power generation. We expect to generate 40% of the total lighting load of the building to come from Solar based power. Battery stores shall be placed in the basement.
MATERIALS AND CONSTRUCTION
We believe in using low-energy materials that are local to area. The use of local materials and technologies which utilise them could become exemplary for many coastal environments in India providing livelihood to many. NCSCM must lead the way in the right choice of material and technology.
COMPRESSED STABILISED EARTH BLOCKS & FERROCEMENT VAULTS
We feel that using Compressed Stabilised Earth Blocks (CSEB) along with precast ferro-cement vaults for the floors and roof provides one such way of building that utilises less cement and steel, is labour intensive (thus providing employment opportunities to many). At the same time utilisation of such precast technologies allow for parallel site activities and therefore save time and are quick to erect.
A cubic meter of CSEB is cheaper than regular bricks and requires 15 times less energy and causes 8 times less pollution to produce than the same volume of fired bricks.
The combination of CSEB and ferro-cement vaults apart from having low embodied energies, these have excellent thermal properties. There is also the possibility of employing local labour and generating employment for many. Research done at the Auroville Earth Institute has been adopted for CSEB blocks and Hourdi blocks (CSEB blocks designed for use with ferrocement vaults and beamsin floors and ceilings). These are produced locally by semi-skilled people. Therefore, the need for importing materials from far away spending on transportation and production costs has been found to be unnecessary.
USE OF BAMBOO
The choice of industrialized products for building by the ‘developed’ world not only has negative ecological ramifications but also suppresses activities in rural areas and small towns. Renewable materials are wasted while products having massive embodied energy are produced at the expense of non-renewable sources. In this sense, it becomes imperative that , making use of agricultural by-products such as rice husk, coconut fibres, sisal and bamboo and therefore minimizing energy consumption, conserving non-renewable natural resources, reducing pollution and maintaining a healthy environment. Bamboo is one material, which will have a tremendous economic advantage, as it reaches its full growth in just a few months and reaches its maximum mechanical resistance in just few years. Moreover, it exists in abundance in tropical and subtropical regions of the globe. The energy necessary to produce 1m3 per unit stress projected in practice for materials commonly used in civil construction, such as steel or concrete, has been compared with that of bamboo. It was found that for steel it is necessary to spend 50 times more energy than for bamboo. The tensile strength of bamboo is relatively high and can reach 370MPa. This makes bamboo an attractive alternative to steel in tensile loading applications. This is due to the fact that the ratio of tensile strength to specific weight of bamboo is six times greater than that of steel. (Ghavami, 2004)
We shall consider the use of bamboo as reinforcement material in the concrete columns and beams. Bamboo shading screens form an integral part of the building vocabulary cutting glare, preventing direct solar radiation to heat up building walls.
If the NCSCM adopts bamboo as a building technology, it can give a boost to Tamil Nadu’s bamboo production which now trails several other states despite having large areas under bamboo plantations.
SOIL BIO TECHNOLOGY SEWAGE TREATMENT
Whereas, the STP has already been marked on an area towards the river downwind and away from the building, we would like to provide inputs on the nature of the Sewage treatment plant towards a more sustainable form of treating sewage with active soil media which breaks down organic matter much quicker than in water as in conventional STPs.
Soil Biotechnology (SBT) is an environment friendly waste processing technology that offers systems for processing of both solid organic wastes and wastewater treatment using bacteria, earthworms and mineral additives in a garden-like setup. This technology was initially developed at Indian Institute of Technology (IIT), Mumbai over two decades of research. Since it reinforces the carbon and nitrogen cycles in nature, the quality of the treated water meets State pollution control board standards reducing Chemical Oxygen Demand (COD) nitrates to very low levels unlike any other STP method.