SUSTAINABLE CITIES - SUGGESTIVE APPROACH FOR EVOLVING ENERGY EFFICIENT DESIGN OF URBAN SETTLEMENTS;

SUSTAINABLE CITIES - SUGGESTIVE APPROACH FOR EVOLVING ENERGY EFFICIENT DESIGN OF URBAN SETTLEMENTS

*Ar Jit Kumar Gupta; [email protected]

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Introduction

Human Settlements are fast emerging as major entities consuming large resources of non-renewable and conventional energy. ?Rapid increase in urban population coupled with in-migration from rural hinterland is making cities grow larger and larger.?Accordingly, metropolises, megalopolises and ecu-monopolies are fast emerging on the urban settlement scenario.?Cities like Bombay (158lacs).?Calcutta (125 lacs) and Delhi (108 lacs) are assuming monstrous proportions and in this process are encompassing larger and larger hinter-land within city limits.?Bigger the city grows, larger becomes the distance between place of work and place of living; place of recreation and place of living; place of living and educational, medical and other facilities essential for day to day living of human beings.?These elongated distances increase travel needs of the city and accordingly more and more people are required to be transported to their work centers, place of living, place of recreation and place of amenities and services.?Thus transportation network comes under lot of pressure to keep the city moving. In the process more and more buses are pressed into service and more and more private vehicles come on the roads for ferrying people to their destinations.?The means of transportation require vital fossil fuel as source of energy to run the vehicles and accordingly city starts consuming larger and larger quantum of petroleum products.?The quantum of energy required by city to keep it going depends upon its size and this consumption level is in direct relation to the size of the city and grows in leaps and bounds beyond certain limits in the increase of the city size

Human Settlements in general and urban areas in particular require lot of energy not only for transporting people but also for construction of houses and other buildings, for making living more comfortable by providing energy for cooling and heating of living space in different seasons besides running industry and services which form the very basis of urban structure. Very little attention has been paid to understand and analyse the energy implications of urban development on large scale. Unfortunately the issue of energy required to keep a city moving has never been addressed and focused by professionals including Town Planners, Architects, Engineers and Administrators involved in planning, designing, development and managing the urban centers.

With globalization, liberalization and opening up of Indian economy, urban centers in general and metropolitan centers in particular are fast emerging centers of investment, generating enormous employment opportunities in the process. Thus not only more and more people are being attracted but more and more vehicles are being inducted in urban centers. With phenomenal increase in the income of urban areas, energy consumption patterns of the cities have been greatly distorted. With limited resources of non-renewable fossil fuel available, the increased consumption has led to considerable energy crisis, hitting the national economy to a great extent. Greater demand of fossil fuel by fast developing economies including India and China has also led to considerable increase in the price of the oil fuelling inflationary forces in the process. Thus the issue needs to be viewed both in the context of national economy and energy implications. Looking objectively and critically, there appears to be ample opportunities for achieving economy in energy by evolving appropriate patterns of urban development as significant as those achievable through the design of buildings.

Energy Consumption Patterns

Before looking at the options available for evolving energy efficient human settlements, I think it will be essential to understand the consumption pattern of energy in the cities by the end uses.?Study in this regard has been made in U.S.A. and it has been observed that 25% of energy is used in transport (which is almost entirely accounted for by petroleum products), 19% by the residence, commercial use consumes 15% (for servicing the buildings) and rest 41% by the Industry.?Of the energy used in buildings which is of the order of 35%, energy used for heating space accounts for 18% followed by water heating and air-conditioning.?In U.K. the consumption patterns are similar with the difference that energy consumed by transport is bit lower because of compact, small size of the U.K. and lower car-man ratio.?However, higher proportion of energy budget goes for space heating. In U.K., Transport and buildings together consume around 60% of the energy and the area offers opportunities where savings can be affected in the consumption patterns to make cities more energy oriented.

In one of the Seminar on Global Climate Changes, the consumption pattern of energy in 1986-87 and 2004-05 in India were stated to be as under: -

Sr.No.?Sector? ??????????????????????Energy Consumption??????????????????????????????????????????????????????(86-87) %age?????????????????(2004-05)?%age

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1.????????Industry??????????????????????57.7????????????????????????????51.1

2.????????Transport???????????????????19.4????????????????????????????22.7

3.????????Household??????????????????12.7????????????????????????????19.8

4.????????Agriculture?????????????????8.7?????????????????????????????4.8

5.????????Services??????????????????????1.5?????????????????????????????1.6

From the above table it can be seen that transport and household together account for 1/3 of energy consumed in 1986-87 which has gone up to 42.5% showing an increase of 30% during 1986-2004 period.?Though the transport energy figures include not only intra-city but also inter-city traffic but still it shows that transport sector is the second major sector consumer of the fossil fuel.?Industry consumes more than half of the energy. Looking at the overall scenario there appears to be?considerable scope of affecting economy if our transportation requirements are rationalized, specially in the context of the intra-city transport needs besides making industry more responsive to the energy consumption pattern.

?Shaping Cities

As already stated that cities are essentially large consumers of energy, accordingly it would be more important if energy as an issue is built in as an integral part of the planning process in order to ensure that all plans put in place for guiding the future growth and development of the cities are based on considerations which minimize the energy consumption. However, it has been observed that while evolving perspective/development/master plans, planners normally do not study the energy implication of the shape and size they adopt for the planning of cities. In fact if one looks objectively at various geometric shapes, one can clearly foresee that certain shapes involve longer road network, longer travel and consequently higher needs of mechanized modes of travel leading to higher consumption of energy. Whereas on the contrary, there are other shapes which makes the city more compact and reduce distances between various parts of the city, making them more energy efficient.

?Grid iron pattern which is usually fancied by the planners have been found to be highly energy inefficient due to invariably longer distance involved in reaching from one part of the city to another part. Chandigarh is a classical example of city planning, which is planned on a purely grid pattern involving sectors, where there is no possibility of reducing distances between any given points. Further, grid iron pattern is not at all suited for putting in place an efficient mass transportation system because of the existence of numerous channels of communication running parallel to one another which encourages the use of individual vehicles. That is why Chandigarh today has the highest car-man ratio.?Thus grid iron pattern needs to be avoided in evolving city plans considering its energy implications. In case if such a pattern is to be adopted then grid iron pattern should be superimposed with diagonal roads or any other mechanism in order to cut travel distance from one end to another end. In the grid iron pattern, option should be to invariably have a mixed land use planning rather than pure land use zoning in order to ensure that each unit is self-sufficient and self-contained in terms of day to day requirements of working , living and leisure of the residents, minimizing travel needs in the process.

?Circular shapes with radial roads offer much better option for evolving energy efficient design of settlement because of the inherent property of a circle having maximum area with minimum of circumference resulting in smaller distance and having the option of rapid inter-connectivity between various parts of the city. Circular shapes are also known for evolving highly energy efficient mass transportation system. Linear cities can be another option for evolving energy efficient human settlements with all activities spread on both sides of the central spine with distances limited to a scale which permits use of non-motorized vehicles.

?Size of the city has also considerable impact on the energy consumption. It has been observed that cities with 3-5 lakh population are most compact and ideal in terms of travel and sustainability. Very small towns do not offer the advantage of the urban centers for economic operations whereas larger urban centers bring considerable complication in city operations. Thus metropolitisation of urban centers needs to be avoided in order to achieve the objectives of energy efficient human settlements. In this regard the role of small and medium towns would be crucial which are more humane and have lower energy requirements because of shorter travel distances.?Accordingly, development of small and medium towns would require focused attention and development input in our strategy of urban development for reducing the energy consumption levels in the cities. The objective of shaping cities should be to evolve a system of city planning which aims at creating cities having high degree of sustainability in terms of energy. The theme of development should be small is beautiful and large is wasteful.

Land Use Planning

If master plan provides the basic frame work of the city, its operational mechanism is largely governed by land use planning and zoning regulations. Land use planning has thus considerable energy implication for the city and its residents in its operational mechanism and accordingly needs to be critically worked out within the energy oriented developmental frame work of the city. Accordingly, there is an urgent need to rationalise our approach to the pattern of land use planning which has made the cities highly energy inefficient.?In the city planning process generally all the human needs of living, working, care of body and spirits are put into water-tight compartments. Different areas in the city are accordingly zoned for Industries, Housing, Working, Education, Commerce and Institutions with the result large scale movement is necessitated for having access to different areas.?Even shopping at the local level within a sector is generally placed??in the center necessitating the use of vehicles for even making daily purchase.?This system of pure zoning for determining land uses needs to be reviewed and where ever feasible concept of ‘mixed land uses’ needs to be preferred as an option of city development.?Cities need to be segmented into smaller units which must be made self-sufficient to reduce travel needs and to cut down the energy consumption levels.?Decentralisation and Mixed land uses should be the watchwords in the planning of human settlements if level of energy consumption is to be lowered and patterns of energy consumption are to be rationalized.?

?Transportation & Pedestrianisation

The invention of the wheel and the automobile has changed the total complexion of human settlements.?Ever since onset of the Industrial revolution in the 18th Century, the human settlements have witnessed enormous growth because of the PULL factor of the cities in the shape of better employment opportunities, better economic opportunities, access to better services, amenities infrastructures and recreation coupled with PUSH factor of rural areas in the shape of less employment opportunities lack of services, amenities etc.?All these migrants made their make-shift residences near the Industries/work centers causing congestion and decay of the central areas resulting in the movement of rich people to the suburbs.?This resulted in the growth and expansion of the cities.?More and more migrants also added to the fringe area development once land within the city got scarce and expensive.?This resulted in increasing distances within the city. The transportation requirements accordingly increased. In fact stage has now reached where the total economy, efficiency and functioning of a city is largely governed by the efficiency of its transportation system.?If Bombay is holding on, it is because its mass transportation system in the city is very effective and efficient.?However, Calcutta and Delhi are not very fortunate.?The major problem in transportation is the conflict between public and private vehicles.?The private transport i.e. Car/Scooter/Jeep etc. are very inefficient though very convenient.?They are highly inefficient so far as energy consumption is concerned.?They have a very poor load factor and highly inefficient engine, which ultimately converts only 10 -15% of the total energy into the Kinetic motion and rest 85-90%, goes waste.?Thus private vehicles consume large amount of energy and accordingly, ?focused efforts are required ?to rationalize the public transport system and make it more effective & efficient if energy consumption pattern of the cities are to be much changed.?We have to ensure transfer of people from private to public transport system so as to minimise use of private vehicles.?Such a system would reduce traffic on the roads, make movement easier, consumption of fossil fuel lower, making cities cleaner in the process due to reduced pollution.?Efforts needs to be made to use solar battery/CNG operated buses on shorter and congested routes to further improve the quality of life and to reduce the energy consumption.

Mechanisms of Decentralisation and Mixed land uses can be used effectively to reduce the distances between different human functions in order to make cities easily traversable.?People should be encouraged to walk down to the place of work, recreation etc. if proper walkways are created.?Over a distance of 3-5 Kms people should be encouraged to use cycles if proper cycles-ways are created.?In the planning of Chandigarh, a network of Cycle-tracks was created for catering to the majority of cyclists of the city and one such Cycle-way was to run through the Leisure Valley, but due to non-realisation of the same the city has started reeling under the pressure of mobikes and two wheelers mechanically powered vehicles creating lot of traffic as well as environmental problems. Example of China can be followed in large cities by creating exclusive Express Cycle ways for the cyclists where only cyclists are allowed to operate with considerable speed even at peak hours of the day.?These express ways have helped in diverting large number of people from motorized to non-motorized means of transport making the congested areas very clean and city highly energy efficient in the process. Thus in the city planning, order of priority in preference for movement should be Pedestrians, Cyclists and public transport. Individual mechanised vehicles should be discouraged in the larger interest of community, city and nation.No energy efficient city should be without a bicycle plan. The bicycle is the most economical and most energy efficient form of human?transportation ever invented. Cycling as a mode of transportation has played an important role even in societies with high income levels. Cycling accounts for 20% of passenger?trips in Basel, 25% in Tokyo; 50% in Groingen, Netherland and upto 77%?in such Chinese cities as?Tianjik and Shenyang.

In order to minimize the distances within the cities, concept of ‘Low Rise High Density’ settlements also need to be given a thought.?Bigger plots, haphazard and ribbon developments in and around the cities are making Indian cities highly energy in-efficient because of greater length of roads, services and trip lengths.?For limiting size of city and making it more energy efficient, it would be important to have a re-look at the existing density patterns, population distribution, size of plots, quantum of open spaces including their placing, norms for covered area, FAR and zoning regulations in order to ensure that available land within the city is put to optimum use and cities are compact enough to have considerable lower energy implications. In fact energy as an issue has to be built in all the mechanisms controlling, regulating and impacting city, its growth development, management and its operation on day to day basis.??

Buildings

The growth of building industry in India is placed at 9.2% as against global average of 5.2%. The annual investment in the building industry which is currently at the level of Rs. 50 billion, is to grow to Rs. 160 billion by 2012. Despite?huge investment, very little focus is being given to the adverse impact on the environment caused by rapid and uncontrolled growth of building industry. The impact is likely to much more pronounced in the case of India because of high growth rate and lack of?control over the use of materials and technology. Looking at the high degree of energy consumption, which is?presently placed at 300 Kwh for ever square meter on annual basis, there appears to be enough options to bring it to realistic level of 100 Kwh with known concepts of energy efficient technologies, adopting?integrated approach to creating built environment, retro- fitting of existing buildings and designing green buildings.

Considering the fact that Building globally use over 40% of world’s total energy, consume 30% of raw materials, 25% of timber harvested, 16% of fresh water withdrawal and?are responsible for 35% of the world’s CO2 emission, 40% of municipal solid waste, 50% of ozone depleting CFC besides making 30% of residents having sick building syndrome. criticality of buildings and their role in minimizing energy consumption and promoting sustainability of human habitat assumes importance, Looking at the high degree of energy consumption, built environment offers enormous opportunities and options in scaling down the energy consumption. Buildings as they are designed, constructed and used have enormous energy implications. With number of people and institutions rushing towards urban centers, energy requirements of cities due to buildings is going to rise sharply in future. Thus built environment is another sector which would require close scrutiny and monitoring for effecting overall economy in the levels of energy consumption. Experience has shown that buildings can be designed to meet the occupant’s needs for thermal comfort at reduced level of energy consumption by adopting an integrated approach to building design. The integrated approach could include shape and size of the building, built form, surface to volume ratio, building efficiency, ratio between length and depth of the building, using simple techniques of building structure, efficient structural design, principles of solar passive techniques in building design, using energy efficient equipment, control and operation strategies for lighting, heating, ventilation etc. using solar energy for meeting the energy needs of buildings, reduced use of transportation energy, replacing energy intensive materials with low energy components etc.

Architects can ensure high degree of energy efficiency both in construction and operation by critically studying the macro and micro climate of the site, applying bio-climatic architectural principles to minimize the impact of adverse conditions and making optimum use of desirable conditions. Effective use of landscaping as an integral part of building design can help in lowering the level of energy consumption in the building.

Orientation is the single most important factor which needs to be effectively used in all buildings designs in order to evolve energy efficient building design by making use of solar radiation and the wind. However, requirements of building design would vary from region to region, state to state and within regions and states. Accordingly, buildings with regard to sun and wind will have to be oriented differently in different regions. In order to ensure that buildings make best use of solar and wind energy, it would be essential that majority of buildings would have the site advantage where such buildings are to be constructed. Accordingly, in this context town planners have important role cast for themselves for ensuring that while preparing the layout plan of the area, due consideration to orientation is given so that maximum number of plots have the advantage of having best orientation. Once this is ensured at the planning level, it would be much easier for the Architects to evolve a design which would be energy efficient. Further, the planners should ensure that ratio of plot width and depth is fixed in such a manner that the entire depth of?built up area allowed on a plot should have access to natural light during the day, minimizing the requirement of artificial lighting. This would be particularly important in case of row housing where plots have the option to draw light from front and the rear only.

Choice of building materials to be used for construction have important bearing on the energy consumption level of the building and can be effectively used in making buildings energy efficient. Using low energy materials, efficient structural design and reduction of energy used for transportation of building materials can help in achieving high degree of energy efficiency in buildings. Choice of locally available materials and innovative construction techniques has clearly demonstrated their usefulness in reduction of energy consumed by the buildings during construction and operations.

Effective use of thermal insulation, treating roof for regulating solar radiation, using cavity walls, locating, sizing and detailing properly windows and shading devices help in evolving design solution which are bio-climatic and ultimately help in reducing energy requirement of the building. External finishes of buildings needs a careful choice in over to regulate the heat absorption by the walls etc.?However, advanced techniques of passive heating and ventilation like trombe wall, water wall and roof based air heating system, wind towers, courtyard, earth-air tunnels, evaporating, cooling etc. can be effectively used for evolving low energy buildings

In the context of evolving energy efficient buildings, role of building industry would be critical in ensuring that only materials which have low energy implications in their production are made available. Government on its part should encourage the industry which produces energy efficient materials and discourages industries which are in the area of energy intensive materials. Industry on its part must also be educated in the context of constant evaluation and monitoring every material in terms of energy. Industry should be encouraged to promote R & D in the area of building materials coupled with support from?BMPTC in order to ensure that energy requirement of each material is thoroughly studied before the material is allowed to be marketed. Specification of all building materials should also include the energy component in order to make Architects/ builders understand the energy implication of material being used.???

Institute of Architects can join hand with Schools of Planning and Architecture, Builders Associations etc. to create awareness about the energy implication of materials in construction and operation. These institutions can evolve clear manuals for the professionals which must be followed by them while evolving layout plans, design of buildings and their construction. In fact it must be made mandatory that each Architect should also clearly specify like structural safety, the building is energy efficient, I.T. companies can effectively contribute by evolving appropriate software for assessing the energy implications of each building at the time of evolving design which architects can effectively use in modulating/ amending their design in order to bring it within the specified norms of energy requirement of buildings. Specialized training programs needs to be worked out by professional bodies in addition to running short term courses for creating awareness and capacity building for ensuring that buildings have required input of making them energy efficient.

High Rise Buildings

With rapid increase in increase in population, massive urbanization coupled with limited availability of land, Architects, Engineers & Town Planners have to evolve strategies and find optimum solutions for housing large population/activities in minimum area with appropriate quality of life. The ever expanding cities have to be contained & travel within cities needs to be reduced if cities have to be made more humane, productive & efficient. Cities have evolved and existed throughout the history because they remain part of civilisation.???????????????????????????????????????????????????????????

Despite distinct advantages, cities have perpetuated worst kinds of living conditions. Traffic and transportation have emerged as the worst gifts provided by cities & towns. Majority of population suffers from depravity and in basic and essential services. Shelter & travel have emerged as the major threat to urban functioning. In the face of given scenario, how we can make our cities/ towns more livable and efficient. Option perhaps lies in using the potential of high rise buildings. Despite numerous limitations and disadvantages defined above, high rise buildings offer numerous opportunities to address major urban maladies by redefining cities and towns.

High rise buildings have enormous capacity to create large volume of built space which can house large number of people and activities sparing large ground space for non -urban uses. Cities can be made more compact reducing the need of long travels. Housing large number of people in few buildings can create well knit & close communities. Providing work space & amenities within/near the buildings would help in reducing travel within the cities. Cities can be pedestrianised, made more humane & eco-friendly due to reduced travel. These high rise buildings can be connected by efficient means of mass transportation minimizing use of personalized vehicles. Cities can look more green, open and eco-friendly.?However, this will require a new planning approach and paradigm shift on the part of Town Planners in evolving strategies for planning and designing of cities, review existing planning tools and principles, work with Architects & Engineers to create Cities which are more sustainable.

?Use of Information Technology

Information Technology has revolutionised the entire concept of human working, living and even thinking. It has imparted high degree of operational efficiency to human beings. Larger access to information and knowledge has opened new vistas in human growth and development. Accordingly, rapid strides made in the field of I.T. are going to have far reaching implications for future growth and development of the cities. City patterns would reshape with relationship between place of work and place of living undergoing qualitative changes. Many institutions would become obsolete with space requirements undergoing substantial change. With I.T. taking the lead, most of the functions related to working, shopping, health, recreation etc. could be performed at or near home with need for travel drastically cut down. Most of the offices will become paperless and individual would work at home. Children need not go to school with best of education being accessed through computers. Extensive use of video-conferencing can cut down the need to travel to larger cities for attending conferences, seminars, and workshops etc. New housing complexes will have larger areas where housing, recreation, eating joints, health clubs etc. provided within the complex. Houses will function as offices and schools. I.T. would help in reducing traffic on the roads making cities cleaner, livable and energy efficient in the process.

Information technology holds enormous promise but its use in urban planning, development and management has to be geared up. It is important that I.T. companies/experts should now start focusing on its use in??urban planning by developing appropriate softwares which would help in evolving energy efficient plans. Let urban development be treated as a specialized and priority area by I.T. sector with immense opportunities offered by the technology which then can be used for helping planners in improving planning practices and planning techniques. Effectiveness and efficiency of planning process and practice in promoting energy efficient settlements would be largely contingent upon how planning profession meets the challenges of future urban development by evolving new approaches and new strategies with the support of I.T. and I.T. enabled services. ?????????????????

???Greening City

Trees have enormous capacity in terms of modulating day time temperature, controlling?humidity and reducing heat emissions during night for balancing temperature. Trees have also critical role in management of water resources because of absorption of enormous free water during precipitation and through release of water through evaporation during?dry period. A single tree is said to transpire 450 liters of moistures on daily basis which is equivalent to 5 room sized air conditioners working for 19 hours. A mature Beech tree has 80,000 leaves with each leave acting as a small organic filter. Canopy of a tree makes up a surface area of 10-12 times greater than area of the ground they shade. Trees have enormous capacity to improve the quality of environment. A tree can filter 20 kg. of SO2?a year without causing harm to itself and?produces Oxygen sufficient to cater to the needs of 10 people. A tree lined street has the capacity to filter up to 80% of pollutants, reduce noise level up to 12 db and lowering of temperature up to 3.5%Greening the cities through extensive landscaping and massive plantation can be used effectively for lowering the overall temperature and to bring the climate within the comfort zone leading to considerable reduction in energy expenditure. Shading of building through vegetation, using trees and shrubs as barriers to direct solar radiation can help in reduction in energy demand. Accordingly, mechanism of greening buildings/ cities should be extensively used to make cities highly energy efficient.

Involving communities and NGOs

Involving communities and NGOs in promoting sustainable cities would be critical. People have to be educated and made aware about their role and responsibility in reducing consumption of energy in their day to day life. They have to be educated in order to change their entire pattern of life from being consumers to producers. They have to be moved away from the materialistic pattern of life so that wasteful activities are minimized. Their pattern of life will have to be molded and reshaped in a manner which minimize unnecessary travel. Use of energy intensive gadgets would also require minimization. Unless people understand and appreciate their role and involvement in the process, it will be difficult to achieve the desired objective of promoting sustainability.?

Conclusion

The way cities use land, consume energy, east up resources and impact the quality of life and environment, they are fast emerging as ecological disasters. Uncontrolled and haphazard growth devours land, water and energy from the surrounding landscape. The emerging contemporary patterns of settlements, have created cities which have high level of consumptions of energy due to auto dependence; high energy demand for buildings; water pollution from excessive toxic run off; air pollution and other environmental effects which considerably increase health risks.

For the exorbitant, energy and ecological prices, these patterns do not even buy an appropriate quality of life. Cities of 21st century are totally divorced from aesthetic and ecological experience of nature. People are made to spend number of hours for commuting on daily basis. In the emerging social fabric, neighbours are not friends, communities are not tied to place and millions?too poor to afford basic amenities of life to lead?a dignified life. Invasion of automobiles has made cities highly noisy, energy inefficient, congested and largely frustrating.

In addition to global macro ecological problems caused by high level of energy consumption by cities, current settlement patterns have created host of local ecological problems. World life habitats have become extinct; native species are replaced by consumptive exotics; streams are canalized, piped and buried; wetlands are filled and aquifers depleted. Urban heat islands created drive up energy use for cooling besides trapping pollutants in the city. Downstream areas are flooded and polluted largely by the quick run off from large paved areas. All these problems, collectively and individually, have the ability to adversely impact the local ecology. Accordingly, local ecological systems are rapidly losing their ability to produce clean water, air and food and to maintain rich variety of habitat. In short, they are fast losing their ability to sustain life.Each of these environmental problems has their genesis in the design of cities, settlement patterns and urban spatial fabric. Human habitat needs restructuring on priority so that we live within the limits imposed by our life sustaining eco-systems and follow the basic principles which promote the quality of life.To minimize the energy consumption levels and the ecological disasters caused by todays grey cities, we have to change our perceptions.. We have to learn to think ecologically to create green cities which are both humane and sustainable besides least consumers of energy.