Chapter – 7
(Biswajit Bose, Senior Architect & Biswajit Roy, M.Arch. (Landscape), Architect, CPWD)
• To provide shade to the parked vehicles.
• To divide the parking bays physically, generally after 9 cars To absorb air pollution
• To reduce noise pollution
• To add softness and aesthetic quality to otherwise paved areas To reduce the heat generated from the paved surfaces.
Parking can be arranged in small units informally set amongst existing mature trees, preferably with loosely defined parking bays paved with gravel or grass-concrete.
Hedges and shrubs can be used to break up long lines of vehicles, and to provide windbreaks against dust and rubbish blowing across the area.
Parking bays can be grouped on different levels, separated by embankments planted with low cover.
The trees should be planted between raised curbs or in elevated boxes to avoid hazards like vehicles backing into them and tree roots poisoned if fuel run-off gets into the water supply.
Plantation Criteria and Plant Characteristics The trees should be litter free. The trees should not be fruit bearing as fallen fruit can damage the surface of vehicles. The trees should be evergreen in nature so as to provide protection from sun rays causing discoloration of the painted surface of the vehicles.
The plantation scheme should be efficient wherein required amount of shade can be achieved through minimum number of trees.
The trees in parking areas should not be shallow-rooted or else the roots might come out on the paved surfaces.
The trees should be fast-growing.
The trees should cater to broad scale environmental aspects like being effective pollution sinks to absorb lead from vehicles etc.
The trees should have dense foliage with large surface area and preferably fine-leaved trees to absorb pollutants.
Cattle should not be able to feed on these trees.
Suggested Plant Material
• Ceiba pentandra
• Chorisia speciosa
• Cassia fistula
• Chukrassia tabularis
• Gmelina arborea
Turf Pave: A New Age Solution for Landscaped Parking
At the time of emerging demand for more and more car parking space in or around project premises and increased quantum of hard concrete and road to facilitate such parking, plastic Turf Pave has brought in some sense of sigh and relief.
Turf Pave is a light weight robust plastic grid structure, specially designed to stabilise and support turf, grass or decorative gravels used for landscape. It provides an environment friendly and practical alternative to impermeable surfaces like concrete and asphalt.
Positioned under a grass landscape, Turf Pave distributes load from pedestrian and vehicular traffic to the base course below, minimizing grass and root compaction. The interconnected plastic cells allow roots to develop with minimal restriction, resulting in a durable and stable grass surface.
• Stabilize turf/ grass surfaces and protects soil against erosion.
• Pleasant alternative to asphalt and concrete surfaces.
• Enhances site appearance through green vegetation.
• Reduces need for storm water conveyances and treatment systems.
• Minimizes storm water run- off.
• Slope stabilization and erosion control.
• High water permeability.
• Distributes vehicle weight. Depending up on the manufacture, high compressive strength can withstand load up to 200T/Sq.m.
• Rapid installation with minimal trained manpower and tools.
• Off site preassembling of modules.
• Vehicle parking lots.
• Sports complexes.
• Street shoulder parking on unstable ground.
• River banks and canals for soil stabilization on slopes.
• Rot and insect resistant.
• Ozone resistant.
• Solar UV resistant.
• Corrosion resistant.
• Recycling potential.
• Warranty up to 20 years (varies from product to product)
• Light weight.
• Manufactured from 100% recycled plastics.
Excavate and/ or level the area.
Install drainage systems and utility lines in the sub grade, as required.
Lay and compact sand gravel to provide support for estimated weight bearing load.
Position turf pave cell modules on compacted sand and gravel base.
Cover turf pave with recommended sand soil mix for turf establishment.
Apply recommended moisture, water retention agents and fertilizers.
Place rolled turf or hydro- seed onto the filled turf pave modules.
Many international and local manufacturers are now producing Turf Pave. The users need to check the quality beforehand for the best results. The CPWD first used Turf Pave in the Jawaharlal Nehru Bhawan Project in New Delhi. After seeing its performance the product is now being used in the other CPWD projects.
Chapter – 8
Climate and Vegetation
(Text Source : mnre.gov.in)
The climate of any place depends on many natural and manmade factors like: Location, Altitude, Latitude, settings with respect to land profile, location of water bodies, lakes, rivers or ocean in the surroundings, rate of rainfall or precipitation, sun shine, wind direction, and speed of winds, type, size, location and intensity of vegetation and buildings or structures.
The air temperatures in densely built urban areas are often higher than the temperatures of the surrounding countryside. The term “urban heat island” refers to increased surface temperatures in some pockets of a city, caused by an ever changing microclimate. The difference between the maximum city temperature (measured at the city centre) and the surrounding countryside is the urban heat-island intensity.
An urban heat island study was carried out in Pune, Mumbai, Kolkata, Delhi, Vishakapatnam, Vijayawada, Bhopal and Chennai by MNRE Govt. of India. It is seen that, among the cities listed above, the heat island intensity is greatest in Pune (about 10°C) and lowest in Vishakhapatnam (about 0.6°C).
In the metropolitan cities of Mumbai, New Delhi, Chennai and Kolkata, the corresponding values are 9.5, 6.0, 4.0 and 4.0°C respectively. The density of the built environment and the extent of tree cover or vegetation primarily affect the heat-island intensity. Pollution and heat due to vehicular traffic, industrialisation and human activities are other contributing factors.
Normally, the central business district (CBD) or the centre of a city experiences higher temperature than the other parts. This is because the CBD mainly consists of concrete buildings and asphalted roads, which heat up very quickly due to radiation from the sun. Most of this heat is stored and released very slowly sometimes even up to the night.
The phenomenon does not allow the daily minimum temperature to become too low. Though it may be a welcome phenomenon in cold regions during winters, it makes life unbearable for people in the hot regions. Thus, in tropical climates, the provision of sufficient ventilation and spacing between buildings is required to allow the cumulated heat to escape to the atmosphere easily. Street patterns and urban blocks can be oriented and sized to incorporate concerns of light, sun, and shade according to the dictates of the climate.
For example, the densely built areas produce, store and retain more heat than low-density areas. Thus, the temperature differential between urban areas and the surrounding countryside increases as the surrounding areas cool at night. As a result, cooler air from the surrounding countryside flows towards the centre. This kind of circulation is more pronounced on calm summer nights and can be utilised to flush dense areas of heat and pollutants.
Toachieve cool air movement, a belt of undeveloped and preferably vegetated land at the perimeter of the city, can be provided to serve as a cool air source. Radial street patterns can also be designed for facilitating movement of air from less dense to more dense areas.
A system of linear greenways or boulevards converging towards the city centre will help to maintain the movement of cool air. Provided the soil is adequately moist, a single isolated tree may transpire up to400 litres of water per day. This transpiration together with the shading of solar radiation creates a cooler environment around the tree.
On a hot summer day, the temperature can drop significantly under trees due to cool breezes produced by convective currents and by shading from direct sunlight. Planted areas can be as much as 5-8°C cooler than built-up areas due to a combination of evapo-transpiration, reflection, shading, and storage of cold. Local wind patterns are created when the warm air over a dense built up area rises, and is replaced by cooler air from vegetated areas. Having many evenly distributed small open spaces will produce a greater cooling effect than a few large parks.
Studies suggest that for a city with a population of about one million, 10-20% of the city area should be covered by vegetation for effectively lowering local temperatures. As the vegetation cover in the city increases from 20 to 50%, the minimum air temperature decreases by 3-4°C and the maximum temperature decreases by about 5°C
The heat released from combustion of fuels and from human activities, adds to the ambient temperature of the city. Air pollution, caused mainly by emissions from vehicles and industries, reduces the long wave radiation back to the sky thereby making the nights are warmer. Global solar radiation during daytime is also reduced due to increased scattering and absorption by polluted air (this can be up to 10-20% in industrial cities).
Pollution also affects visibility, rainfall and cloud cover. Effective land use to decongest cities, and the provision of proper vegetation would mitigate the effects of pollution. It is also important to use cleaner fuels and more efficient vehicles.
Meteorological studies and remote sensing by satellites can be used to ascertain drastic changes in the climate, land use and tree cover patterns. Remote sensing can also be used to map hot and cool areas across a city by using GIS tools (Geographical Information System). Such mapping can help to reduce unplanned growth of a city, in preparing a proper land use plan, and to identify future vulnerable areas (those devoid of natural vegetation, parks and water bodies). These measures would certainly help in reducing urban heat island intensity.
The conditions for transfer of energy through the building fabric and for determining the thermal response of people are local and site-specific. These conditions are generally grouped under the term of ‘microclimate’, which includes wind, radiation, temperature, and humidity experienced around a building. A building by its very presence will change the microclimate by causing a bluff obstruction to the wind flow, and by casting shadows on the ground and on other buildings. A designer has to predict this variation and appropriately account for its effect in the design. The microclimate of a site is affected by the following factors:
• Water bodies
• Street width and orientation
• Open spaces and built-form
An understanding of these factors greatly helps in the preparation of the site layout plan. For example, in a hot and dry climate, the building needs to be located close to a water body. The water body helps in increasing the humidity and lowering the temperature by evaporative cooling.
Landform represents the topography of a site. It may be flat, undulating or sloping. Major landforms affecting a site are mountains, valleys and plains. Depending on the macroclimate and season, some locations within a particular landform experience a better microclimate than others.
In valleys, the hot air (being lighter) rises while cooler air having higher density, settles into the depressions, resulting in a lower temperature at the bottom. Upward currents form on sunny slopes in the morning. By night, the airflow reverses because cold ground surfaces cool the surrounding air, making it heavier and causing it to flow down the valley. Moreover, the wind flow is higher along the direction of the valley than across it due to unrestricted movement.
On mountain slopes, the air speed increases as it moves up the windward side, reaching a maximum at the rest and a minimum on the leeward side. The difference in air speed is caused due to the low pressure area developed on the leeward side.
Temperature also varies with elevation. The cooling rate is about 0.8°C for every 100m of elevation. Air moving down the slope will thus be cooler than the air it replaces lower down, and vice versa. Further, the orientation of the slope also plays a part in determining the amount of solar radiation incident on the site.
For example a south-facing slope will get more exposure than a north-facing one in the northern hemisphere. Studies conducted in Mardin, Turkey showed that building groups located on a south facing slope in the city needed approximately 50% less heat to maintain the same indoor temperature as buildings located on the plain land. Careful positioning of a building with respect to landform can thus help in achieving comfort.
Vegetation plays an important role in changing the climate of a city; it is also effective in controlling the microclimate. Plants, shrubs and trees cool the environment when they absorb radiation for photosynthesis. They are useful in shading a particular part of the structure and ground for reducing the heat gain and reflected radiation. By releasing moisture, they help raise the humidity level. Vegetation also creates different air flow patterns by causing minor pressure differences, and thus can be used to direct or divert the prevailing wind advantage.
Based on the requirement of a climate, an appropriate type of tree can be selected. Planting deciduous trees such as mulberry to shade east and west walls would prove beneficial in hot and dry zones.
In summer, they provide shade from intense morning and evening sun, reduce glare, as well as cut off hot breezes. On the other hand, deciduous trees shed their leaves in winter and allow solar radiation to heat the building. The cooling effect of vegetation in hot and dry climates comes predominantly from evaporation, while in hot humid climates the shading effect is more significant.
Trees can be used as windbreaks to protect both buildings and outer areas such as lawns and patios from both hot and cold winds. The velocity reduction behind the windbreak depends on their height, density, cross- sectional shape, width, and length, the first two being the most important factors.
When the wind does not blow perpendicular to the windbreak, the sheltered area is decreased. The rate of infiltration in buildings is proportional to the wind pressure. Therefore, it is more important to design windbreaks for maximum wind speed reduction in extreme climates, than to attempt to maximize the distance over which the windbreak is effective.
In cold climates, windbreaks can reduce the heat loss in buildings by reducing wind flow over the buildings, thereby reducing convection and infiltration losses. A single-row of high density trees in the form of a windbreak can reduce infiltration in a residence by about 60% when planted about four tree
heights from the building. This corresponds to about 15% reduction in energy costs. Thus, trees can be effectively used to control the microclimate. The data for various trees found in India are presented in the Table :
Water bodies can be in the form of sea, lake, river, pond or mountains. Since water has a relatively high latent heat of vaporisation, it absorbs a large amount of heat from the surrounding air for evaporation.
The cooled air can then be introduced in the building. Evaporation of water also raises the humidity level. This is particularly useful in hot and dry climates. Since water has a high specific heat, it provides an ideal medium for storage of heat that can be used for heating purposes.
Large water bodies tend to reduce the difference between day and night temperatures because they act as heat sinks. Thus, sites near oceans and large lakes have less temperature
variation between day and night, as well as between summer and winter as compared to inland sites. Also, the maximum temperature in summer is lower near water than on inland sites.
The wind flow pattern at a site is influenced by the presence of a large water body in the following way. Wind flow is generated due to the difference in the heat storing capacity of water and land, and the consequent temperature differentials. During the day, the land heats up faster than the water, causing the air over the land to rise and be replaced by cool air from water. Hence the breeze blows towards the land from water during the day and in the reverse direction at night.
Evaporative cooling can help to maintain comfort in buildings in hot and dry climate. This feature was successfully adopted in vernacular architecture. For example, the Deegh palace in Bharatpur is surrounded by a water garden to cool the neighborhood. Other examples include the Taj Mahal at Agra and the palace at Mandu. The evaporation rate of water in such an open space depends on the surface area of the water, the relative humidity of the air, and the water temperature.
Street Width and Orientation
The amount of direct radiation received by a building and the street in an urban area is determined by the street width and its orientation.
The buildings on one side of the street tend to cast a shadow on the street on the opposite building, by blocking the sun’s radiation. Thus the width of the street can be relatively narrow or wide depending upon
whether the solar radiation is desirable or not. For instance in Jaisalmer (hot and dry climate), most of the streets are narrow with buildings shading each other to reduce the solar radiation, and consequently the street temperature and heat gain of buildings. It is seen that street temperatures in Jaisalmer can be up to 2.5°C lower than the ambient air temperatures due to mutual shading of buildings. At high latitudes in the northern hemisphere, the solar radiation is predominantly from the south; hence wider east-west streets give better winter solar access.
The orientation of the street is also useful for controlling airflow. Air movement in streets can be either an asset or a liability, depending on season and climate. The streets can be oriented parallel to prevailing wind direction for free airflow in warm climates.
Smaller streets or pedestrian walkways may have number of turns (zigzags) to modulate wind speed. Wind is desirable in streets of hot climates to cool people and remove excess heat from the streets. It can also help in cross ventilation of buildings.
This is important in humid climates, and at night in arid climates. In cold regions, wind increases heat losses of buildings due to infiltration. For restricting or avoiding wind in cold regions, the streets may be oriented at an angle or normal to the prevailing wind direction. For regular organisations of buildings in an urban area, tall buildings on narrow streets yield the most wind protection, while shorter buildings on wider streets promote more air movement. When major streets are parallel to winds, the primary factors affecting the wind velocity are the width of streets and the frontal area (height and width) of windward building faces.
Open Spaces and Built-form
The form of a building and the open spaces in its neighbourhood affect the radiation falling on the building’s surface and the airflow in and around it. Open spaces such as courtyards can be designed such that solar radiation incident on them during daytime can be reflected on to building façades for augmenting solar heat.
This is desirable in cold climates, and it is possible if the surface finish of the courtyard is reflective in nature. Inside a courtyard, wind conditions are primarily dependent on the proportion between building height and courtyard width in the section along the wind flow line.
The courtyards can also be designed to act as heat sinks. Grass and other vegetation in a courtyard can provide cooling due to evaporation and shading. Water sprayed on the courtyards would cause cooling effect due to evaporation. Consequently, the air temperature in the courtyard can be much lower compared to street or outdoor air temperatures in a hot and dry climate.
The air in open spaces shaded by surrounding buildings would be cooler and can be used to facilitate proper ventilation and promote heat loss through building envelope. Built forms can be so oriented that buildings cause mutual shading and thus reduce heat gain. For ensuring unobstructed airflow, taller structures can be planned towards the rear side of a building complex.
Chapter – 9
Green Building Environment & Landscape
(Indu G. Choudhary, M. Arch. (Urban Design) Senior Architect)
We need to acknowledge the basic reality that the building industry on one hand uses 40% of total energy, 42% of water and 50% of raw materials; and on the other hand it is responsible for 50% air pollution, 42% green house gases, 50% water pollution, 48% solid waste and 50% CFC (chlorofluorocarbons). There is no denying the fact that human habitat is an essential part of a civil society but at the cost of nature. The natural resources are limited and depleting very fast. Thus we must enforce measures of sustainability and live in harmony with nature. The fundamentals of the sustainable design approach are reducing the requirement, consumption and wastage of the resources; selecting ecologically sustainable materials, reusing and recycling them. We may also utilize renewable energy sources and generate energy on site.
The awareness, knowledge and implementation of sustainable planning and design techniques among professionals & users are needs of the hour. Conscious efforts need to be made in this direction by all concerned while designing buildings and open spaces for the users in urban as well as rural areas. The Green building design approach has gained momentum among professionals through sincere efforts made by the various government and non-government agencies in India and innumerous initiatives and steps taken by them in this direction in the last decade.
The depleting greencover in the cities shall be arrested through conscious application of environmental and landscape process and techniques while undertaking various development projects. Thus the landscaped approach shall be carried in a holistic manner by adding the green cover and preserving the existing vegetation to maintain a balance between natural and built environment. The landscape design has to be responsive to the local climatic conditions for its survival and sustainability.
It is important for the professionals to collect and analyse the site with respect to orientation, climatic conditions, soil, water & hydrology, wind direction, existing vegetation and slopes etc. The design intervention involves preserving and protecting landscape during construction, soil conservation, including existing site features, reducing hardscape/ hard paving on site, reducing landscape water requirement, optimizing building design to reduce conventional energy demand, waste water treatment, water recycling and reusing (including rainwater), storage and disposal of waste, resource recovery from waste and reducing outdoor noise levels and innovative use of new materials.
CPWD has recognized the above and takes pride in following the green building design approach and if implementation in all its projects. CPWD has also published a guide on “integrated green design for urban and rural buildings in hot-dry climatic zone”. The exhaustive information on sustainable development, green building environment and rating systems etc. is available on web sites of the various government and non government agencies.
Chapter - 10
Landscape Design - Imperial Delhi
(S.S. Rawat, Architect, CPWD)
Imperial Delhi is known for its tree lined avenues. Captain George Swinton, Chairman of the Town Planning Committee, referring to the creation of Imperial Delhi reported in 1913:
Trees will be everywhere, in every garden however small it may be, and along the sides of every roadway, and Imperial Delhi will be in the main a sea of foliage. It may be called a city, but it is going to be quite different from any city that the world has known.
The brief to the Architects was to retain one-third area as green space. The garden city concept was chosen as the planners felt a crowded city was not the answer to any metropolis.
Extending from the Central Vista is the hexagonal road pattern, which spreads north and south of Rajpath distributing traffic on shady avenues lined with regular plantation of indigenous trees. An important feature of the planning was the presence of major public green open areas on three sides of the Lutyen Bungalow Zone (LBZ). These are the Delhi Ridge on the west adjoining the Presidents Estate; the connected green of Nehru Park, the Race Course and the Delhi Gymkhana Club, Safdarjang Airport, Safdarjang Tomb, and the almost contiguous Lodi Garden on the south; the Delhi Golf Club on the south-east, and on the eastern side across the LBZ boundary along Mathura Road is the large green expanse of the Zoological Garden, with the Purana Qila at one end and Humayun Tomb at the other. This resource of green areas is the most valuable asset, not only of the LBZ but of the entire city of Delhi, because of the fresh air and natural beauty that the green areas represented. New Delhi is probably the only city in the world where the centre of the city is 4 degrees Celsius cooler than the peripheral areas. The bungalows are spread over just 1.8% of entire Delhi’s area but these very green spaces contribute immensely to the ecology of the city.
Planning for the Avenues. The various flowering and evergreen trees were used along different roads. Only one type of tree was used in one road.
List of Major Avenue Trees in NDMC Area
(Source: NDMC Website)
||Janpath, Park Street, Mother Teresa (Mixed), BKS Marg
||Aurangzeb, Shahjahan, Prithviraj, Aurbindo, Tees January, Safdarjung, Kamal Attaturk, KG, Rafi, Talkatora Road, Lodi, Sansad Marg, Pandara Road, Jai Singh, Jantar Mantar, GRG.
||Tilak Marg, Akbar Road, Teen Murti Marg
||Ashoka, Rajpath, Sunehri Bagh, Tughlaq, Motilal Nehru, Feroze Shah, Raisina, Rajaji, Tyagraj, Kushak, Talkatora Road, Tolstoy, Mahadeva Road
||Purana Quila Road, Babur
||Krishna Menon Marg, Dr. Zakir Husain, Bhagwan Das Road, Blawant Rai Mehta Lane, Nyaya, Niti Marg, Dalhousie, Bhagwan Das Road, Satya Marg, Church Road.
||Mother Teresa Road, Panchsheel Marg, Sardar Patel, Mandir Marg, KG, Africa Avenue
||Dr. Rajendra Prasad Road, Barakhamba Road.
||Maulana Azad Road, Mansingh Road(Part)
||Niti Marg, Nyaya Marg
||Rajesh Pilot Marg (South end Road)
||Pterygota (Buddha’s Coconut)
||Bishambhar Das Marg
||Gmelina arborea (Gamari)
||B - Avenue, Sarojini Nagar
||Alstonia scholaris (Saptaparni)
||Vinay Marg, Kautilya Marg, Kitchner Road, Safdar Hashmi, Tansen, RK Ashram Marg
||Malcha Marg Market
||Chandragupta Marg, Amrita Shergill, Humayun Road
||Ficus benghalensis (Bargad)
||Teen Murti Road( Part)
||Large Mixed Gulmohar, Lagerstroemia thorelli, Polyalthea longifolia
||South Avenue, North avenue,
Chapter – 11
Landscape Design Concept-1
Paryavaran Bhawan, Aliganj, Jorbagh, New Delhi
(P.S.Sodhi, M. Arch. (Landscape), Architect, CPWD)
Landscape Design Concept
Ministry of Environment & Forest is the nodal agency for planning, promotion, co-ordination & overseeing the implementation of country’s overall environmental and forest policies and programs.
Indian subcontinent is one of the most fascinating ecological and geographical regions in the world. It offers enormous diversity in topography, natural resources and climate as well. In landscape design proposal for Paryavaran Bhawan, we tried to represent the overall geographic regions of country; where each one has its own natural, ecological value of India.
These regions will be represented in the form of plant material, rocks, artifacts and pictorial representation in & around proposed building. The proposed plant material selection is based on MoEF’s guidelines for different agro-climatic zones, judicious mix of biodiversity value and aesthetics. The tree components in Paryavaran Bhawan complex will represent the indigenous flora of the country depending on adaptability to Delhi’s climate.
Role of Biodiversity in the Design Development
Design for Biodiversity promotes the ecological function of a built structure and environs in its local context. This requires not only the consideration of how a built structure can minimise any adverse impact upon the local ecology, but also a consideration of whether the built structure or its landscaped environment can deliver any wider ecological benefits or enhancements. Considering this approach designing for biodiversity has been undertaken in a sympathetic manner in this project so that it can fulfill not only the requirement of Green Building but also offer a number of other benefits to user and public visiting the ministry. The main considerations undertaken for landscape design are:
Demonstrating social and environmental responsibility;
To recognise the importance of environmental agenda by integrating environmentally sensitive approaches into project development;
To meet LEED & GRIHA requirements for getting Platinum and Five Star rating for proposed building;
Financial savings compared with a traditional landscaping approach; • To provide users and occupiers of buildings a diverse landscape;
To educate visitors about the environmental benefits provided by reduced storm-water run-off, shading, insulation or ‘natural air-conditioning’ etc.
The task for demonstrating the entire biodiversityof the India in such a small area is difficult but the aim is to show the commitment of ministry towards environment and forests. One of the main aim objectives of this project is to get highest rating of LEED and GRIHA to make this building a role model for Green Building.
Green Building is the practice of creating structures and using processes that are environmentally responsible and resource-efficient throughout a building’s life-cycle: from siting to design, construction, operation, maintenance, renovation, and deconstruction. This practice expands and complements the classical building design concerns of economy, utility,durability, and comfort.
Although new technologies are constantly being developed to complement current practices in creating greener structures, the common objective is that green buildings are designed to reduce the overall impact of the built environment on human health and the natural environment by:
• Efficiently using energy, water, and other resources
• Protecting occupant health and improving employee productivity
• Reducing waste, pollution and environmental degradation
Green building brings together a vast array of practices and techniques to reduce and ultimately eliminate the impacts of buildings on the environment and human health. It often emphasizes taking advantage of renewable resources, e.g., using sunlight through passive solar, active solar, and photovoltaic techniques and using plants and trees through green roofs, rain gardens, and for reduction of rainwater run-off. Many other techniques, such as using packed gravel or permeable concrete instead of conventional concrete or asphalt to enhance replenishment of ground water, are used as well.
Benefits of Green Building are:
• Enhance and protect biodiversity and ecosystems
• Improve air and water quality
• Reduce waste streams
• Conserve and restore natural resources
• Reduce operating costs
• Create, expand, and shape markets for green product and services
• Improve occupant productivity
• Optimize life-cycle economic performance
• Enhance occupant comfort and health
• Heighten aesthetic qualities
• Minimize strain on local infrastructure
• Improve overall quality of life
Landscape Design Approach
The thematic sections in the central courtyard area would include special plant groups such as Palms, Cycads and other tropical elements of high conservation value (e.g. Medicinal Ginger). Water bodies to be introduced as central feature in the court yard to soothe micro climate and to introduce sound effects.
Special attention will be given to the illumination of laid green areas with energy efficient lighting arrangements to create dramatic effects particularly in central courtyard and terrace garden
A sandwich space in-between gym & entertainment area at seventh floor will be designed to provide relief and to refresh. This is a vegetated surface on a roof, playing a part in slowing down rainwater runoff, helping to keep the building cool, ameliorating the ‘urban heat island’ effect, and contributing to the filtration of pollutants from the atmosphere.
Green Wall is used to describe a vegetated vertical surface particularly on the solid walls. This will provide an opportunity for wildlife in locations where conventional landscaping is impractical; providing visual amenity for the public. In addition to these; green walls can also help with rainfall attenuation, dust filtration, and reducing the urban heat island effect.
The proposed plants material suggested for this project has been taken after considering the diversity of plants. The suggested trees shrubs and ground covers are adaptable to the climatic conditions of the area. Since in Delhi the ground water level is low, hence the maximum care has been taken to plants the trees and shrubs which require minimum quantity of water and can survive in dry climatic conditions. Most of the trees & shrubs to be planted in the area have very good growth and are varied according to the climatic, soil conditions and the planting distance.
Most of the plants are Indian origin and can withstand to the adverse climatic conditions. Different trees have to be planted in the four different directions of the Paryavaran Bhawan i.e. North, East, South and West. Maximum care has been taken to select the tree species according to their suitable directions. On the terrace garden as well as in the internal courtyard species of Champa have been taken to give a beautiful look with its broad green leaves, white & creamy flowers.
Few selected plants such as Chinar, Rudrakash & Glacier Ivy suggested to give representation to the mountain areas are new to the Delhi climatic conditions and need special attention for their growth. Best efforts will be taken to make their survival in its new ecological condition.
Large spaces particularly below the trees grove are planted with ground covers to provide aesthetics, to hide the barren soil which otherwise can’t be planted with grass or other shrubs control erosion of soil and to slow down the surface runoff effectively
As suggested by GRIHA & LEED, number of trees to be cut down will be replaced by new trees planted in the ratio of 1:3 + 25% extra to gain one point
Deciduous trees are planted on the Southern and Western side to maximize the benefits of deciduous trees; this will help shade the lower parts of the building during the hottest months of the summer and when these trees drop their leaves, they allow sunlight to warm building during the winter.
Water collected from rainwater harvesting will be used for irrigation purposes to reduce municipal storm water runoff. To minimize the wastage of water drip irrigation systems (micro-irrigation systems) will be placed to deliver water directly to plants.
Composting occurs in nature and is a process that keeps organic nutrients cycling from soil to plants and back to the soil. Composting has many benefits, including: (1) Reducing municipal waste, (2) Improving soil moisture retention, (3) Boosting plants’ immune systems, and (4) Reducing the need for chemical fertilizers. Organic waste from fruit peels, grass clipping, leaves, etc. is to be recycled and mixed into garden soil.
Chapter – 12
Landscape Design Concept - 2
Hostels for Central University of Rajasthan at District Ajmer.
(Sudhir Kamal Seem, M. Arch. (Landscape), Senior Architect, CPWD)
The proposal is for construction of Scholars’ Hostels of about 800 Students to be constructed on a piece of land measuring 218.33 hectares at Bandra Sindri, Ajmer district of Rajasthan. The land is situated on NH-8 about 90 kilometers from Jaipur.
The land is irregular in shape and is surrounded with agricultural fields without any type of buildings in around 2 km radius, and very little vegetation cover as the land was being used as grazing fields for the villages.
The site is gently sloping in two directions with highest point in the centre and the gradient ranging between 1% - 2%. Highest point is 101.50 m, lowest point is 83.50 m.
The top soil is loose earth with exposed rocks at many areas and excavated ditches at some pockets. Thereby no top soil at places to 5-6 m soil cover at some places.
Excavated ditches in some parts on south west are found with over burden of excavated earth on some parts of the site. To be dealt with carefully with eco sensitive approach.
No prominent vegetation worth preservation. Vegetation at site is mainly of scrub (thorny bushes} xerophytic in nature. Green pockets are seen near recharge earthen bunds constructed at site
It is proposed to construct 4 hostel blocks of 200 students each. The design has been evolved such that the buildings can be used as offices and class room/laboratories etc. For a short period of time and will be converted to hostels as and when required without much changes and extra expenditure.
Since the master plan of the university was not finalized it was proposed to use the approach of minimal intervention. The buildings were planned on one corner of the site using very small piece of land in order to have maximum flexibility for planning / design of master plan for entire site.
• Gently sloping site- Gradient 1% - 2 % Highest point 101.5 m, Lowest point 83.5 m Generally loose earth with exposed rocks.
• Excavated ditches in some parts on south west due to mining. Mining area to be dealt with carefully with eco-sensitive approach.
Wind flow and Vegetation
• Wind direction in the region is mainly north westerly winds.
• No prominent vegetation exist worth preservation
• Vegetation on site is mainly thorny bushes xerophytic in nature.
• Green pockets are found only near recharge structures.
• A later study has shown that the site is part of a potential wind energy corridor therefore, half of the left part of the site has been reserved for wind mills.
The storm water flow is mainly sheet flow in S-E and S-W from highest point. Three recharge earth bunds have been preserved and an additional bund has been created at the lowest point to contain Rain water runoff from site and recharge the aquifer.
A tentative master plan was prepared before the design of above buildings to justify the proposal.
The proposal for providing comfort cooling (without refrigeration) in the Hostel buildings. Different options are given for the cooling for each of the Hostel buildings. Each Hostel building will have different air cooling system.
Design Goals for the Comfort Cooling System
• Low capital cost.
• Low operating cost.
• No use of Refrigerant.
• Maximum comfort by maintaining inside conditions below 30ºC
• Better Indoor Air Quality.
• Minimum Water Consumption.
• Use of geothermal energy.
• Minimize Environmental damage.
• Minimize Use of Energy.
Basis of Design
||44°C DB ; 23.9°C WB
||35.0°C DB ; 28.3°C WB
||07.2°C DB ; 05.0°C WB
||To maintain the temperature in between 26°C- 30°C
15-20 Air changes/Hr and 10 ACPH for displacement ventilation
||2 person/ Room
||Designed on 100% fresh air.
||1.5 watts / sqft
||1 watts / sqft
Option 1 : Hostel Building - 1
Earth Air Tunnel System with Evaporative Cooling The heat will be rejected in two steps in this system.
The first stage of heat rejection will be inside the earth air tunnels.
The ambient air at 44 deg C will be brought down to 32-33 deg C.
With the Earth Air Tunnel the air will be pre-cooled without adding any moisture to it. There will be a special designed evaporative cooling unit after the Earth Air Tunnel.
The air coming from Earth Air Tunnel will be passed through the evaporative cooling unit which will bring down the temperature to 20-21 °C from 32 °C.
The cool air from the unit will then be passed into the rooms through insulated masonry vertical and horizontal ducts. The distribution inside the rooms will be done through a special perforated Grilles at the floor level of each room. The exhaust air will be taken out through the grilles below the roof level of the Room.As the system is not based on mechanical exhaust the baffles needs to be placed after the exhaust grilles so that the exhaust air cannot be effected due to High atmospheric pressure outside the room.The temperature of 27-29 deg. centigrade will be maintained inside the room.The system is based on 100% fresh air supply to the hostel rooms.
Option2 : Hostel Building 2
Geothermal Boreholes with evaporative Cooling The system is based on 100% fresh air.
The heat from the ambient air will be rejected in two steps in this system.
The first stage of heat rejection will be done through the water in the pipes which is Inside the boreholes.
There will be a closed water loop inside the borehole.
The water from the geothermal boreholes will be pumped in the special designed AHU Coils where the heat rejection will take place.
The ambient air at 44 deg C will be cooled down to approx 35 deg C without adding Moisture it.
Evaporative cooling will be done in the second step inside the AHU.
The cool air from the unit will then be passed into the rooms through insulated G.I. vertical and horizontal ducts.
The distribution inside the rooms will be done through the grilles below the ceiling Level of each room.
The exhaust will be taken out from a lower level inside the room.
As the system is not based on mechanical exhaust the baffles needs to be placed after the exhaust grilles so that the exhaust air cannot be effected due to high atmospheric pressure outside the room.
The supply ducts will run on the ceiling level of the corridors on each floor.
The temperature of 27-29 degree centigrade will be maintained inside the room.
Option 3 : Hostel Building - 3
Two stage Evaporative cooling.
The first stage of two stage air washers will pre-cool the ambient air without adding any moisture to the air. The second stage of the two stage air cooling system will be the direct evaporative cooling. The first stage cooling is the alternative solution for the earth air tunnel system.The proposed two stage air cooling system is recommended because the region has hot and dry climate. The cool air will be taken through insulated G.I ducts to the rooms where the air will be exhausted out from the grilles. The temperature of 26-29 degree centigrade will be maintained at a certain air velocity inside the room which is quite comfortable.As the system is not based on mechanical exhaust the baffles needs to be placed. After the exhaust grills so that the exhaust air cannot be effected due to high atmospheric pressure outside the room.
Option 4 : Hostel Building – 4
Air cooling by wind towers with misting nozzles
This system will be based on 100% fresh air supply to the occupants. The concept of the system for the hostel building is that we will have a wind catcher which will bring the air from the fourth floor level to the ground floor level and in between the air will be cooled through the mist. There will be misting nozzles inside the wind tower through which the dry and warm ambient air will be passed. The temperature of the air will be brought down to 24–25 deg C with the addition of moisture in it from misting nozzles. This cool air will be supplied to the rooms with the help of the blowers in the AHU Room on ground floor through insulated G.I. ducts. The wind catcher will be made of masonry and it will be insulated.
As the university was running in the rented premises about 25 Km from the site and was not able to get additional accommodation for running new courses it was decided to finish the buildings without installing the cooling systems as mentioned above. Only the features to be inbuilt in the structures were completed such as:
i. The Walls of the habitable spaces (HOSTEL ROOMS) were insulated with XPS Panels,
ii. The roof of the building was insulated with XPX foam,
iii. Stone frames for Doors were installed,
iv. UPVC window frames with double glass panes were installed.
v. Vertical shafts for earth Air Tunnel,
vi. Basement with Earth Air tunnel Shaft constructed under the corridor.
vii. Orientation of building is such that the habitable spaces are insulated by placing non-habitable spaces on east and west sides in order to reduce radiation.
viii. The shape of building is designed as/ best orientation.
It is found that a temperature difference of 5 ºC has been recorded in the insulated areas and non insulated areas.
A temperature difference of 10-15 ºC has been recorded between inside and outside temperature.