Introduction to Green Buildings & Built Environment

Introduction

In India, the building sector is booming and is contributing to its economic growth immensely. This augurs well for the country. It’s also the right time green concepts and techniques that can aid growth sustainably are introduced. These can help address national issues of water and energy efficiencies like reducing fossil fuel used for commuting, handling consumer waste, and conserving natural resources. Most significantly, the concepts can enhance occupant health, productivity, and well-being.

Confederation of Indian Industry (CII) established the Indian Green Building Council (IGBC) in 2001. IGBC’s vision is to enable a sustainable built environment by 2025. With the support of stakeholders in the construction sector, IGBC is leading the green building movement in the country and is striving for a wider adoption of green concepts in buildings and built environment.

The Indian green building movement stands tall globally today, with over 6,781 green building projects registered with IGBC, with a footprint of over 7.86 billion sq. ft. IGBC has a set a target of 10 billion sq. ft green buildings by 2022.

BENEFITS OF GREEN BUILDINGS

Green buildings have both tangible and intangible benefits. The most tangible benefits are a reduction in water and energy consumption from day one of occupancy. Energy savings could be 20-30% and water savings 30-50%. The intangible benefits of new green buildings include enhanced air quality, excellent daylighting, health and well-being of the occupants, safety, and conservation of scarce national resources.

NATIONAL PRIORITIES ADDRESSED IN GREEN BUILDINGS

Green buildings address the most important national priorities of water conservation, waste handling, energy efficiency, reduced fossil fuel usage, lesser dependence on virgin material, and health and well-being of occupants.

Water Conservation

Most of the Asian countries are water stressed. In countries like India, water table has reduced drastically over the last decade. Green buildings encourage use of water in a self-sustainable manner, through reduce, recycle, and reuse strategies. By adopting green building concepts, the project can save potable water between 30-50%.

Consumer Waste Handling

Handling waste in buildings is difficult as most of the waste generated is not segregated at source and has a high probability of going to landfills. This is a challenge to the municipalities and Green buildings address this by encouraging segregation of the building waste.

Energy Efficiency

The building sector is a large consumer of electrical energy. Buildings can reduce energy consumption through energy efficient measures such as building envelope, lighting, air conditioning systems. Energy savings realised by adopting these measures can be between 2030%.

Reduced Use of Fossil Fuels

Fossil fuel is a slowly depleting resource the world over. Fossil fuel has been a major source of pollution in transportation, and so in green buildings, alternate fuel vehicles are encouraged for transportation.

Reduced Dependency on Virgin Materials

In green buildings, projects use recycled and reused materials and discourage virgin materials, thereby, addressing environmental impacts associated with extraction and processing of scare natural resources.

Health and Well-being of Occupants

Health and well-being of the occupants are the most important aspects of green buildings. Provision of adequate ventilation, daylight, and occupant well-being facilities are essential in a building as are the measures to minimise indoor air pollutants.

Some of the unique aspects addressed in green buildings include:

•Architectural excellence through integrated design approach

•Passive architectural features

•Structural design optimisation using steel and cement

•Water use reduction fin construction

•Use of certified green products—products that are evaluated right from extraction to disposal

•Regular monitoring of energy and water consumption data to facilitate performance monitoring and sustenance

IGBC Green Education

The rapid growth of green building movement has seen a surge in demand for trained professionals in design, construction, operation, and maintenance of green buildings. Apart from the building sector, building products and materials manufacturing industry, and technology suppliers are also looking for professionals trained in green building concepts to offer services to the green building sector.

To meet the growing demand of trained professionals in the construction and product manufacturing industry, IGBC has launched the Green Education Programme. The primary objective of the programme is to enable job-oriented and industry-ready students to enter the field of green built environment and facilitate academia-industry linkage.

As part of the programme, IGBC is offering various courses on green building concepts.

BENEFITS TO STUDENTS

•Accreditation as ‘IGBC AP - Associate’

•Exposure to green concepts in design, construction and operation of buildings

•Site visit to IGBC certified green buildings and practical experience

•Exposure to green building trends and technologies

•Knowledge of IGBC green building rating systems

•Excellent opportunity for placement in the industry

FOCUS AREAS

•Site selection and planning

•Water management

•Energy conservation

•Sustainable building materials and products

•Indoor environmental quality

CHAPTER

1 Site Selection and Planning

INTRODUCTION

All architectural projects have their origin in the sites they are located, and their conceptualisation, planning, designing and construction are site specific. Every site is unique and distinct, comprising numerous complex elements that include varying topography, flora and fauna, biodiversity, climate, physical, social, environmental features, culture, etc. which largely influence, impact, and guide design process and decision making.

Site is crucial in positioning and orienting the building, determining the footprints, form, shape, fabric, material, structure, sustainability, and typology of the building, and its relation with the neighbourhood buildings. Finding and locating an appropriate site for any project and analysing the site is vital for a project to be rational, effective, and relevant.

Architectural site analysis involves evaluating a particular location physically, environmentally, and socially. The aim is to develop an architectural solution of merit to achieve the project’s objective. Appropriate site is a pre-requisite that’s vital to developing a project of merit because all good architectural solutions have their genesis in understanding, appreciating and utilising the maximum out of the site.

Site is a major determinant of success and failure of a project, hence sourcing appropriate site is vital for the owner, project managers, and architects. Broad guidelines and principles must be kept in mind while defining/selecting sites for any sustainable architectural project. Since all human settlements are unique, defining precise site selection is complex. Important factors in searching for an appropriate site, the broad methodology, guideline and approach, are:

1. Site selection

2. Site ecology and ecological survey

3. Site planning

A. Analysis

B. Minimising disturbances to the site

C. Microclimate

D. Heat island effect

E. Erosion and sedimentation control

F. Exterior lighting

G. Facilities for differently able

1.1 SITE SELECTION

Site selection and planning affects decisions about the surrounding facilities and emphasises on relationships between built environment, ecosystems, and ecosystem services. It focuses on restoring project site elements, integrating the site with local and regional ecosystems, and preserving the biodiversity that natural systems rely on. Selecting sites that have low ecological impact i.e., brownfield sites/contaminated land, urban infill can save the farmlands and greenfield locations.

The aim of ideal site selection and planning is to minimise ecological degradation by designing buildings and systems that reduce the impact of earthworks, runoffs, construction pollution and ongoing operations.

1.1.1 LOCATION

Environmental and public health experts warn that an explosion in the number of motorised vehicles on India’s roads is threatening the health and economic security of its population. Vehicular emissions significantly contribute towards air pollution and greenhouse gas emissions.

Availability of water, sewerage, road network, storm water drains, communication network, etc. are vital for any project, institution, and user. While evaluating sites, these essentials must not be ignored. The absence of these services and infrastructures could delay the project and the initial, operational and maintenance costs could increase and make the project unaffordable. Only developed areas, where municipal services are available, must be considered for location of the project. Besides physical infrastructures, availability of social infrastructures in the close vicinity also need detailed evaluation. Success and failure of a project is largely governed by the availability of quality supportive infrastructure within and in the proximity.

1.1.2 BASIC AMENITIES

Basic amenities are essential for enhanced quality of life because they provide comfort, convenience and pleasure. Therefore, select a site for the project that is close to varied amenities or services such as schools, pharmacy, grocery/supermarket, post office. as listed in the compliance. To encourage the occupants to walk, there should be pedestrian access to these amenities without highways, walls, or other barriers blocking them.

Avoiding environmentally sensitive areas helps protect features that make many areas so special—creeks, lakes, aquifers, tree-covered hills, wildlife, native wildflowers and plants.

Fig. 1.1 Example - A project site with basic amenities in proximity

1.1.3 ACCESS TO PUBLIC TRANSPORTATION

India’s National Action Plan for Climate Change (NAPCC) recognises that GHG emissions from transport can be reduced by adopting a sustainability approach through a combination of measures, such as increased use of public transport, higher penetration of biofuels and enhanced energy efficiency of transport vehicles (NAPCC, GoI, 2008).

(a) Increasing the proximity of occupants to public transport during site selection: To reduce the impact of fossil fuel-based transportation, promote public transport and ensure that at least one mode of public transport is at a walkable distance (800m) to the building occupants.

(b) Provision of access to public transport: If public transport is not accessible, provision of shared vehicles (preferably alternate fuel vehicles like CNG and e-vehicles) from/to the nearest mode of public transport should be made available. Carpooling should be encouraged by providing incentives to the occupants, besides mass transit use.

(c) Encourage alternative modes of transport: To encourage the use of bicycles and alternative fuel vehicles, associated facilities like bicycle racks, e-charging facilities, reserved parking for e-vehicles, showers and lockers should be encouraged.

(d) Planning considerations: Service, pedestrian, and automobile paths need consolidated planning to minimise pavement costs, improve efficiencies, and centralised runoffs. Besides these, while planning road infrastructure, the roads, walkways and parking areas should be as compact as possible so that the ratio of impermeable surfaces to the gross site area can be reduced.

1.2 SITE ECOLOGY AND SURVEYS

Most of the developments impact the habitat and the local biodiversity of the site. Some of those impacts cause loss of habitats, reduction in the value of habitat or the ability of the habitat to support the species that depend on them.

An ecological site is a distinctive land with specific soil and physical characteristics that differ from other kinds of land in its ability to produce a distinctive kind and amount of vegetation and its ability to respond similarly to management actions and natural disturbances. Ecological surveys are carried out to identify species or habitats that exist on a particular site. They identify potential constraints to the development because of important habitats or species.

Early identification of ecological constraints ensures timely development of proposals and incorporation of mitigation measures into the design phase.

Purpose of ecological surveys

The purpose of undertaking ecological surveys is to:

•Assess under EIA Regulations

•Identify ecological constraints, if any, at an early stage

•Minimise impact on biodiversity

•Identify endangered or legally protected species and minimise or avoid any impact on them

•Appropriately design mitigation measures as per the site and the surrounding areas

1.3 SITE PLANNING

1.3.1 SITE AND CLIMATE ANALYSIS

Site analysis is an activity usually performed prior to the commencement of design, to determine site characteristics and develop the project design with minimum disturbance to the site features. The purpose of performing the analysis is to understand the prevailing site conditions and gather thorough information about the positive and negative factors affecting the site before starting the design. The information helps in developing design concepts, which further help in shaping a good relationship between the building and the site.

Site analysis involves study of the climate by analysing the sun path and wind patterns to locate the buildings at an ideal orientation on the site. The analysis further includes study of existing soil, topography, underground water levels, vegetation, etc.

The general design objectives for each climatic region are:

•Cold - The warming effect of solar radiation should be maximised and impact of winter wind minimised.

•Temperate - The warming effect of solar radiation should be maximised in winter and circulation of winter wind minimised. At the same time, shade should be maximised in summer while allowing air circulation.

•Hot-Arid - The design should focus on maximising shade and minimising the hot, dustladen winds.

•Hot-Humid - The design should focus on maximising shade and wind to reduce humidity.

1.3.2 SUN PATH

The sun path diagram helps determine the position of the sun at different times of the day throughout the year. It helps to understand if the sun is available on the site, on any orientation, during a particular time. The sun path analysis also helps understand the shading patterns on the site by the existing trees or buildings around the site, which would help in determining the building location and orientation.

Elements of Sun Path Diagram

The sun path diagram shows the path of the sun in the sky-dome as projected onto a horizontal surface.

•There is a different sun path diagram from every latitude.

•The lines running from east to west represent the path of the sun on 21 st day of each month of the year.

•Lines running perpendicular to the sun path lines indicate hours of the day.

•The lines radiating from the centre indicate the sun’s azimuth, i.e., the direction/angle of the sun.

•The concentric lines indicate the sun’s altitude. For example, at sunrise and sunset the sun’s altitude is zero, while it is maximum at 12 noon.

Fig. 1.2 Sun Path Diagram - Latitude 28o

How to read sun path diagram

To determine the sun’s position at 28oN latitude at 3pm in April,

1. Identify the month and time - Find the intersection of 3pm line and April line.

2. Find the azimuth - Follow the radial line that runs through the intersection and read azimuth of 260 o west of south

3. Find the altitude - Finally, follow the concentric ring that runs through the intersection and read the sun altitude of 45 o .

Dates, time, altitude and azimuth may all be interpolated between the values given.

1.3.3 WIND ROSE

It is important to locate the building in a particular orientation for continuous wind flow in the common areas and cross ventilation in the building. For this, wind direction and wind patterns on the site must be understood. This is possible through a wind rose diagram. Wind rose graphically represents the wind condition, direction and speed, at a given time and location. It shows the frequency of winds blowing from a particular direction.

Fig. 1.3 Wind rose plot of Chennai 1 January 2020 - 31 January 2020

•The wind rose diagram normally comprises 8 or 16 radiating spokes that represent the cardinal wind directions (north, east, south, west) and their intermediate directions.

•The concentric circles and thickness of the lines represent the frequency of the wind.

How to read wind rose diagram

1. Location - The location of the wind rose is mentioned at the top of the diagram along with time duration.

2. Legend - The coloured boxes represent the wind speeds listed next to it. These colours correspond to the colours on the spokes and tell the wind speed. Check the unit to see if it's