Green Building, Ecological Footprint & LCA

1. Green buildings

A green building reduces negative impacts on the environment over its whole life — design, construction, operation, maintenance and demolition.

Rating systems

2. Ecological footprint

• Biocapacity — the planet's (or a country's) capacity to supply these resources.
• If footprint > biocapacity → ecological deficit / overshoot.
• Humanity currently uses the resources of roughly 1.7 Earths a year (Global Footprint Network).
• Earth Overshoot Day — the date each year when humanity's demand exceeds what Earth can regenerate that year (falls around late July–early August in recent years).
• Carbon footprint — total greenhouse-gas emissions (as CO₂-equivalent) caused by a person, product or organisation; the largest part of the ecological footprint.
• Water footprint — total fresh water used, directly and indirectly (blue, green and grey water).

Green building concept

A green building is one that, throughout its life cycle (siting, design, construction, operation, maintenance, renovation and demolition), reduces or eliminates negative impacts on the environment and occupants, and uses resources efficiently — energy, water, materials and land — while providing a healthy indoor environment.

Benefits

Principles and strategies

1. Sustainable site planning

• Avoid ecologically sensitive land; preserve topsoil, trees and natural drainage.
• Reduce heat island effect — shading, vegetation, high solar reflectance index (SRI) roofs and paving, green roofs.
• Access to public transport, cycling; limit parking footprint.
• Erosion and sediment control during construction.

2. Water efficiency

• Low-flow fixtures (dual-flush WCs, aerators, sensor taps).
• Rainwater harvesting — storage and/or groundwater recharge.
• Wastewater treatment and recycling — treated water for flushing, landscaping, cooling towers.
• Efficient landscaping — native, drought-tolerant plants; drip irrigation.
• Metering of water use.

3. Energy efficiency

Passive design (reduce demand first):

• Orientation — longer facades facing north and south in hot climates in India (to reduce east–west solar gain).
• Shading — overhangs, louvres, fins, vegetation.
• Insulation of roofs and walls; high-performance glazing (low SHGC, low U-value); optimum window-to-wall ratio.
• Daylighting — light shelves, skylights; natural ventilation — cross-ventilation, stack effect, courtyards.
• Thermal mass, cool roofs, evaporative cooling, earth air tunnels.

Active systems:

• Efficient HVAC (high COP chillers, VRF, variable speed drives), LED lighting with controls (occupancy/daylight sensors).
• Building management systems (BMS) and metering.
• Renewable energy — rooftop solar PV, solar water heating.

4. Materials and resources

• Low embodied energy and local/regional materials.
• Recycled content — fly ash bricks and cement (PPC), GGBS, recycled aggregates, recycled steel.
• Rapidly renewable materials (bamboo), certified wood.
• Construction and demolition waste management — reuse, recycling.
• Durable, low-maintenance materials; modular and prefabricated construction to reduce waste.

5. Indoor environmental quality (IEQ)

• Adequate fresh air ventilation; control of CO₂.
• Low-VOC paints, adhesives and sealants; no asbestos or CFC-based materials.
• Thermal comfort, daylight and views, acoustic comfort.
• Tobacco smoke control.

6. Waste management

• Segregation at source, composting of organic waste, recycling during operation.

Embodied energy and life cycle assessment

• Embodied energy — total energy used to extract, manufacture, transport and install a material (e.g. aluminium and steel have high embodied energy per kg; timber, stone and earth are low).
• Operational energy — energy used during building use (lighting, HVAC, appliances); usually the major share over life for conventional buildings.
• Life cycle assessment (LCA) evaluates environmental impacts over all life stages ("cradle to grave").
• Embodied carbon is gaining attention as operational energy is reduced.

Green building rating systems

GRIHA (India)

• Green Rating for Integrated Habitat Assessment — India's national rating system, developed by TERI (The Energy and Resources Institute) and supported by the Ministry of New and Renewable Energy (MNRE); administered by the GRIHA Council.
• Evaluates buildings on criteria covering site planning, energy, water, materials, waste, health and well-being, social aspects, and more — scored out of 100 points with additional innovation points, and some mandatory criteria.
• Rating from 1 to 5 stars according to points achieved (a minimum score of about 25 is needed for 1 star; the highest band is 5 stars).
• SVAGRIHA — simplified version for small projects (smaller built-up areas); other variants exist for large developments, cities and existing buildings.
• Several government bodies have promoted or required GRIHA ratings for public buildings.

IGBC (India)

• Indian Green Building Council, part of the Confederation of Indian Industry (CII), formed in 2001.
• Rating systems for new buildings, homes, factories, townships, cities, existing buildings, net zero buildings and others.
• Certification levels: Certified, Silver, Gold, Platinum (some systems also have Super Platinum).
• The CII–Sohrabji Godrej Green Business Centre, Hyderabad was the first building in India to receive LEED Platinum rating (2003).

LEED (international)

• Leadership in Energy and Environmental Design, developed by the US Green Building Council (USGBC).
• Categories include location and transportation, sustainable sites, water efficiency, energy and atmosphere, materials and resources, indoor environmental quality, innovation, regional priority.
• LEED v4/v4.1 (out of 110 points) levels:

Other systems

• BREEAM (UK, Building Research Establishment) — among the earliest (1990).
• Green Star (Australia), CASBEE (Japan), DGNB (Germany).
• EDGE (Excellence in Design for Greater Efficiencies) — by the IFC (World Bank Group), requiring savings in energy, water and embodied energy in materials.