US EPA Kansas City Science & Technology Center. This facility features the following green attributes:
- LEED 2.0 Gold certified
- Green Power
- Native Landscaping
Green building (also known as green construction or sustainable building) refers to both a structure and the application of processes that are environmentally responsible and resource-efficient throughout a building's life-cycle: from planning to design, construction, operation, maintenance, renovation, and demolition. This requires close cooperation of the contractor, the architects, the engineers, and the client at all project stages.
The Green Building practice expands and complements the classical
building design concerns of economy, utility, durability, and comfort.
Leadership in Energy and Environmental Design
(LEED) is a set of rating systems for the design, construction,
operation, and maintenance of green buildings which was developed by the
U.S. Green Building Council.
Another certificate system that confirms the sustainability of
buildings is the British BREEAM (Building Research Establishment
Environmental Assessment Method) for buildings and large-scale
developments. Currently, World Green Building Council is conducting research on the effects of green buildings on the health and productivity of their users and is working with World Bank to promote Green Buildings in Emerging Markets through EDGE (Excellence in Design for Greater Efficiencies) Market Transformation Program and certification.[4] There are also other tools such as Green Star in Australia and the Green Building Index (GBI) predominantly used in Malaysia.
Building information modelling (BIM)
is a process involving the generation and management of digital
representations of physical and functional characteristics of places.
Building information models (BIMs) are files (often but not always in
proprietary formats and containing proprietary data) which can be
extracted, exchanged or networked to support decision-making regarding a
building or other built asset. Current BIM software is used by
individuals, businesses and government agencies who plan, design,
construct, operate and maintain diverse physical infrastructures, such
as water, refuse, electricity, gas, communication utilities, roads,
railways, bridges, ports and tunnels.
Although new technologies are constantly being developed to
complement current practices in creating greener structures, the common
objective of green buildings is 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
A similar concept is natural building, which is usually on a smaller scale and tends to focus on the use of natural materials that are available locally. Other related topics include sustainable design and green architecture.
Sustainability may be defined as meeting the needs of present
generations without compromising the ability of future generations to
meet their needs. Although some green building programs don't address the issue of retrofitting existing homes, others do, especially through public schemes for energy efficient refurbishment. Green construction principles can easily be applied to retrofit work as well as new construction.
A 2009 report by the U.S. General Services Administration
found 12 sustainably-designed buildings that cost less to operate and
have excellent energy performance. In addition, occupants were overall
more satisfied with the building than those in typical commercial
buildings. These are eco-friendly buildings.
Reducing environmental impact
Hanging gardens of One Central Park, Sydney
Globally, buildings are responsible for a huge share of energy,
electricity, water and materials consumption. The building sector has
the greatest potential to deliver significant cuts in emissions at
little or no cost. Buildings account for 18%
of global emissions today, or the equivalent of 9 billion tonnes of CO2
annually. If new technologies in construction are not adopted during
this time of rapid growth, emissions could double by 2050, according to
the United Nations Environment Program. Green building practices aim to reduce the environmental impact
of building. Since construction almost always degrades a building site,
not building at all is preferable to green building, in terms of
reducing environmental impact. The second rule is that every building
should be as small as possible. The third rule is not to contribute to sprawl, even if the most energy-efficient, environmentally sound methods are used in design and construction.
Buildings account for a large amount of land. According to the
National Resources Inventory, approximately 107 million acres
(430,000 km2) of land in the United States are developed. The International Energy Agency
released a publication that estimated that existing buildings are
responsible for more than 40% of the world’s total primary energy
consumption and for 24% of global carbon dioxide emissions.
Goals of green building
Blu Homes mkSolaire, a green building designed by Michelle Kaufmann.
Taipei 101, the tallest and largest green building of LEED Platinum certification in the world since 2011.
The concept of sustainable development can be traced to the energy (especially fossil oil) crisis and environmental pollution concerns of the 1960s and 1970s. The Rachel Carson book, “Silent Spring”,
published in 1962, is considered to be one of the first initial efforts
to describe sustainable development as related to green building. The green building movement in the U.S. originated from the need and desire for more energy efficient and environmentally friendly
construction practices. There are a number of motives for building
green, including environmental, economic, and social benefits. However,
modern sustainability initiatives call for an integrated and synergistic
design to both new construction and in the retrofitting of existing structures. Also known as sustainable design,
this approach integrates the building life-cycle with each green
practice employed with a design-purpose to create a synergy among the
practices used.
Green building brings together a vast array of practices,
techniques, and skills 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 equipment, and using plants and trees through green roofs, rain gardens,
and reduction of rainwater run-off. Many other techniques are used,
such as using low-impact building materials or using packed gravel or
permeable concrete instead of conventional concrete or asphalt to
enhance replenishment of ground water.
While the practices or technologies employed in green building
are constantly evolving and may differ from region to region,
fundamental principles persist from which the method is derived: siting
and structure design efficiency, energy efficiency, water efficiency,
materials efficiency, indoor environmental quality enhancement,
operations and maintenance optimization and waste and toxics reduction.
The essence of green building is an optimization of one or more of
these principles. Also, with the proper synergistic design, individual
green building technologies may work together to produce a greater
cumulative effect.
On the aesthetic side of green architecture or sustainable design
is the philosophy of designing a building that is in harmony with the
natural features and resources surrounding the site. There are several
key steps in designing sustainable buildings: specify 'green' building
materials from local sources, reduce loads, optimize systems, and
generate on-site renewable energy.
Life cycle assessment
A life cycle assessment (LCA) can help avoid a narrow outlook on environmental, social and economic concerns
by assessing a full range of impacts associated with all
cradle-to-grave stages of a process: from extraction of raw materials
through materials processing, manufacture, distribution, use, repair and
maintenance, and disposal or recycling. Impacts taken into account
include (among others) embodied energy, global warming potential, resource use, air pollution, water pollution, and waste.
In terms of green building, the last few years have seen a shift away from a prescriptive
approach, which assumes that certain prescribed practices are better
for the environment, toward the scientific evaluation of actual
performance through LCA.
Although LCA is widely recognized as the best way to evaluate the
environmental impacts of buildings (ISO 14040 provides a recognized LCA
methodology), it is not yet a consistent requirement of green building
rating systems and codes, despite the fact that embodied energy and
other life cycle impacts are critical to the design of environmentally
responsible buildings.
In North America, LCA is rewarded to some extent in the Green
Globes rating system, and is part of the new American National Standard
based on Green Globes, ANSI/GBI 01-2010: Green Building Protocol for Commercial Buildings.
LCA is also included as a pilot credit in the LEED system, though a
decision has not been made as to whether it will be incorporated fully
into the next major revision. The state of California also included LCA
as a voluntary measure in its 2010 draft Green Building Standards Code.
Although LCA is often perceived as overly complex and time
consuming for regular use by design professionals, research
organizations such as BRE in the UK and the Athena Sustainable Materials
Institute in North America are working to make it more accessible.
In the UK, the BRE Green Guide to Specifications offers ratings for 1,500 building materials based on LCA.
Siting and structure design efficiency
The foundation of any construction project is rooted in the concept and
design stages. The concept stage, in fact, is one of the major steps in a
project life cycle, as it has the largest impact on cost and
performance.
In designing environmentally optimal buildings, the objective is to
minimize the total environmental impact associated with all life-cycle
stages of the building project.
Exterior Light Shelves - Green Office Building, Denver Colorado
However,
building as a process is not as streamlined as an industrial process,
and varies from one building to the other, never repeating itself
identically. In addition, buildings are much more complex products,
composed of a multitude of materials and components each constituting
various design variables to be decided at the design stage. A variation
of every design variable may affect the environment during all the
building's relevant life-cycle stages.
Energy efficiency
An eco-house at Findhorn Ecovillage with a turf roof and solar panels
Green buildings often include measures to reduce energy consumption –
both the embodied energy required to extract, process, transport and
install building materials and operating energy to provide services such
as heating and power for equipment.
As high-performance buildings use less operating energy, embodied
energy has assumed much greater importance – and may make up as much as
30% of the overall life cycle energy consumption. Studies such as the
U.S. LCI Database Project
show buildings built primarily with wood will have a lower embodied
energy than those built primarily with brick, concrete, or steel.
To reduce operating energy use, designers use details that reduce
air leakage through the building envelope (the barrier between
conditioned and unconditioned space). They also specify high-performance
windows and extra insulation in walls, ceilings, and floors. Another
strategy, passive solar building design, is often implemented in low-energy homes. Designers orient windows and walls and place awnings, porches, and trees
to shade windows and roofs during the summer while maximizing solar
gain in the winter. In addition, effective window placement (daylighting) can provide more natural light and lessen the need for electric lighting during the day. Solar water heating further reduces energy costs.
Onsite generation of renewable energy through solar power, wind power, hydro power, or biomass
can significantly reduce the environmental impact of the building.
Power generation is generally the most expensive feature to add to a
building.
Water efficiency
Reducing water consumption and protecting water quality are key
objectives in sustainable building. One critical issue of water
consumption is that in many areas, the demands on the supplying aquifer
exceed its ability to replenish itself. To the maximum extent feasible,
facilities should increase their dependence on water that is collected,
used, purified, and reused on-site. The protection and conservation of
water throughout the life of a building may be accomplished by designing
for dual plumbing that recycles water in toilet flushing or by using
water for washing of the cars. Waste-water may be minimized by utilizing
water conserving fixtures such as ultra-low flush toilets and low-flow
shower heads. Bidets help eliminate the use of toilet paper, reducing
sewer traffic and increasing possibilities of re-using water on-site. Point of use water treatment
and heating improves both water quality and energy efficiency while
reducing the amount of water in circulation. The use of non-sewage and greywater for on-site use such as site-irrigation will minimize demands on the local aquifer.
Large commercial buildings with water and energy efficiency can
qualify for an LEED Certification. Philadelphia's Comcast Center is the
tallest building in Philadelphia. It's also one of the tallest buildings
in the USA that is LEED Certified. Their environmental engineering
consists of a hybrid central chilled water system which cools
floor-by-floor with steam instead of water. Burn's Mechanical set-up the
entire renovation of the 58 story, 1.4 million square foot sky scraper.
Materials efficiency
Building materials typically considered to be 'green' include lumber
from forests that have been certified to a third-party forest standard,
rapidly renewable plant materials like bamboo and straw, dimension stone, recycled stone, recycled metal, and other products that are non-toxic, reusable, renewable, and/or recyclable. For concrete a high performance or Roman self-healing concrete is available. The EPA (Environmental Protection Agency)
also suggests using recycled industrial goods, such as coal combustion
products, foundry sand, and demolition debris in construction projects. Energy efficient building materials and appliances are promoted in the United States through energy rebate programs.
Indoor environmental quality enhancement
The Indoor Environmental Quality (IEQ) category in LEED standards,
one of the five environmental categories, was created to provide
comfort, well-being, and productivity of occupants. The LEED IEQ
category addresses design and construction guidelines especially: indoor
air quality (IAQ), thermal quality, and lighting quality.
Indoor Air Quality seeks to reduce volatile organic compounds,
or VOCs, and other air impurities such as microbial contaminants.
Buildings rely on a properly designed ventilation system
(passively/naturally or mechanically powered) to provide adequate
ventilation of cleaner air from outdoors or recirculated, filtered air
as well as isolated operations (kitchens, dry cleaners, etc.) from other
occupancies. During the design and construction process choosing
construction materials and interior finish products with zero or low VOC
emissions will improve IAQ. Most building materials and
cleaning/maintenance products emit gases, some of them toxic, such as
many VOCs including formaldehyde. These gases can have a detrimental
impact on occupants' health, comfort, and productivity. Avoiding these
products will increase a building's IEQ. LEED, HQE and Green Star contain specifications on use of low-emitting interior. Draft LEED 2012 is about to expand the scope of the involved products. BREEAM
limits formaldehyde emissions, no other VOCs. MAS Certified Green is a
registered trademark to delineate low VOC-emitting products in the
marketplace.
The MAS Certified Green Program ensures that any potentially hazardous
chemicals released from manufactured products have been thoroughly
tested and meet rigorous standards established by independent
toxicologists to address recognized long term health concerns. These IAQ
standards have been adopted by and incorporated into the following
programs: (1) The United States Green Building Council (USGBC) in their
LEED rating system (2) The California Department of Public Health (CDPH) in their section 01350 standards (3) The Collaborative for High Performance Schools (CHPS) in their Best Practices Manual and (4) The Business and Institutional Furniture Manufacturers Association (BIFMA) in their level® sustainability standard.
Also important to indoor air quality is the control of moisture
accumulation (dampness) leading to mold growth and the presence of
bacteria and viruses as well as dust mites and other organisms and
microbiological concerns. Water intrusion through a building's envelope
or water condensing on cold surfaces on the building's interior can
enhance and sustain microbial growth. A well-insulated and tightly
sealed envelope will reduce moisture problems but adequate ventilation
is also necessary to eliminate moisture from sources indoors including
human metabolic processes, cooking, bathing, cleaning, and other
activities.
Personal temperature and airflow control over the HVAC system coupled with a properly designed building envelope
will also aid in increasing a building's thermal quality. Creating a
high performance luminous environment through the careful integration of
daylight and electrical light sources will improve on the lighting
quality and energy performance of a structure.
Solid wood products, particularly flooring, are often specified
in environments where occupants are known to have allergies to dust or
other particulates. Wood itself is considered to be hypo-allergenic and
its smooth surfaces prevent the buildup of particles common in soft
finishes like carpet. The Asthma and Allergy Foundation of America
recommends hardwood, vinyl, linoleum tile or slate flooring instead of
carpet. The use of wood products can also improve air quality by absorbing or releasing moisture in the air to moderate humidity.
Interactions among all the indoor components and the occupants
together form the processes that determine the indoor air quality.
Extensive investigation of such processes is the subject of indoor air
scientific research and is well documented in the journal Indoor Air.
Operations and maintenance optimization
No
matter how sustainable a building may have been in its design and
construction, it can only remain so if it is operated responsibly and
maintained properly. Ensuring operations and maintenance(O&M)
personnel are part of the project's planning and development process
will help retain the green criteria designed at the onset of the
project.
Every aspect of green building is integrated into the O&M phase of a
building's life. The addition of new green technologies also falls on
the O&M staff. Although the goal of waste reduction may be applied
during the design, construction and demolition phases of a building's
life-cycle, it is in the O&M phase that green practices such as
recycling and air quality enhancement take place. O&M staff should
aim to establish best practices in energy efficiency, resource
conservation, ecologically sensitive products and other sustainable
practices. Education of building operators and occupants is key to
effective implementation of sustainable strategies in O&M services.
Waste reduction
Green
architecture also seeks to reduce waste of energy, water and materials
used during construction. For example, in California nearly 60% of the
state's waste comes from commercial buildings During the construction phase, one goal should be to reduce the amount of material going to landfills.
Well-designed buildings also help reduce the amount of waste generated
by the occupants as well, by providing on-site solutions such as compost bins to reduce matter going to landfills.
To reduce the amount of wood that goes to landfill, Neutral
Alliance (a coalition of government, NGOs and the forest industry)
created the website dontwastewood.com. The site includes a variety of
resources for regulators, municipalities, developers, contractors,
owner/operators and individuals/homeowners looking for information on
wood recycling.
When buildings reach the end of their useful life, they are
typically demolished and hauled to landfills. Deconstruction is a method
of harvesting what is commonly considered "waste" and reclaiming it
into useful building material.
Extending the useful life of a structure also reduces waste – building
materials such as wood that are light and easy to work with make
renovations easier.
To reduce the impact on wells or water treatment plants, several options exist. "Greywater",
wastewater from sources such as dishwashing or washing machines, can be
used for subsurface irrigation, or if treated, for non-potable
purposes, e.g., to flush toilets and wash cars. Rainwater collectors are
used for similar purposes.
Centralized wastewater treatment systems can be costly and use a
lot of energy. An alternative to this process is converting waste and
wastewater into fertilizer, which avoids these costs and shows other
benefits. By collecting human waste at the source and running it to a
semi-centralized biogas
plant with other biological waste, liquid fertilizer can be produced.
This concept was demonstrated by a settlement in Lubeck Germany in the
late 1990s. Practices like these provide soil with organic nutrients and
create carbon sinks that remove carbon dioxide from the atmosphere, offsetting greenhouse gas emission. Producing artificial fertilizer is also more costly in energy than this process.
Reduce impact onto electricity network
Electricity networks are built based on peak demand (another name is peak load). Peak demand is measured in the units of watts (W). It shows how fast electrical energy is consumed. Residential electricity is often charged on electrical energy (kilowatt hour, kWh). Green buildings or sustainable buildings are often capable of saving electrical energy but not necessarily reducing peak demand.
When sustainable building features are designed, constructed and
operated efficiently, peak demand can be reduced so that there is less
desire for electricity network expansion and there is less impact onto
carbon emission and climate change.
These sustainable features can be good orientation, sufficient indoor
thermal mass, good insulation, photovoltaic panels, thermal or
electrical energy storage systems, smart building (home) energy
management systems.
Cost and payoff
The
most criticized issue about constructing environmentally friendly
buildings is the price. Photo-voltaics, new appliances, and modern
technologies tend to cost more money. Most green buildings cost a
premium of less than 2%, but yield 10 times as much over the entire life of
the building.
In regards to the financial benefits of green building, “Over 20
years, the financial payback typically exceeds the additional cost of
greening by a factor of 4-6 times. And broader benefits, such as
reductions in greenhouse gases (GHGs) and other pollutants have large
positive impacts on surrounding communities and on the planet.” The stigma is between the knowledge of up-front cost
vs. life-cycle cost. The savings in money come from more efficient use
of utilities which result in decreased energy bills. It is projected
that different sectors could save $130 billion on energy bills.
Also, higher worker or student productivity can be factored into savings and cost deductions.
Numerous studies have shown the measurable benefit of green
building initiatives on worker productivity. In general it has been
found that, "there is a direct correlation between increased
productivity and employees who love being in their work space.”
Specifically, worker productivity can be significantly impacted by
certain aspects of green building design such as improved lighting,
reduction of pollutants, advanced ventilation systems and the use of
non-toxic building materials. In “The Business Case for Green Building”,
the U.S. Green Building Council gives another specific example of how
commercial energy retrofits increase worker health and thus
productivity, “People in the U.S. spend about 90% of their time indoors.
EPA studies indicate indoor levels of pollutants may be up to ten times
higher than outdoor levels. LEED-certified buildings are designed to
have healthier, cleaner indoor environmental quality, which means health
benefits for occupants."
Studies have shown over a 20-year life period, some green buildings have yielded $53 to $71 per square foot back on investment.
Confirming the rentability of green building investments, further
studies of the commercial real estate market have found that LEED and
Energy Star certified buildings achieve significantly higher rents, sale
prices and occupancy rates as well as lower capitalization rates
potentially reflecting lower investment risk.
Regulation and operation
As
a result of the increased interest in green building concepts and
practices, a number of organizations have developed standards, codes and
rating systems that let government regulators, building professionals
and consumers embrace green building with confidence. In some cases,
codes are written so local governments can adopt them as bylaws to
reduce the local environmental impact of buildings.
Green building rating systems such as BREEAM (United Kingdom),
LEED (United States and Canada), DGNB (Germany), CASBEE (Japan), and
VERDEGBCe (Spain), GRIHA (India) help consumers determine a
structure’s level of environmental performance. They award credits for
optional building features that support green design in categories such
as location and maintenance of building site, conservation of water,
energy, and building materials, and occupant comfort and health. The
number of credits generally determines the level of achievement.
Green building codes and standards, such as the International Code Council’s draft International Green Construction Code,
are sets of rules created by standards development organizations that
establish minimum requirements for elements of green building such as
materials or heating and cooling.
Some of the major building environmental assessment tools currently in use include:
- United States: International Green Construction Code (IGCC)
International frameworks and assessment tools
IPCC Fourth Assessment Report
Climate Change 2007, the Fourth Assessment Report (AR4) of the United Nations Intergovernmental Panel on Climate Change (IPCC),
is the fourth in a series of such reports. The IPCC was established by
the World Meteorological Organization (WMO) and the United Nations
Environment Programme (UNEP) to assess scientific, technical and
socio-economic information concerning climate change, its potential
effects and options for adaptation and mitigation.
UNEP and Climate change
United Nations Environment Program UNEP
works to facilitate the transition to low-carbon societies, support
climate proofing efforts, improve understanding of climate change
science, and raise public awareness about this global challenge.
GHG Indicator
The Greenhouse Gas Indicator: UNEP Guidelines for Calculating
Greenhouse Gas Emissions for Businesses and Non-Commercial Organizations
Agenda 21
Agenda 21
is a programme run by the United Nations (UN) related to sustainable
development. It is a comprehensive blueprint of action to be taken
globally, nationally and locally by organizations of the UN,
governments, and major groups in every area in which humans impact on the environment. The number 21 refers to the 21st century.
FIDIC's PSM
The International Federation of Consulting Engineers (FIDIC)
Project Sustainability Management Guidelines were created in order to
assist project engineers and other stakeholders in setting sustainable
development goals for their projects that are recognized and accepted by
as being in the interests of society as a whole. The process is also
intended to allow the alignment of project goals with local conditions
and priorities and to assist those involved in managing projects to
measure and verify their progress.
The Project Sustainability Management Guidelines are structured
with Themes and Sub-Themes under the three main sustainability headings
of Social, Environmental and Economic. For each individual Sub-Theme a
core project indicator is defined along with guidance as to the
relevance of that issue in the context of an individual
project.
The Sustainability Reporting Framework provides guidance for
organizations to use as the basis for disclosure about their
sustainability performance, and also provides stakeholders a universally
applicable, comparable framework in which to understand disclosed
information.
The Reporting Framework contains the core product of the
Sustainability Reporting Guidelines, as well as Protocols and Sector
Supplements.
The Guidelines are used as the basis for all reporting. They are the
foundation upon which all other reporting guidance is based, and outline
core content for reporting that is broadly relevant to all
organizations regardless of size, sector, or location. The Guidelines
contain principles and guidance as well as standard disclosures –
including indicators – to outline a disclosure framework that
organizations can voluntarily, flexibly, and incrementally, adopt.
Protocols underpin each indicator in the Guidelines and include
definitions for key terms in the indicator, compilation methodologies,
intended scope of the indicator, and other technical references.
Sector Supplements respond to the limits of a one-size-fits-all
approach. Sector Supplements complement the use of the core Guidelines
by capturing the unique set of sustainability issues faced by different
sectors such as mining, automotive, banking, public agencies and others.
IPD Environment Code
The IPD Environment Code
was launched in February 2008. The Code is intended as a good practice
global standard for measuring the environmental performance of corporate
buildings. Its aim is to accurately measure and manage the
environmental impacts of corporate buildings and enable property
executives to generate high quality, comparable performance information
about their
buildings anywhere in the world. The Code covers a wide range of
building types (from offices to airports) and aims to inform and support
the following;
- Creating an environmental strategy
- Inputting to real estate strategy
- Communicating a commitment to environmental improvement
- Creating performance targets
- Environmental improvement plans
- Performance assessment and measurement
- Life cycle assessments
- Acquisition and disposal of buildings
- Supplier management
- Information systems and data population
- Compliance with regulations
- Team and personal objectives
IPD estimate that it will take approximately three years to gather
significant data to develop a robust set of baseline data that could be
used across a typical corporate estate.
ISO 21931
ISO/TS 21931:2006, Sustainability in building
construction—Framework for methods of assessment for environmental
performance of construction works—Part 1: Buildings, is intended to
provide a general framework for improving the quality and comparability
of methods for assessing the environmental performance of buildings. It
identifies and describes issues to be taken into account when using
methods for the assessment of environmental performance for new or
existing building properties in the design, construction, operation,
refurbishment and deconstruction stages. It is not an assessment system
in itself but is intended be used in conjunction with, and following the
principles set out in, the ISO 14000 series of standards.
