Green building, also called green construction, sustainable building, or eco-friendly building, means creating structures and using methods that protect the environment and use resources wisely throughout a building's life. This includes planning, designing, building, operating, maintaining, repairing, and tearing down the building. It needs teamwork between the contractor, architects, engineers, and the building owner at every step. Green building adds to traditional ideas about building design, such as cost, usefulness, lasting quality, and comfort. It also means saving resources like energy, land, water, and materials during the building's entire life. This helps protect the environment, reduces pollution, gives people healthy and comfortable spaces, and works with nature. Green building technology focuses on using less and getting more from resources, being cost-effective, protecting the environment, and combining different systems to work better together.

Leadership in Energy and Environmental Design (LEED) is a system that rates how green a building is during its design, construction, use, and maintenance. It was created by the U.S. Green Building Council. The Green Building Initiative (GBI) is an organization approved by the American National Standards Institute (ANSI) that provides tools to assess and certify green buildings, such as Green Globes. Other systems that check how sustainable buildings are include BREEAM from the UK, which rates buildings and large developments, and DGNB from Germany, which measures how well buildings, indoor spaces, and areas meet sustainability goals. The World Green Building Council is studying how green buildings affect the health and productivity of people who use them. It works with the World Bank to help countries build greener structures through programs like EDGE, which improves efficiency. Other tools used in different countries include NABERS and Green Star in Australia, GSAS in the Middle East, and GBI in Malaysia.

Building information modeling (BIM) is a process that creates and manages computer models showing the physical and functional details of places. These models, called BIMs, are files (often in special formats) that can be shared or used online to help make decisions about buildings or other structures. BIM software is used by people, companies, and government groups to plan, design, build, and maintain different types of infrastructure, such as water systems, waste management, electricity, gas, communication networks, roads, trains, bridges, ports, and tunnels.

Even though new technologies are being developed to help build greener structures, the main goal of green buildings is to reduce the harm that buildings cause to human health and the environment. This includes using natural materials, focusing on sustainability, and making sure buildings work well with nature. Sustainability means meeting the needs of today without harming the ability of future generations to meet their needs. Some green building programs do not help update old buildings, but others do, especially through public programs that improve energy efficiency in older homes. Green building ideas can be used for both new buildings and updating old ones.

A 2009 report by the U.S. General Services Administration found that 12 buildings designed with sustainability in mind cost less to operate and used energy efficiently. People who worked in these buildings were also more satisfied than those in regular office buildings. These are examples of eco-friendly buildings.

Reducing environmental impact

Buildings use a large amount of energy, electricity, water, and materials. In 2020, they made up 37% of the world’s energy use and 33% of global carbon dioxide emissions, according to the United Nations. When including the production of building materials, emissions reached 39%. If new construction technologies are not used during this time of fast growth, emissions could double by 2050, as reported by the United Nations Environment Program.

Glass buildings, especially large all-glass skyscrapers, contribute to climate change because they are not energy efficient. These buildings look attractive and let in a lot of natural light, but they also trap heat. This causes more use of air conditioning, which increases carbon emissions. Experts suggest changing building designs and possibly limiting the use of all-glass buildings to reduce their negative impact on the environment.

Buildings take up a lot of land. In the United States, about 107 million acres (430,000 km²) are developed, according to the National Resources Inventory. The International Energy Agency estimates that existing buildings use more than 40% of the world’s total energy and produce 24% of global carbon dioxide emissions.

A 2016 report stated that buildings use more than 30% of all energy produced. The report explained that if action is taken to improve building energy efficiency, building energy use could stay near current levels under a plan to limit global temperature rise to below 2°C. This would reduce the average energy use of buildings worldwide by more than 80% by 2050.

Green building practices aim to reduce the environmental harm caused by buildings, as the building sector has the most potential to cut emissions with little or no cost. Key guidelines include: making buildings as small as possible, avoiding land use that spreads out over large areas, even if energy-efficient methods are used. Bioclimatic design uses local climate conditions to create comfortable indoor environments while saving energy. This might involve changing a building’s shape or orienting it to face south to maximize sunlight for energy or lighting. Even in cities with planned construction, bioclimatic design can still help reduce environmental impact.

Goals of green building

The idea of sustainable development started during the energy crisis and environmental pollution problems of the 1960s and 1970s. The book Silent Spring by Rachel Carson, published in 1962, is seen as one of the first works to connect sustainable development with green building. The green building movement in the United States began because people wanted more energy-efficient and environmentally friendly construction methods. Reasons for building green include environmental, economic, and social benefits. Modern sustainability efforts focus on combining different design approaches for both new buildings and older ones being updated. This method, also called sustainable design, connects the building’s life cycle with each green practice used to create a working relationship between these practices.

Green building uses many practices, techniques, and skills to reduce or stop the harm buildings cause to the environment and human health. It often uses renewable resources, such as sunlight through passive solar, active solar, and photovoltaic equipment, and plants and trees through green roofs, rain gardens, and reducing rainwater runoff. Other methods include using low-impact building materials or permeable concrete instead of traditional concrete or asphalt to help groundwater refill.

Although green building practices and technologies change over time and vary by region, basic principles remain the same. These include efficient site and structure design, energy efficiency, water efficiency, material efficiency, improving indoor environmental quality, optimizing operations and maintenance, and reducing waste and toxins. The main goal of green building is to improve one or more of these principles. With the right design, individual green technologies can work together to create a bigger positive effect.

On the design side, green architecture or sustainable design aims to create buildings that work well with the natural features and resources around them. Key steps in designing sustainable buildings include using locally sourced "green" building materials, reducing energy and resource use, optimizing systems, and generating renewable energy on-site.

A life cycle assessment (LCA) helps avoid looking at environmental, social, and economic issues narrowly by evaluating all stages of a process, from raw material extraction to disposal or recycling. Impacts considered include embodied energy, global warming potential, resource use, air and water pollution, and waste.

In recent years, green building has moved away from a prescriptive approach, which assumes certain practices are better for the environment, toward using LCA to scientifically evaluate actual performance.

Although LCA is widely accepted as the best way to assess environmental impacts (as outlined in ISO 14040), it is not always required by green building rating systems or codes, even though factors like embodied energy are important for environmentally responsible buildings.

In North America, LCA is included in the Green Globes rating system and part of the ANSI/GBI 01-2010 standard. It is also a pilot credit in the LEED system, though it may not be fully included in future updates. California’s 2010 draft Green Building Standards Code includes LCA as a voluntary measure.

Despite being seen as complex and time-consuming, research groups like BRE in the UK and the Athena Sustainable Materials Institute in North America are working to make LCA easier for design professionals. In the UK, the BRE Green Guide to Specifications rates 1,500 building materials based on LCA.

The start of any construction project is the concept and design stages, which have the biggest impact on cost and performance. Designing environmentally optimal buildings aims to reduce the total environmental impact across all stages of a building’s life.

Building processes are not as simple or repetitive as industrial processes, and each building is unique, made of many materials and components with different design choices. Changes in these choices can affect the environment during all stages of a building’s life.

Green buildings often include steps to reduce energy use, both the energy needed to create, transport, and install materials (embodied energy) and the energy used for services like heating and power. As buildings use less operating energy, embodied energy has become more important, sometimes making up 30% of a building’s total life cycle energy use. Studies show that buildings made mostly of wood have lower embodied energy than those made mostly of brick, concrete, or steel.

To reduce operating energy, designers use details that minimize air leakage through the building envelope, specify high-performance windows, and add extra insulation. Passive solar building design is often used in low-energy homes, with windows and walls placed to maximize sunlight in winter and reduce heat in summer. Effective window placement (daylighting) can provide natural light and reduce the need for electric lighting. Solar water heating also lowers energy costs.

Generating renewable energy on-site, such as through solar, wind, hydro, or biomass power, can greatly reduce a building’s environmental impact. Power generation is usually the most expensive feature to add.

Energy efficiency for green buildings can be evaluated using numerical or non-numerical methods, such as simulation modeling and analytical tools.

In a 2024 report, the International Energy Agency (IEA) stated that buildings account for about 30% of global energy use and over 50% of electricity demand. It noted that heat pump sales tripled from 2015 to 2022, electric cars made up 20% of 2023 vehicle sales, and China’s peak electricity demand could double by mid-century. India’s air conditioner ownership could increase tenfold by 2050, raising peak electricity demand sixfold, but efficient practices could cut this in half. By 2050, demand response measures might reduce household electricity bills by 7% to 12% in advanced economies and nearly 20% in developing ones, with smart device installations nearly doubling by 2030. The U.S. could see a 116 GW reduction in energy use through these efforts.

Cost and payoff

The most common concern about building environmentally friendly structures is the cost. Solar panels, new appliances, and modern technology often cost more money. However, most green buildings cost only about 2% more to build, but they save 10 times that amount over the building's entire life. Studies show that over 20 years, the financial savings from green buildings usually cover the extra cost 4 to 6 times. In addition, green buildings help reduce harmful gases and pollutants, which benefits communities and the environment. The challenge is understanding the difference between the initial cost and the long-term savings. Lower energy bills result from using utilities more efficiently, which saves money. It is estimated that different industries could save $130 billion on energy costs over time. Also, workers and students may be more productive in green buildings, which adds to the savings.

Research has shown that green buildings can improve worker productivity. Studies indicate that employees are more productive when they enjoy their work environment. Specific features of green buildings, such as better lighting, fewer pollutants, improved ventilation, and non-toxic materials, can greatly affect productivity. In "The Business Case for Green Building," the U.S. Green Building Council explains that commercial buildings that use energy-saving upgrades can improve worker health and productivity. People in the United States spend about 90% of their time indoors. Studies by the Environmental Protection Agency (EPA) show that indoor air can have up to 10 times more pollutants than outdoor air. Buildings with LEED certification are designed to have cleaner and healthier indoor air, which benefits people who live or work there.

Over a 20-year period, some green buildings have returned $53 to $71 for every square foot of space. Studies of the commercial real estate market also show that buildings with LEED or Energy Star certifications often have higher rents, sale prices, and occupancy rates. These buildings also have lower investment risks, which makes them more attractive to buyers and investors.

Regulation and operation

Because more people are interested in green building ideas, many groups have created rules, standards, and systems to help governments, builders, and people who use buildings. In some cases, these rules can become local laws to help reduce the harm buildings cause to the environment.

Green building systems like BREEAM (United Kingdom), LEED (United States and Canada), DGNB (Germany), CASBEE (Japan), VERDE (Spain), and GRIHA (India) help people see how well a building protects the environment. These systems give points for optional features that support green building, such as how a building is placed and kept, saving water, using less energy, choosing better materials, and improving comfort and health for people inside. The number of points usually shows how well a building performs.

Green building rules and standards, like the International Code Council's draft International Green Construction Code, are sets of rules made by groups that create standards. These rules set the minimum requirements for parts of green building, such as the materials used or how heating and cooling systems work.

The new version of the European Construction Products Regulation (PCR) includes parts about studying how a product affects the environment over its whole life and checking Environmental Product Declarations using the "System 3+" process.

Some of the main tools used to assess building environmental performance include:

• United States: International Green Construction Code (IGCC)

Green neighborhoods and villages

At the start of the 21st century, efforts were made to apply the ideas of green building, not only for single buildings but also for neighborhoods and villages. The goal was to create neighborhoods and villages that produce all the energy they need on their own. These areas would also reuse waste, use transportation that does not harm the environment, and grow their own food. Green villages are seen as a way to spread out sustainable practices for the climate. This approach may be especially helpful in places with many rural or scattered villages, such as India, where 74% of the population lives in more than 600,000 villages.

International frameworks and assessment tools

The 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 reports. The IPCC was created by the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to examine scientific, technical, and socio-economic information about climate change, its possible effects, and ways to adapt to or reduce its impacts.

UNEP and Climate Change

The United Nations Environment Programme (UNEP) works to help societies move toward lower carbon emissions, support efforts to prepare for climate impacts, improve understanding of climate science, and increase public awareness about climate change.

The Greenhouse Gas Indicator: UNEP Guidelines for Calculating Greenhouse Gas Emissions for Businesses and Non-Commercial Organizations

Agenda 21 is a program led by the United Nations (UN) focused on sustainable development. It is a detailed plan for action to be taken globally, nationally, and locally by UN organizations, governments, and major groups in all areas where human activity affects the environment. The number 21 refers to the 21st century.

The International Federation of Consulting Engineers (FIDIC) Project Sustainability Management Guidelines were developed to help project engineers and other stakeholders set sustainability goals for their projects that benefit society. The process also aims to match project goals with local conditions and priorities and help project managers measure and track their progress.

The Project Sustainability Management Guidelines are organized under three main sustainability areas: Social, Environmental, and Economic. Each sub-topic includes a core project indicator and guidance on how that issue relates to a specific project.

The Sustainability Reporting Framework provides guidance for organizations to share information about their sustainability performance. It also gives stakeholders a consistent and comparable way to understand reported information.

The Reporting Framework includes the main product of the Sustainability Reporting Guidelines, along with Protocols and Sector Supplements. The Guidelines are the foundation for all reporting. They outline essential content for reporting that applies broadly to all organizations, regardless of size, industry, or location. The Guidelines include principles, guidance, and standard disclosures—such as indicators—to help organizations voluntarily and flexibly share information about their sustainability efforts.

Protocols support each indicator in the Guidelines and include definitions for key terms, methods for collecting data, the scope of each indicator, and other technical details.

Sector Supplements address the limitations of a single approach for all industries. They complement the core Guidelines by highlighting unique sustainability challenges faced by different sectors, such as mining, automotive, banking, public agencies, and others.

The IPD Environment Code was introduced in February 2008. The Code is a global standard for measuring the environmental performance of corporate buildings. Its goal is to accurately measure and manage the environmental impacts of corporate buildings and help property managers create high-quality, comparable information about building performance worldwide. The Code applies to many building types, including offices and airports, and supports the following:

• Creating an environmental strategy
• Contributing to real estate strategy
• Communicating a commitment to environmental improvement
• Setting performance targets
• Developing environmental improvement plans
• Assessing and measuring performance
• Conducting life cycle assessments
• Managing building acquisitions and disposals
• Managing suppliers
• Using information systems and data
• Complying with regulations
• Setting team and personal goals

IPD estimates it will take about three years to collect enough data to create a reliable set of baseline information for a typical corporate building estate.

ISO/TS 21931:2006, Sustainability in Building Construction—Framework for Methods of Assessment for Environmental Performance of Construction Works—Part 1: Buildings, provides a general framework to improve the quality and comparability of methods for assessing the environmental performance of buildings. It identifies and explains factors to consider when evaluating the environmental performance of new or existing buildings during design, construction, operation, renovation, and demolition. It is not an assessment system itself but is meant to be used with the principles outlined in the ISO 14000 series of standards.

Development history

• In the 1930s, Iceland began using geothermal hot water to heat homes in a district.
• In the 1960s, American architect Paul Soleri introduced a new idea for eco-friendly building designs.
• In 1969, American architect Ian McHarg wrote the book Design Integrates Nature, which officially started the field of ecological architecture.
• In the 1970s, the energy crisis led to the development of energy-saving technologies like solar, geothermal, and wind energy. Energy-efficient buildings became a major focus for building development.
• In 1975, the Swiss PLENAR-group shared the idea of energy-efficient homes in the publication PLENAR: Planning-Energy-Architecture.
• In 1980, the World Conservation Organization first used the term "sustainable development." At the same time, energy-saving building systems improved and were widely used in countries like Germany, Britain, France, and Canada.
• In 1982, Per and Maria Krusche shared an eco-friendly approach to architecture in Ökologisches Bauen (ecological buildings) for the German Federal Environment Agency.
• In 1987, the United Nations Environment Program released the report Our Common Future, which defined the concept of sustainable development.
• In 1990, the United Kingdom released the world’s first green building standard.
• In 1992, the United Nations Conference on Environment and Development promoted sustainable development, making green buildings a key direction for future building projects.
• In 1993, the United States created the Green Building Association.
• In 1996, Hong Kong introduced green building standards.
• In 1999, Taiwan introduced green building standards.
• In 2000, Canada introduced green building standards.
• In 2005, Singapore started the "BCA Green Building Mark" program.
• In 2015, China implemented the "Green Building Evaluation Standards," according to the Berkeley National Laboratory.
• In 2021, the first low-cost and sustainable 3D-printed house made from a clay mixture was completed.

Green building by country

• Green Building Practices in Australia
• Green Building Practices in Bangladesh
• Green Building Practices in Germany
• Green Building Practices in France
• Green Building Practices in Israel
• Green Building Practices in South Africa
• Green Building Practices in the United Kingdom
• Green Building Practices in India
• Green Building Practices in the United States
• Green Building Practices in Canada
• The Model Home 2020 Project: Denmark, Austria, Germany, France, and the United Kingdom