What are green buildings?
Green buildings incorporate measures that are environmentally friendly and resource-efficient across the building lifecycle. The green buildings concept aims to comprehensively minimize the negative impact and maximize the positive impact a building has on its natural environment and human occupants.
As a holistic approach to their planning, design, construction, operation, and maintenance, green buildings successfully maximize the natural efficiencies of a building site and integrate them with renewable and low-carbon technologies to support the building’s energy needs and create a healthy built environment. Areas of priority in green buildings include the efficient use of energy, water, and other resources; quality of the indoor environment; and impacts to the natural environment.
Buildings and the supply chain that supports them are responsible for an enormous share of worldwide carbon dioxide emissions—also referred to as greenhouse gases—and energy, water, and materials consumption. The global building sector also represents the largest opportunity for significant, cost-effective improvements in these areas, making it a broad and robust focus of research and development efforts.
Understanding the nature and extent of inefficiencies and negative impacts in the built environment helps drive the development of new approaches and technologies that can improve all aspects of a building’s performance. Green buildings are needed on a global scale to help drastically reduce greenhouse gas emissions, conserve increasingly stretched energy resources, and contribute to improved human health.
A history of green buildings
The concept of ecological architecture was introduced in the 1960s. The energy crisis in the 1970s further fueled the development of renewable energy resources, including solar, geothermal, and wind energy, as well as more energy-efficient buildings. In 1980, the concept of “sustainable development” took hold, and a few developed countries had begun widely implementing energy-saving building systems. In 1990, the United Kingdom introduced the world’s first green building standard, followed by formation of the U.S. Green Building Council in 1993.
The U.S. Green Building Council established the Leadership in Energy and Environmental Design (LEED) green building rating system later in the 1990s to create a central framework for codifying and verifying the effective implementation of green building practices. It has grown into a robust and internationally recognized standard, despite its origination and predominant application in the United States.
Since the 1990s, agencies and countries around the world also have adopted their own green building programs and standards. Regardless of the system for guiding its implementation, the green buildings concept remains universal. It has evolved into a necessary cornerstone in the building sector and a major focus of academia and industry in seeking to address global energy challenges.
Green buildings importance and applications
Buildings account for about 40 percent of our nation’s energy use and consume 75 percent of our nation’s electricity. The building sector accounts for more than one third of global energy-related greenhouse gas emissions, a percentage that could substantially increase over the years ahead without additional intervention. There are significant opportunities to improve the way buildings function, and the mounting pressure on our energy resources and environment has necessitated robust investment and effort to maximize them.
Green buildings combine a variety of approaches—to practices, technologies, and materials—across all stages of a building’s lifecycle. The set of measures applied to a building is customized to that building’s unique situation and work together to optimally reduce its impact on the human and natural environment.
Many of these approaches involve using renewable resources, as well as introducing techniques and technologies or using innovative materials that improve resource utilization. Maximizing energy, water, and materials performance are major drivers in configuring green buildings. The following examples are just a few of many options in the green builder’s toolbox, a list of measures that continues to grow and evolve with new knowledge and innovation.
Renewable energy sources, including solar, are often factored into green buildings. For example, some use photovoltaic panels for on-site solar power generation. Others employ passive solar building design strategies that physically position building elements, including windows, walls, awnings, and landscaping, to maximize the benefits of cooling shade in summer and solar warmth in winter. The concept of daylighting calls for orienting windows in a manner that makes best use of natural light inside the building and reduces electric lighting needs. And solar-powered water heating cuts down on energy costs.
Plants and trees have also become firmly rooted within green building practices. They are used to create a form of “green roof” that helps manage rainwater, provides building insulation, and cools nearby urban air, among other benefits. They are also planted in “rain gardens” to filter pollution from stormwater runoff, allowing it to be redirected in various useful ways that ultimately conserve water and ease related infrastructure and environmental burdens.
The discovery and refinement of these and many other measures, including energy-efficient technologies across the building system, continues to inform and improve industry standards, codes, and rating systems used by government, building professionals, and consumers. This includes LEED and other guidance structures around the world.
As a notable example, LEED certification is now universally recognized as distinguishing a building’s performance and resource efficiency, with various levels of potential achievement. There are tens of thousands of LEED-certified buildings in operation globally, most in major U.S. cities. The program is credited with igniting a green building industry around achieving its recognition, and its global foothold continues to expand. Other national and international programs and standards are in use and evolving, as well.
Benefits of green buildings
Green buildings help reduce negative impacts on the natural environment by using less water, energy, and other natural resources; employing renewable energy sources and eco-friendly materials; and reducing emissions and other waste. They can even provide net-positive impact in terms of generating their own energy or increasing biodiversity. Among the industry sectors that are major contributors to greenhouse gas emissions, the building sector has the largest potential difference to make in achieving significant reductions.
The implementation of green building measures that ultimately lead to these performance benefits also translates to economic benefits for multiple stakeholders. Developers benefit from higher property values due to optimized resource utilization and better-performing, longer-lasting buildings. Better buildings are more attractive to business owners and occupants for their environmental benefits, improved comfort, higher efficiency and less waste, and lower operating costs—which also positively impacts occupancy levels.
On top of that, the huge industry and job creation that exists around the development of green buildings continues to grow. And studies are showing that people who work in the improved environment of green buildings are realizing benefits in areas such as work performance and sleep quality.
As the green buildings industry evolves and matures with more support from formal policies, standards, and incentives, the challenge is to continue refining those mechanisms and the building practices and technologies they represent and guide. Since their introduction, green buildings have helped make notable progress in reducing building sector energy consumption and environmental impact.
However, there is opportunity for further improvement and added pressures to accommodate for global growth and balance the economics of green buildings. To keep pace and make additional forward progress, further innovation is needed in areas including but not limited to land use, energy and water conservation, materials, indoor air quality, and construction management.
Limitations of green buildings
The most prevalent limitation for green buildings is their cost. While green buildings can provide significant long-term financial benefits, their initial costs are higher than conventional buildings. The materials and technologies they utilize tend to cost more, the materials may be less readily available, and construction may take longer. Additionally, bank funding for green building projects can be more difficult to secure. Developers and financers must understand the cost savings over the building’s entire lifecycle and be willing and able to make a larger upfront investment.
Another challenge is that renewable energy sources, such as wind and solar, rely on varying weather conditions, which could make green buildings susceptible to fluctuations in energy supply. This also underscores that not all locations are equally suitable for green buildings; proper site selection is an important aspect in successful green building projects.
Related to fluctuations in renewable energy sources is a lack of full control over indoor conditions, such as building temperatures, when relying on natural resources to assist with heating and cooling. To solve for this may require certain building features, including its positioning on a lot to be handled in a non-preferred way or even in conflict with neighborhood zoning or other building guidance.
New and future developments in green buildings
Green buildings research is multi-faceted, with a lot of recent activity in the areas of construction and building technologies, energy and fuels, and civil engineering.
While the concept of green buildings originated in the commercial sector, emphasis is growing in the residential sector. Added building regulations, policies requiring energy efficiency, and increased public awareness and interest in this sector are creating higher demand for environmentally friendly and energy-conserving materials and other solutions for residential buildings.
An interesting development emerging in the green building materials space is the use of living materials. These are materials that consist of biological compounds whose growth serves a practical purpose. One example is self-mending concrete, which contains bacteria that grow within the pores to increase its strength or fill in cracks.
Green building materials in general continue to be an area of new development, as demand grows for products and technologies that help achieve LEED certification. Some of the demand is driven by increased government investment in motivating green buildings through encouragement of LEED and other certification programs, additional regulations and incentives, and support of research and development to introduce technology improvements and refine codes and standards.
Another important area of focus is on advanced building controls, which can be applied to new buildings or retrofitted in existing buildings to improve their energy efficiency, increase integration of clean energy sources, and coordinate electricity consumption within buildings and with the power grid. This involves integrating technology that automates operational functions, such as ventilation, heating, cooling, and lighting systems, according to schedules and other energy-saving adjustment parameters.
Green buildings research at PNNL
Researchers at PNNL focus in several areas that support green buildings, including but not limited to work to accelerate highly efficient solid-state lighting products to market, develop and deploy building controls, and advance improved appliance standards and building energy codes.
In advanced lighting, PNNL is helping meet U.S. Department of Energy (DOE) goals to reduce national lighting-related energy use by 75 percent by 2035. This includes contributing to technology improvements, such as new lighting measurement methods adopted by industry standards organizations and implemented by manufacturers to notably improve product performance.
Other PNNL solid-state lighting research seeks to deliver high-quality lighting precisely tailored to a particular setting and to explore new possibilities for leveraging the increasing connectivity of lighting products. These efforts are supported by a team of recognized experts, specialized facilities, and field work with partners that deploy new technology.
In the area of advanced building controls, researchers at PNNL have developed techniques that reveal all aspects of energy consumption and production in buildings. This comprehensive understanding leads to better approaches for controlling energy use, optimizing efficiencies, coordinating energy needs with the electric grid, and maximizing building operational performance and occupant comfort.
PNNL is uniquely positioned for this work, with expertise and facilities that support technology testing. One resource is a living laboratory—called the Integrated Building Assets—that includes a network of more than 20 PNNL buildings, a thermal energy storage system, battery energy storage, a laboratory, and electric vehicle chargers. PNNL-developed methods and technologies are deployed and adopted in projects and buildings across the United States, impacting millions of square feet. These advances help achieve enhanced building performance that leads to energy savings, economic benefits, and reduced carbon emissions.
PNNL also is assisting DOE in setting minimum energy conservation standards for appliances and equipment and developing test procedures to verify product compliance. PNNL’s expertise in economics, engineering, and energy markets is key to developing standards and understanding a variety of green building factors, including the cost-effectiveness of more efficient technologies and associated economic and environmental impacts.
PNNL is the lead support organization for DOE’s Building Energy Codes Program. As codes are formulated, PNNL contributes technical analysis and modeling capabilities and delivers cost-effective code change proposals to the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) and the International Energy Conservation Code (IECC). PNNL also assists in helping state and municipal governments adopt and implement new codes, develops and supports software tools used to demonstrate compliance, and provides education and training programs that help the workforce adapt to new technologies and practices.
Building energy codes vastly improve the efficiency of residential and commercial structures nationwide. Buildings constructed under the current code use about half the energy per square foot as a structure built in the late 1970s, when the Building Energy Codes Program began, and carbon dioxide emissions have been reduced by hundreds of millions of tons.
PNNL’s leadership in energy efficiency research is anchored by scientists and engineers known for their subject matter expertise and innovative solutions, representing disciplines ranging from electrical and mechanical engineering to economics and cybersecurity. Staff at PNNL lead key national projects, expand the body of knowledge through publications, and develop and deploy new technologies. Additionally, PNNL offers numerous facilities and equipment that help move concepts to real-world application.
Green buildings in action at PNNL
Over half of existing, non-leased buildings at PNNL are currently compliant with the revised Guiding Principles for Sustainable Buildings, far ahead of campus sustainability goals and progressing annually. PNNL continues to deliver on targeted commitments to optimize the energy performance of laboratory spaces and construct all new campus buildings according to the Guiding Principles, and intends to achieve net-zero emissions and energy-resilient campus operations by 2030 through an initiative known as NZERO.