High Performance Buildings
Americans spend most of their time inside buildings. We take for granted the shelter, protection, warmth, coolness, air and light that buildings provide, and rarely give a thought to the systems that deliver these services unless there’s a power interruption or other problem. In addition, few Americans understand the environmental consequences of maintaining indoor comfort levels.
Today’s buildings typically use mechanical equipment powered by electricity or fossil fuels for lighting, heating, cooling and maintaining air quality. Last year, buildings in the U.S. consumed more energy and contributed 36 percent of the carbon dioxide (CO2) emissions released into the atmosphere. Fossil fuels burned to generate electricity and condition buildings emit other pollutants that cost citizens and insurance companies millions of dollars in health care costs each year. Mining and extraction of fossil fuels also have environmental impacts, and instability in pricing causes concern among both business people and homeowners. Creating buildings that use less energy not only reduces and stabilizes costs, but also reduces environmental impact.
The good news is that we have the knowledge and technologies to reduce energy use in our homes and workplaces without compromising comfort and aesthetics. The bad news is that we are not taking full advantage of these advances—buildings are typically designed and operated without considering all the environmental impacts.
For decades, researchers and innovative designers and builders have created buildings that use the environment as a resource rather than an obstacle to be overcome. Over the years, building professionals have steadily refined the equipment and design strategies used in these environmentally responsive buildings. This evolutionary process and the resulting body of knowledge has led to the concept of “whole-building” design.
In the whole-building approach, designers create a computer model of a structure during the early stages of the design process. Using this model, together with improved communication among
the various players in the design/build process, designers can integrate disparate building elements into the most energy-efficient, cost-effective and comfortable building possible. The goal is to minimize the building’s impact on the environment, and quite often the results are remarkable—dramatic savings in energy use without a substantial increase in design and construction costs. As a bonus, these buildings can improve the health, comfort and productivity of occupants in measurable ways. In commercial buildings, dollar savings from increases in productivity
and reduced absenteeism can dwarf savings from reduced energy use.
In 1998, the U.S. Department of Energy (DOE) began working with the commercial buildings industry to develop a 20-year plan for research and development on energy-efficient commercial buildings. More than 250 people from 150 building organizations worked together to create a technology roadmap report recommending strategies for making commercial buildings more energy efficient. The overall goal of DOE’s High-Performance Buildings Program is better buildings that save energy and provide a quality, comfortable environment for workers. The program is targeted toward the building community, especially building owners, engineers and architects. Encourage building professionals to submit new commercial buildings to be a part of the High-Performance Building program. To participate, you must start very early in the design phase—before any other work is done—and must anticipate a 70% or more energy cost reduction.
A high-performance commercial building is a building with energy, economic, and environmental performance that is substantially better than standard practice. It's energy efficient, so it saves money and natural resources. It's a healthy place to live and work for its occupants and has relatively low impact on the environment. All this is achieved through a process called whole-building design.
Whole-building commercial design considers all building components during the design phase. It integrates all the subsystems and parts of the building to work together. Because all the pieces must fit together, it is essential that the design team be fully integrated from the beginning of the process. The building design team can include architects, engineers, building occupants and owners, and specialists in areas such as indoor air quality, materials, and energy use.
Whole-building design takes into consideration the building structure and systems as a whole and examines how these systems work best together to save energy and reduce environmental impact. For example, a building that uses extensive daylighting techniques will reduce the amount of heat given off by lighting fixtures, thus allowing for a smaller air conditioning system. This whole-building philosophy considers site, energy, materials, indoor air quality, acoustics, natural resources, and their interrelation.
This approach brings together building design, energy efficiency, and today's solar technologies to boost your energy savings and make the most of all your building's elements. It reduces the amount of energy required to operate a building compared to conventional buildings. It improves the comfort of building occupants by using pleasing architectural designs to brighten up work areas using sunlight rather than electricity, without causing excess glare.
What are the benefits of whole-building design?
Commercial buildings consume 17% of the total energy consumed in the United States. By creating buildings that use less energy and have lower power demands, greater robustness of the buildings as well as the power grid is achieved. This reduces the need for fossil fuels and consequential environmental impact.
Benefits of whole-building design include:
How much does it cost?
There is a growing interest today on the part of commercial building owners, facilities managers, architects, engineers, and builders to design and construct the best possible building for the allotted budget. Depending on the aggressiveness of the design, experience has shown that it costs no more than 10% more to build high-performance buildings. Some high-performance buildings cost less to construct. Sometimes additional costs can be procured using cost-benefits ratios and life-cycle costing. The added cost, if any, of system investment each year is compared to the cost of fuel saved each year. Total energy costs are, on average, about 50% less than those for conventionally designed buildings. In many cases, the right-sizing of mechanical systems through passive solar design offsets the costs for additional windows or controls.
Design Approach: Frequently Asked Questions
1. Will the building look unusual?
Many owners want to make a statement with whole-building design and sustainable features. Many other owners, however, are creating these buildings at little or no additional cost that appear no different from conventional designs.
2. Is "whole-building" the same as energy efficiency?
Energy efficiency does figure prominently in our designs, but there are many other aspects to design. The whole-building concepts looks to integrating all disciplines to meet a set of goals for a building.
3. Are these buildings just for large corporations?
Many of the early adopters were municipalities and government agencies that recognized the opportunities for life cycle cost savings. Anyone can benefit from whole-building design.
4. Is there a market demand for whole-building design?
Yes. Corporations, universities, and government agencies are demonstrating that whole-building design can provide better working environments and cost less to operate. Students, employees, and non-profit community groups are all demanding and campaigning for the adoption of low-energy buildings.
5. If I decide to "go green," won't I have to come up with more money?
Not necessarily. Some prescriptive requirements, such as use of Photovoltaics, may drive higher project costs, but several owners have published data demonstrating their success in procuring green buildings for less than the cost of a conventional building. Look around for incentives. These include incentives from local utility companies tied to energy efficiency, grants for renewable energy installations, and various tax rebate programs.
6. Isn't whole-building design based on fringe technologies?
Most projects have achieved good performance using conventional building systems. In many instances, it is the effective integration of conventional systems, rather than the use of a new technology, that conserves resources and improves environmental quality. New technologies are only used after careful consultation with owners and the design team.
7. If it hasn't been done before, isn't it hard to do?
Whole-building projects are demonstrating that it's not hard. For example, the fact that very few commercial buildings employ natural ventilation does not mean that it cannot effectively deliver satisfactory comfort year-round in many climates. In many circumstances, the techniques were used extensively before wide-spread use of air-conditioning.
8. How can you get high-quality materials and systems and good environmental performance at the same time?
Removing highly toxic chemicals from a product or designing a fixture to use less water does NOT mean that the product will be less effective or have a shorter life.
A high performance commercial building design strategy requires a clear definition of goals and performance benchmarks from the owner and an inter-disciplinary design and construction approach. Design criteria should be based on environmental and energy cost/benefit analyses and attention to "whole-building" and system performance
Because all commercial building components must work together successfully long after project completion, it is essential that sufficient time be set aside in the beginning of a project for design team development, goal setting, and project planning. A sustainable building can only be accomplished when everyone (the building owner, future occupants, design team) have the same energy and environmental goals for the project from the start. In short, everyone that is affected by this building in a decision making position should be involved at the project's beginning. Ultimately, the building owner is responsible for setting the goals and their implementation. It is the design team's responsibility to translate goals and budget for the project into measurable benchmarks for design, construction, and operations so the project will be successful.
Traditionally, commercial building design choices are based on budget or time considerations. Single building components are added or deleted to meet time or budget constraints without evaluating their impact on total building performance. Yet basic design goals such as minimizing energy consumption or maximizing daylight cannot be done without understanding the impact of interrelations between parts of the building including window glazing systems, thermal envelope, mechanical system integration, orientation, and floor plate proportions. High performance building design must ensure complete integration to achieve optimal building performance. These interrelations are very complex. As a result, computerized simulation studies are necessary to properly account for interrelationships. Water and resource conservation along with recycled, reusable, and nontoxic sustainable materials should also be considered in the design stage.
Building construction is an act of creation than begins long before the first shovel is placed in the ground. It begins with a statement of design intent, followed by creation of a performance program. Once these are approved, the process concludes with drawings and specifications then finally building commissioning during occupancy. Although simplified, below are some general guidelines:
Statement of intent — A good statement of intent will clearly set forth the goals of the project, current and possible future uses for the building, as well as include a description of how building systems are to perform. Clearly defined goals and objectives here will help in the bidding process later on.
Performance program — The performance program is the strategy for implementing the goals established by the statement of intent, such as budget, space planning, integrated building systems, and other specific needs. It will also set performance goals for systems such as lighting wattage per square foot and include such amendments as elimination of toxic materials. Several building rating systems exist that can be used to write the performance programs, such as the U.S. Green Building Council's Leadership in Energy and Environmental Design or LEED rating system.
Drawings and specifications — These record the design intent. Most design firms use the format created by the Construction Specifiers Institute (CSI). However, keep in mind that for high-performance buildings, you will need to add "integrated systems drawings" and supporting documents that will illustrate how different building components relate to and impact each other. Specifications that accompany the drawings must clearly explain the design intent, especially if a project includes unusual or innovative practices or requirements.
Building commissioning — This is the process of ensuring that building systems such as air-handling equipment, security systems, and elevators are designed, installed, functionally tested and capable of being operated and maintained according to the owner's operational needs. Commissioning begins in the design stage and extends at least one year into the initial occupancy of the building. This process ensures that the building is operating as designed. It also saves building owners money by keeping equipment and building systems compliant with warrantees, prevents future excessive repairs, reconfiguration and replacement costs, employee absenteeism due to uncomfortable work environments with poor air quality, and frequent tenant turnover.
This article was provided by the Citizens Information Center in cooperation with the
National Association of Certified Home Inspectors.
Providing home inspections in Knoxville, Oak Ridge,
Maryville and much of east Tennessee