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
than one-third of the nation’s
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.
Whole-Building Design
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.
The DOE High-Performance Buildings Program
Design Approach
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.
Design Guidelines
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:
- Reduce energy use by 50% or more
- Reduced maintenance and capital costs
- Reduced environmental impact
- Increased occupant comfort and health
- Increased employee productivity
Employee productivity and business
profitability are linked. Recent studies have shown an increase in
employee productivity when buildings are designed with occupants in
mind—natural light, comfortable temperatures, and a quiet work
environment being the most important issues. Research suggests that a
well-designed workplace can increase employee productivity by 20%.
Further, studies also show that a pleasant indoor building environment
helps attract desirable tenants for building owners, increasing the
number of potential renters for a building.
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.
Design Guidelines
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
Predesign
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.
Design
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.
Construction
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.