From the Lab to the Marketplace (1995)

Tools for Building Designers

$208 Billion

Operating residential and commercial buildings in the U.S. costs consumers almost $210 billion each year. New technologies can reduce this cost, but they can be optimally deployed only with proper design tools. LBNL incorporates the knowledge gained over nearly two decades of building energy research into new computerized analytical and design tools, the most important of which is DOE-2. About 5% of commercial floorspace today is designed with DOE-2. Based on a recent survey of major users of the program, DOE-2 facilitates a savings of $85 million annually in energy bills—about $1.9 billion cumulatively for U.S. buildings constructed with the help of DOE-2 through 1993. California building standards (developed using DOE-2) save consumers almost $1 billion each year. Efforts to make existing tools more user friendly are projected to boost their application to 50% of all buildings.

Vladimir Bazjanac and Fred Winkelmann (seated) in front of a computer running DOE-2.

The nation's building industry is immense, but lacks the tools for optimizing energy efficiency. Thus, in the mid 1970s, LBNL accepted the challenge of developing a computer program for analyzing energy use in buildings. The resulting program—DOE-2—calculates hourly building energy use and cost from information about the building's construction; climate; operation; heating, ventilating, and air-conditioning systems; and utility rate schedule.

During 1975, the U.S. Energy Research and Development Administration (ERDA, which later became the Department of Energy), and the California Energy Commission (CEC) agreed that a comprehensive building energy analysis computer program was needed to develop and support energy efficiency standards. In response to this need, LBNL started a joint project with three national laboratories—LBNL, Los Alamos National Laboratory (LANL), and Argonne National Laboratory (ANL)—to develop the Cal-ERDA code, later to become DOE-1 and then DOE-2. LBNL led the effort, in charge of overall coordination and development of the basic user interface and simulation code. The objective was a whole-building energy analysis program that could simulate all building types in all climates, a program that was unbiased, well documented, and open to public scrutiny. ANL wrote the user documentation. LANL added active and passive solar simulation capabilities, and developed the engineering documentation. A private company, Consultants Computation Bureau, assisted in developing the interface (Building Description Language) and the programming. A steering committee with representatives from DOE, the California Energy Commission, and industry guided the development effort. To provide a program that would be technically sound and widely accepted, we based DOE-2 on algorithms developed by ASHRAE, a respected industry organization. We also used methods from earlier programs like NECAP, NASA's Energy Cost Analysis Program, and TWO-ZONE, a residential analysis program developed by LBNL.

The California Energy Commission estimates that the annual energy cost savings from the Title 24 standard, which was designed with DOE-2, was $420 million in 1985, $970 million in 1992, and will increase to $1.6 billion in 1999.

The cumulative California savings are estimated to be: $4.9 billion (1985-1992), and $13.8 billion (1985-1999).

The first version of DOE-2 was released in 1978. Fulfilling its original intent, it became the basis of four major standards: the California Title 24 building energy efficiency standard, considered the most advanced in the world; the national Building Energy Performance Standard, which was abandoned during the Reagan administration before it could be implemented; the DOE/ASHRAE 90.2 standards for residential buildings; and the DOE/ASHRAE 90.1 standards for commercial buildings, which are now voluntary and will become mandatory in each state, as required by EPACT.

In addition, DOE-2 is now widely used for the design of energy-efficient buildings and for impact analyses of new technologies. During the past ten years, DOE, the private sector, including utilities like Southern California Edison, Pacific Gas & Electric, and Bonneville Power Administration, and utility organizations such as the Electric Power Research Institute and the Gas Research Institute have supported improvements to DOE-2.

Through a schematic design tool that incorporates shadow-casting visualization, the Building Design Advisor (BDA) will assist building designers with initial building massing and orientation decisions, providing feedback on multiple performance considerations such as daylighting, solar gain, and shading from trees. The four charts compare key indicators for three design scenarios. DOE-2 will be the computational engine behind the BDA.

Today there are 1000 DOE-2 user organizations in the U.S. and 42 other countries. In the U.S., DOE-2 is used by 70% of the utilities promoting energy efficiency with demand-side management programs. Most commonly used in the design of new buildings, DOE-2 has also found a niche in the retrofit arena. Identifying energy retrofits for the Audubon Society's national headquarters was one prominent application.

A number of firms—ADM Associates (Sacramento, CA), Gable Dodd Associates (Berkeley, CA), ITEM Systems (Seattle, WA), Finite Technologies (Anchorage, AK), ERG International (Golden, CO), and Partnership for Resource Conservation (Boulder, CO)—have converted DOE-2 into a PC-based program or developed and marketed ancillary software.

Leveraged Energy and Economic Savings

Although not a hardware technology, DOE-2 directly facilitates energy savings in building projects where it is applied. Results of a 1991 survey showed that users help design or retrofit a total of 326 million square feet of buildings each year with DOE-2 (equivalent to about 5% of all commercial construction), at an average energy savings of 20%. The energy cost savings in these buildings is about $85 million/year. Buildings designed with the help of DOE-2 over the past decade have achieved about $1.9 billion in additional energy savings. For comparison, the total investment in development and support of DOE-2 to date is about $15 million. Based on a cost of $0.10 per square foot, the delivery of design and technical services using DOE-2 is now a $30-million annual industry.

The Future

PowerDOE—a new PC-based and user-friendly interface for DOE-2—is being developed by a joint private/public team with support from Electric Power Research Institute (EPRI), utility companies, the California Energy Commission, and the U.S. Department of Energy. A consortium of utilities and government agencies in Canada recently selected PowerDOE as the basis for its next-generation design tool. Current research efforts are focused on developing and commercializing PowerDOE (for new and retrofit applications), which will increase ten-fold the number of DOE-2 users.

Another goal is to expand DOE-2 use among architects (the program is currently used mostly by engineers) by coupling it to a Building Design Advisor (BDA) software package now under development at LBNL. Building designers will be able to use BDA to incorporate energy-efficiency considerations throughout the building design process, assisted by built-in, context-dependent advice on options to improve performance.

LBNL has proposed linking this energy design tool with an indoor environment model so that indoor air quality and energy efficiency can be evaluated early in the design process.