Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 91
The Role of Public Agencies in Fostering New Technology and Innovation in Building APPENDIX E NEW BUILDING TECHNOLOGY AND INNOVATION: A SELECTIVE REVIEW Few studies of the building-related industries include any consideration of changes in technology that have actually occurred over the past several decades. The committee undertook a brief and selective review of these changes to provide a basis for its assessment of the rate of innovation in these industries. The U.S. Office of Technology Assessment (1987) characterized technological innovation in the construction and materials industries in four categories: (1) development of new technologies within individual firms; (2) application or modification of new technology developed outside of the firm; (3) combining existing technologies in novel ways; and (4) incremental advances in existing techniques. It is generally difficult to distinguish innovation in the second two categories, although members of the committee suggested that these account for the preponderant share of all innovation in building, for both the construction process and the products thereof. COMPUTER-AIDED DESIGN AND CONSTRUCTION Much is made of advancements in computer-aided design and computer-aided manufacturing (CAD/CAM) in the automotive and electronics industries. Similar advancements are changing the ways that building designers and constructors do their jobs, and are increasing productivity in the process.
OCR for page 92
The Role of Public Agencies in Fostering New Technology and Innovation in Building Early progress in the field was spurred by the development, in the 1960s, of the COGO system (named for its ability to handle coordinate geometry) that helped highway engineers locate new routes and structural engineers analyze building frames. The innovation of an effective and—for the time—user-friendly program that solved problems common to almost all parts of the diverse engineering profession spurred development of tools for soil and rock mechanics, steel and concrete structures, highway construction planning, and an array of other applications. These tools required large computers and programming sophistication that limited their value to those professionals and firms who were sufficiently large or specialized to justify the investment needed to gain access to a system. The general-purpose CAD systems that began to appear in the 1970s, offering more effective data management and faster updating of the huge number of drawings required for the construction of a large facility, had the same problem. The appearance of powerful desktop computers—the PC (personal computer) and distributed workstations—signaled a change. Programmers made great strides in developing easier-to-use software, and the total investment required to begin using CAD came down to levels that virtually any engineer, architect, or planner could afford. However, the machines still were tied to the office desktop. Applications in construction were limited primarily to project scheduling and accounting, and to designers' revisions of preconstruction drawings into ''as-builts." Now, in the 1990s, the situation is changing quickly. Constructors are finding that CAD systems allow them to ask 'what if' with respect to how hoists, cranes, and other large equipment will fit and infract on the job site. The systems help coordinate trades. They facilitate calculation and control of materials quantities. Powerful portable computers—the new generation of "laptops"—are durable enough for use in the field. With data connections to the central office, site superintendents and field engineers can have full access to all available information about a project. The new technology, while boosting productivity, is creating what ENR,39 chronicle of the construction industry's day-to-day activities, termed "cultural chaos." Traditional ways of conducting business among owners, designers, and constructors are changing as constructors acquire design capability, and designers, having already input data for their own purposes, find it easy to make quantity estimates and do other tasks normally left to the constructor. Both groups, as well as owners who could find such data useful in subsequent management of their facilities, are unused to sharing and cooperation. Issues of potential liability and copyright ownership are arising. Those involved in 39 Formerly Engineering News Record.
OCR for page 93
The Role of Public Agencies in Fostering New Technology and Innovation in Building design-construction development, because they create the design files and then use them in-house for construction, avoid some pitfalls and are leading in this broadening application of computers in aid to design and construction. ENERGY MANAGEMENT IN BUILDINGS Space heating, cooling, lighting, and other activities make the building sector one of the primary consumers of energy in the U.S. economy. The oil crises of the 1970s and continuing increases in energy process, concerns about global warming and other large-scale environmental effects of energy use, and building owners' ongoing efforts to control operating costs have motivated substantial effort to develop new technologies for the control, conservation, and reduction of energy use. One study of both gas and electric household appliances shows that the 1985 average efficiency of new appliances purchased, as well as the efficiency of the most efficient new appliances available, are consistently better than the estimated average efficiencies of appliances in service (see Figure E-1); (Geller et al., 1987). In many cases, the best available unit is 30 to 40 percent more efficient than the average unit purchased, and current research and development activities promise to reduce unit energy use as much as 40 to 50 percent more during the 1990s. Space heating and ventilation are major energy consumers in buildings, as well as important factors in determining how well a building is judged to perform. Innovations in these areas thus have both monetary and non-monetary payoffs. The committee conducted an informal survey of federal government mechanical engineers and produced a list of 16 specific innovations that have entered practice in the past 25 years (see Table E-1). The committee made a similar survey of government electrical engineers (see Table E-2). Two items on the lists are identical (item 3: variable frequency drives, and item 6: energy-monitoring and control systems). STRUCTURES AND THEIR CONSTRUCTION While the committee decided to exclude the housing sector from much of its discussion, members noted that the refinement of dimensional lumber in the late nineteenth century, by Bemis and his successors, was a major innovation in home building. Arguments have been advanced to suggest that uniquely American 2 x 4 stud and balloon-or platform-frame building systems are highly flex-
OCR for page 94
The Role of Public Agencies in Fostering New Technology and Innovation in Building Figure E-1 Unit energy consumption (UEC) of household appliances in the United States, source: Geller, et al., (1987).
OCR for page 95
The Role of Public Agencies in Fostering New Technology and Innovation in Building Table E-1 Major HVAC Innovations Accepted in the Past 25 Years. Development Year Accepted (average of estimates) Year Accepted (Range of estimates) 1. Screw compressors (replacing some centrifugal and reciprocating compressors) 1969–1970 1965–1980 2. Variable air volume systems (replaced constant-volume systems) 1972–1973 1970–1975 3. Energy monitoring and control systems (central) (new development) 1973–1974 1970–1977 4. Electronic controls (replaced some pneumatic controls) 1974–1975 1965–1980 5. Computer-aided design (loads) (replaced hand calculations) 1969–1970 1965–1972 6. Energy use simulation (replaced degree-day calculations) 1974–1975 1968–1979 7. Variable-frequency speed controls (replaced some other methods of controlling fluid flows) 1983–1984 1978–1987 8. Thermal storage systems (new development) 1980–1981 1966–1988 9. Solar energy systems (new development) 1976–1977 1971–1982 10. Total/selective, energy systems (new development) 1980–1981 1976–1986 11. Heat pumps (residential) (new development) 1970–1971 1955–1981 12. Two-stage absorption air-conditioning units (replaced single-stage units) 1977 1965–1982 13. High-efficiency furnaces (residential; replaced low efficiency units) 1983–1984 1980–1986 14. High-efficiency air conditioning units (residential; replaced low-efficiency units) 1982–1983 1980–1986 15. Scroll compressors (replaced some reciprocating compressors) 1985–1986 1984–1988 16. Alternate chlorofluorocarbon refrigerants (replacing some other refrigerants) 1990 1990 Note: Identified at the March 27, 1991 meeting of the Federal Construction Council Consulting Committee on Mechanical Engineering; the committee used a simplified ''Delphi" procedure.
OCR for page 96
The Role of Public Agencies in Fostering New Technology and Innovation in Building Table E-2 Facilities-Related Electrical Engineering Developments Accepted in the Past 25 Years. Development Year Accepted (average of estimates) Year Accepted (range of estimates) 1. Solid-state circuit breakers (replacing other circuit breakers and fuses) 1981 1975–1986 2. Static uninterrupted power supplies (replacing engine-generator sets) 1979–1980 1970–1988 3. Variable-frequency drives (replacing other methods of speed control) 1980–1981 1970–1988 4. Programmable lighting controls (new technology) 1984–1985 1980–1987 5. Solid-state lighting ballast (replacing inductive ballast) 1985 1980–1987 6. Energy-monitoring and control systems (new technology) 1984–1985 1978–1989 7. Fiber optics (replacing copper conductors) 1983–1984 1980–1986 8. Multiplex fire alarm systems (replacing separately wired systems) 1983–1984 1980–1986 9. New aluminum alloys for conductors (replacing older alloys) 1982 1975–1988 10. High-technology telephone and data transmission systems (replacing older systems) 1985–1986 1982–1989 11. Amorphous-metal transformer cores (replacing laminated cores) 1989 1988–1990a 12. Solid-state lighting dimmers (replacing rheostats) 1983–1984 1972–1987 13. True root-mean-square meters (replacing sine-wave-only meters) 1987–1988 1985–1989 a One participant felt that this technology has not yet been accepted; he did not project a year of acceptance. Note: Identified at the April 3, 1991 meeting of the Federal Construction Council Consulting Committee on Electrical Engineering; the committee used a simplified "Delphi" procedure.
OCR for page 97
The Role of Public Agencies in Fostering New Technology and Innovation in Building ible, inherently economical, and even "democratic," because virtually anyone can use them with a minimum of special knowledge or skill. 40 A recent study of the home-building industry identified more than 100 specific innovations in housing construction that have supplemented this basic system since 1945 (see Table E-3); (Slaughter 1991). Table E-3 Sample of Innovations in Permanent Residential Structures, 1945 to 1990. Source: Slaughter, (1991). Functional Area No. of Innovations Structural exterior wall framing 7 Enclosure and insulation 8 Openings 13 Interior wall framing 7 Foundation 12 Floor framing 10 Roof framing 7 Roof covering 7 Plumbing 12 Electrical wiring 4 Heating/ventilation/air conditioning 12 Interior finish 18 TOTAL 117 In the areas of nonresidential building, the past several decades have witnessed the introduction of a variety of new structural materials and techniques for enclosing space and resisting loads, and for constructing these structures. Table E-4 lists major examples. The development of fabric tension structures can be traced to the pioneering work of Frei Otto in the 1960s, but building applications did not achieve widespread or notable commercial use until nearly two decades later with the advent of Teflon-coated fabrics, which promised longer life and better performance (Otto, 1969). 40 This viewpoint is advanced notably in a 1978 essay by architect Andrew Rabeneck, then a principal in the San Francisco offices of The Ehrenkrantz Group.
OCR for page 98
The Role of Public Agencies in Fostering New Technology and Innovation in Building Table E-4 Innovations in commercial structures Tensile fabric structures Sliding Teflon bearings Seismic base isolation Slurry-wall construction Up-down construction Fall protection on building construction Composite steel-concrete floor construction Metal floor and roof decks Electrified floor construction Single-wythe brick masonry cladding (Sarabond) Lateral framing systems for high-rise buildings Precast concrete construction Tilt-up construction Pumped concrete High-and superhigh-strength concrete Concrete admixtures Concrete floor/deck hardeners Epoxy-coated concrete reinforcing Cathodic protection of rebars Prestressed concrete Lift-slab building construction Staggered truss system Pre-engineered structural systems Tuned-mass damper for high-rise buildings (drift) Active drift control systems for high-rise buildings Blast-resistant (window) construction Anti-terrorist design and construction Single-ply membrane roofing Curtain wall construction Critical path method of scheduling Ultimate strength design of concrete Plastic design in steel Limit state design in timber Sprayed-on fire proofing Weathering steel Fire retardant ply-wood Welded-flame system scaffolding Motorized self-climbing scaffolding Flying formwork Gang-forms Computer-aided design Computer-aided drafting These new fabric materials provided lightweight and relatively inexpensive cover for such large, open spaces as sports stadiums and performing arts arenas. Their development resulted from close collaboration among architects, structural engineers, and product manufacturers. The design of several very attractive
OCR for page 99
The Role of Public Agencies in Fostering New Technology and Innovation in Building buildings (notably the Hajj terminal in Jedda, Saudi Arabia), involving cooperation among a broad cross section of design, engineering, and product development specialists, demonstrated the new potential for coated-fabric structures. Lightweight steel stud framing systems emerged from a combination of factors, including the desire to find a fire-resistant substitute for wood-based framing products, mainly for light commercial applications; a concerted effort on the part of U.S. steelmakers to move from automotive applications into the building industry; a general degradation in the quality and availability of dimensioned framing lumber; and participation of the U.S. gypsum industry in the development of design, engineering, and construction methods. Design professionals, including architects, interior designers, and engineers, worked with building code officials, steel fabricators, and architectural specialty manufacturers to develop standard solutions and approaches, which continue to be developed for both residential and commercial applications. The steel framing industry has developed a series of structural (rather than veneer, partition, or furring) applications for lightweight steel, including approaches that can be applied to low-rise multistory buildings. The brick and concrete masonry industries, which traditionally captured a larger proportion of labor and materials in such markets, have resisted these innovations.41 INTERIORS Raised-floor wire management systems emerged as a direct response to the explosion in wire-based computing and communications technologies in offices and the need to provide a convenient, safe, and flexible means for handling wires. Initial raised-floor product designs, produced mainly to provide electrical continuity and adequate underfloor wire management space, failed to perform adequately from the standpoint of appearance, cost, and acoustical quality. When architects, interior designers, and electrical engineers were retained by several key manufacturers in subsequent product design efforts, a second generation of more satisfactory raised-floor systems emerged. European product manufacturers have developed thinner raised-floor systems that do not employ structural frameworks to support removable floor tiles. 41 When the brick industry developed guidelines for the use of brick veneer with steel stud backup, the engineering design provisions of these guidelines were characterized by some members of the steel framing industry as excessively conservative and intended to make steel framing approximately equal in cost to masonry.
OCR for page 100
The Role of Public Agencies in Fostering New Technology and Innovation in Building Personal environment control furniture systems resulted from the proliferation of electronic office equipment, but they were also a response to difficulty experienced with conventional building mechanical systems in providing for human comfort in office environments. Architects, mechanical and electrical engineers, interior designers, and furniture manufacturers collaborated to develop a new concept for servicing individual workstations, based on the principle of placing controls and output devices where they are needed, rather than in remote locations. In contrast to experience with raised-floor wire management systems, the early involvement of a broad range of design disciplines and extensive concept testing with potential users appears to have avoided unsuccessful initial results. REFERENCES Geller, H., J. P. Harris, M. D. Levine, and A. H. Rosenfeld. 1987. The role of federal research and development in advancing energy efficiency: A $50 billion contribution to the U.S. economy. Annual Review of Energy 12:357–397 Office of Technology Assessment. 1987. International Competition in Services: Banking Building Software Know-How . Washington, D.C.: U.S. Government Printing Office. Otto, F., 1969. Tensile Structures: Cables, Nets and Membranes. Cambridge, Mass.: MIT Press. Slaughter, S. E. 1991. "Rapid" innovation and the integration of components: A comparison of user and manufacturer innovations through a study of the residential construction industry. Ph.D. thesis submitted in the field of Management of Technology, Massachusetts Institute of Technology, Cambridge, Mass.
Representative terms from entire chapter: