Journal of Architectural Engineering

Within the residential sector, the low-income segment accounts for a significant amount of energy consumption. In addition to poor housing conditions in the low-income sector, occupant behavior is one of the most important drivers of energy performance. This paper examines specific cases of behavior in low-income housing in hot-humid climates. Given the scant literature available on this subject, this study uses both quantitative and qualitative approaches to concurrently analyze both (1) subjective perceptions of low-income occupants and (2) real field data. Using principal component analysis, a wide range of behaviors was categorized into nine independent factors. Then, using multiple regression analysis, those factors were ranked in terms of their impact on household energy bills. The results revealed that the top five behavioral factors that have a significant impact on the energy bills of low-income occupants are the following (in order of importance): (1) cooling set point during summer; (2) energy-saving practices/behaviors of households; (3) occupant behavior with respect to indoor environment quality; (4) occupant behavior with respect to lighting and electrical appliances; and (5) heating set point during winter. The findings from this research will contribute to a better understanding of the impact occupant behavior in the low-income housing sector has on energy consumption.

The authors present the results of a feasibility study to apply the major steps of the methodology to quantify seismic performance factors (SPFs) for structural insulated panels (SIPs) as the seismic force–resisting system for residential and light commercial buildings. This methodology uses collapse evaluation to determine acceptable SPFs. Structural response prediction was assessed through the combination of building code seismic provisions, nonlinear dynamic analyses, and risk-based assessment techniques. The SIP system in this study consisted of a rigid foam insulation core sandwiched between two sheets of oriented strand board. Analytical modeling was carried out using seismic analysis software. The results of the preliminary study show that the methodology and the seismic analysis software used in this study can lead to the determination of SPFs for SIP systems, but extensive experimental test results among other data are needed for a comprehensive project to quantify SPFs.

The last decade has witnessed a heightened interest in making buildings more sustainable, which has been fueled largely by the increase in energy costs and advancements in manufacturing technology. Lighting consumes a substantial amount of this energy, making it necessary to look for alternative technology that depends more on natural lighting. This study investigated a novel building envelope material that consists of optical fibers embedded in concrete. The fibers are used to channel solar radiation into the building to reduce the dependence on artificial lighting especially during peak time. This paper presents a geometrical ray-tracing algorithm to simulate light transmission properties of the proposed translucent concrete panel. It was concluded that a tilt angle of 30° for the panel transmits the maximum amount of light among all the tilt angles considered. Using this tilt angle, the rate at which sunlight radiation is absorbed by the panel was calculated, and a preliminary study was conducted to estimate the solar heat gain coefficient of the panel for possible use in place of a glazing material by the construction industry.

In the San Francisco Bay Area and throughout much of California, there are a large number of wood-frame buildings with garage space at ground level, resulting in open fronts on one or two sides. This type of geometry results in a soft and weak first story, and buildings of this archetype are generally referred to as soft-story buildings. During an earthquake, these buildings are susceptible to severe damage and collapse and have been recognized as a disaster-preparedness problem. The five-university Network for Earthquake Engineering Simulation (NEES)-Soft project culminated in a series of full-scale soft-story wood-frame building tests to validate two different retrofit philosophies and included a 2-month test program encompassing four different retrofits. The building had $370\hspace{0.17em}{\text{m}}^2$ of living space and was designed to be generally representative of older San Francisco Marina and Mission District construction, circa 1950s. Following the retrofit testing, which only moderately damaged the test building, retrofits were removed, repairs were conducted, and the building was nominally instrumented for testing without retrofits in place. A series of unidirectional shake table tests was conducted, beginning with the Cape Mendocino acceleration record scaled to 0.4g spectral acceleration up to two successive shakes with the Superstition Hills acceleration record scaled to 1.8g spectral acceleration. Little residual lateral displacement was observed until the last two earthquakes. The objectives of the collapse testing phase of the NEES-Soft project were to (1) observe and document the nature of the soft-story collapse mechanism and (2) quantify the collapse drift for these types of soft-story wood-frame buildings. The building collapsed at approximately 19% interstory drift of the soft story (ground floor).

Although current structural design philosophy privileges the notion of structural regularity, contemporary architecture includes building irregularities. Often, conventional structural design is forced on nonconventional structures in this type of building, forcing a round peg in a square hole. This incongruence calls for a thorough study of irregular buildings. The present article uses a plan and vertically irregular building to compare a conventional and a nonconventional structural system, allowing for an analysis of the effect of structural configuration on seismic response and direct building costs. In this study, the NSR-10 building code is applied (Colombian Code of Seismic Design). Nonlinear static pushover analyses and nonlinear time-history analyses are performed to determine and ultimately compare each system’s real capacity. Furthermore, a comparative analysis of direct building costs (in unitary terms) is done for both structural systems. The substantial impact of structural system type on both cost and seismic behavior is demonstrated, providing sufficient evidence to question the paradigm of conventional systems as both more cost effective and more seismically sound.