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Research Theme: Design & Building

Built environment scholarship at the scales of the interior space to the building

Time-Cost Performance Effect of Change Orders from Accelerated Contract Provisions

Choi, Kunhee; Lee, Hyun Woo; Bae, Junseo; Bilbo, David. (2016). Time-Cost Performance Effect of Change Orders from Accelerated Contract Provisions. Journal Of Construction Engineering And Management, 142(3).

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Abstract

Accelerated contract provisions (ACPs) such as cost-plus-time (A+B) and incentives/disincentives (I/D) are increasingly common, yet very little is known about their pure time-cost performance effects on change orders. To fill this large knowledge gap, a two-stage research methodology drawing on 1,372 highway improvement projects completed in California was adopted for this study. The Stage I study investigated the marginal change-order impacts of two ACPs, pure A+B and I/D combined with A+B. How ACP change orders affect projects' time-cost performance was numerically modeled and successfully validated over the Stage II study. The results clearly showed that both ACPs led to more schedule-change and cost-change orders than conventionally contracted projects, whereas I/D combined with A+B performed significantly better than pure A+B in terms of the magnitude of schedule-change orders. This conveys an important recommendation to state transportation agencies (STAs) that A+B be used with an I/D provision. The results and numerical models of this study would help STAs better assess and justify the impact of change orders on the duration and cost of projects, enabling them to more effectively use contingency amounts. Use of the models can also benefit contractors requesting a change order because the models can provide them with advanced knowledge of the probable time-cost growth rates specifically for the pursued ACP. (C) 2015 American Society of Civil Engineers.

Keywords

Construction Industry; Contracts; Costing; Incentive Schemes; Numerical Analysis; Order Processing; Performance Evaluation; Roads; Scheduling; Time Management; Transportation; Projects Time-cost Performance Effect; Cost-change Order; Accelerated Contract Provision; Knowledge Gap; California; Acp; Schedule-change Order; State Transportation Agency; Numerical Model; Sta; Incentive; Highway Improvement Project; Labor Productivity; Construction; Impact; Model; Projects; Change Order; Highway Rehabilitation; Decision Modeling; Regression; Validation; Contracting

The Urban University’s Hybrid Campus

Way, Thaisa. (2016). The Urban University’s Hybrid Campus. Journal Of Landscape Architecture, 11(1), 42 – 55.

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Abstract

With the growth of urban campuses in the twenty-first century, how can landscape architecture foster the innovation associated with cities and urban neighbourhoods? In Seattle, West Campus at the University of Washington serves as a good urban neighbour while engaging the traditional experiences of a campus. Additionally, the design suggests how an urban campus might generate the culture of an urban innovation district. The contribution of landscapes to innovation districts has rarely been considered in campus design because the focus has been on the architecture of the buildings and the culture of collaboration as social phenomena. This paper explores how the public landscapes of parks, courtyards, and streets shape the experience of an innovation district and contribute to fostering creativity and serendipity. As an extension, the paper suggests the importance of universities in the creation and stewardship of vibrant, creative, and resilient cities.

Keywords

City Planning; Innovation District; Student Residential Planning; University Landscape Design; Urban Campus

In Situ Measurement of Wind Pressure Loadings on Pedestal Style Rooftop Photovoltaic Panels

Bender, W.; Waytuck, D.; Wang, S.; Reed, D. A. (2018). In Situ Measurement of Wind Pressure Loadings on Pedestal Style Rooftop Photovoltaic Panels. Engineering Structures, 163, 281 – 293.

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Abstract

The installation of rooftop photovoltaic (PV) arrays is increasing throughout the US. Until recently, pedestal type PV framing systems for rooftops were basically designed using procedures from the ASCE7-10 Components and Cladding Standard for rooftop equipment. The 2011 Japanese Standard Load design guide on structures for photovoltaic arrays was useful in characterizing the pressure coefficients on rooftops, but the Standard employs different wind speed and importance factors, making its use in the US quite limited, Even the updated 2017 version is written for a different audience. Because rooftop pressure loadings are high due to flow separation, SEAOC and other organizations contracted boundary layer wind tunnel tests of panels attached to rooftops to ascertain if the ASCE7-10 equipment loadings were appropriate. The investigations resulted in new standards for pedestal-style arrays that appear in Chapter 29 of ASCE7-16. However, the new standards are limited to simple geometries and orientations, and the dynamics of the simply-supported thin PV plates do not appear to be considered. Questions regarding the ability of the boundary tunnels to simulate accurately the turbulence at the scale required for the attached panels have been raised. In response, very limited full-scale investigations in large-scale tunnels and in situ have been undertaken to calibrate the tunnel results. The results of this paper represent one of these calibration investigations. Specifically, in situ full-scale net wind pressure loadings on a rooftop PV array in a pedestal-style framing system located on the three story Hogue Technology Building of Central Washington University (CWU) in Ellensburg, Washington were measured. The CWU campus has a rural setting in a region with steady winds: Ellensburg is located in the Kittitas Breezeway portion of the Northwest wind power region. Indeed, the Wild Horse Wind and Solar Farm is located on the outskirts of town. The data described here were collected from April through August 2014. The measured net pressure coefficient time series were similar to those for rooftop pressure loadings for low-rise buildings described in the literature such as the Wind Engineering Research Field Laboratory at Texas Tech University (Ham and Bienkiewicz, 1998 [1]; Levitan and Mehta, 1992 [2]). The analysis of the net pressure time series data included an examination of the minimum, maximum, mean, and RMS values. Preliminary results suggest that the range of the values is larger than assumed in the ASCE7 Standard, and that the magnitude of the loadings vary considerably spatially over the multiple panel array. The pressure loading measurements are ongoing.

Keywords

Building Integrated Photovoltaics; Buildings (structures); Calibration; Design Engineering; Pressure Measurement; Roofs; Solar Cell Arrays; Standards; Time Series; Turbulence; Wind Tunnels; Japanese Standard Load Design Guide; Wind Pressure Loading Measurements; Asce7-10 Components-cladding Standard; Tunnel Calibration; Texas Tech University; Kittitas Breezeway Portion; Wild Horse Wind And Solar Farm; Ellensburg; Central Washington University; Hogue Technology Building; Boundary Layer Wind Tunnel Test; Flow Separation; Multiple Panel Array; Wind Engineering Research Field Laboratory; Net Pressure Coefficient Time Series; Northwest Wind Power Region; Pedestal-style Framing System; Pv Plates; Rooftop Equipment; Pedestal Style Rooftop Photovoltaic Panels; Solar-arrays; Loads; Simulation; Wind Engineering; Photovoltaic Modules; Solar Energy; Full-scale Measurements; Wind Loadings; Photovoltaic Cells; Roofing; Wind Power; Structural Engineering; Boundary Layers; Cladding; Wind Tunnel Testing; Solar Cells; In Situ Measurement; Framing; Photovoltaics; Engineering Research; Wind Measurement; Pressure; Panels; Wind Pressure; Design Standards; Fluid Dynamics; Low Rise Buildings; Colleges & Universities; Wind Speed; United States--us

Normative and Descriptive Models for COBie Implementation: Discrepancies and Limitations

Abdirad, Hamid; Dossick, Carrie S. (2019). Normative and Descriptive Models for COBie Implementation: Discrepancies and Limitations. Engineering, Construction And Architectural Management, 26(8), 1820 – 1836.

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Abstract

Purpose The purpose of this paper is to inquire into the reasons why Construction Operation Building Information Exchange (COBie) has not become mainstream across the construction industry despite the significant attempts to promote it. Design/methodology/approach This paper framed and compared the normative model of COBie to a descriptive model of COBie. The normative model was based on the assumptions and planned procedures outlined in the COBie documentation. The descriptive model was developed through a case study of COBie implementation, with ethnographic observations, interviews and artifact analysis as the data collection methods and thematic analysis as the data analysis method. Findings The comparative analysis of the normative and descriptive models showed that the underlying normative assumptions of COBie can be challenged in its implementation. In the case study, implementing COBie disrupted the conventional practice of few participating firms as the data requirements and the expected sequences and timelines of tasks were not aligned with the industry norms for exchanging data. Furthermore, the normative model of COBie could not account for the unanticipated variability in the internal routines of firms for submittal production. Practical implications - COBie, as an instruction-based model, may not provide enough flexibility for some firms to adapt to its requirements such that COBie tasks become integrated with their existing workflows. COBie tasks may become additional efforts, and at times, conflict with the industry norms and firms' routines, and therefore, disrupt the efficiency goals. Originality/value This paper provides empirical evidence to clarify why implementing COBie has not been as efficient for all industry players as expected.

Keywords

Construction Industry; Information Dissemination; Information Systems; Cobie; Hand Over; Information And Communication Technologies; Information Exchanges; Operations; Facilities Management; Bim; Construction; Case Study; Information Exchange; Information And Communication Technology (ict) Applications; Project Hand Over

Diverse Approaches to the Preservation of Built Vernacular Heritage: Case Study of Post-Disaster Reconstruction of the Xijie Historic District in Dujiangyan City, China

Kou, Huaiyun; Chalana, Manish; Zhou, Jian. (2020). Diverse Approaches to the Preservation of Built Vernacular Heritage: Case Study of Post-Disaster Reconstruction of the Xijie Historic District in Dujiangyan City, China. Journal Of Architectural Conservation, 26(1), 71 – 86.

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Abstract

Preservation of the built vernacular heritage contributes to maintaining a 'sense of place' and cultural diversity; yet, it is often ignored in preservation practices that favour high styled architectures and monumental sites. In China, although the understanding of the value of vernacular expression has shown some progress, technical and methodological efforts are still necessary to address the diversity and complexity of vernacular heritage. In this paper, the Xijie Historic District in Dujiangyan City in China provides an example for the preservation of the built vernacular heritage in the context of neighbourhood revitalization during a post-earthquake reconstruction project. Five types of intervention are examined in this paper, including the repair and restoration of the monuments, restoration of historic buildings, rehabilitation of traditional houses, contextual design of new buildings, and demolition to provide public space and facilities. In particular, the measures implemented to meet the residents' needs while maintaining the diversity of the built vernacular heritage are inspected. This study concludes with three recommendations: the classification of vernacular environments and employment of diverse measures to each type; the adaptation of the vernacular environment to meet residents' expectations and aspirations; and recognition of the development and reasonable control of the changes.

Keywords

Historic Districts; Preservation Of Historic Buildings; Cultural Pluralism; Preservation Of Cultural Property; Preservation Of Monuments; Preservation Of Architecture; Housing Rehabilitation; Wenchuan Earthquake, China, 2008; China; Built Vernacular Heritage; Community; Diversity; Historic District; Historic Preservation

Differential Associations of the Built Environment on Weight Gain by Sex and Race/Ethnicity but Not Age

Buszkiewicz, James H.; Bobb, Jennifer F.; Kapos, Flavia; Hurvitz, Philip M.; Arterburn, David; Moudon, Anne Vernez; Cook, Andrea; Mooney, Stephen J.; Cruz, Maricela; Gupta, Shilpi; Lozano, Paula; Rosenberg, Dori E.; Theis, Mary Kay; Anau, Jane; Drewnowski, Adam. (2021). Differential Associations of the Built Environment on Weight Gain by Sex and Race/Ethnicity but Not Age. International Journal Of Obesity, 45(12), 2648 – 2656.

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Abstract

Objective To explore the built environment (BE) and weight change relationship by age, sex, and racial/ethnic subgroups in adults. Methods Weight trajectories were estimated using electronic health records for 115,260 insured Kaiser Permanente Washington members age 18-64 years. Member home addresses were geocoded using ArcGIS. Population, residential, and road intersection densities and counts of area supermarkets and fast food restaurants were measured with SmartMaps (800 and 5000-meter buffers) and categorized into tertiles. Linear mixed-effect models tested whether associations between BE features and weight gain at 1, 3, and 5 years differed by age, sex, and race/ethnicity, adjusting for demographics, baseline weight, and residential property values. Results Denser urban form and greater availability of supermarkets and fast food restaurants were associated with differential weight change across sex and race/ethnicity. At 5 years, the mean difference in weight change comparing the 3rd versus 1st tertile of residential density was significantly different between males (-0.49 kg, 95% CI: -0.68, -0.30) and females (-0.17 kg, 95% CI: -0.33, -0.01) (P-value for interaction = 0.011). Across race/ethnicity, the mean difference in weight change at 5 years for residential density was significantly different among non-Hispanic (NH) Whites (-0.47 kg, 95% CI: -0.61, -0.32), NH Blacks (-0.86 kg, 95% CI: -1.37, -0.36), Hispanics (0.10 kg, 95% CI: -0.46, 0.65), and NH Asians (0.44 kg, 95% CI: 0.10, 0.78) (P-value for interaction <0.001). These findings were consistent for other BE measures. Conclusion The relationship between the built environment and weight change differs across demographic groups. Careful consideration of demographic differences in associations of BE and weight trajectories is warranted for investigating etiological mechanisms and guiding intervention development.

Keywords

Body-mass Index; Socioeconomic-status; Food Environment; Obesity; Health; Outcomes; Scale; Risk; Minority & Ethnic Groups; Urban Environments; Etiology; Demographics; Sex; Residential Density; Supermarkets; Age; Race; Ethnicity; Property Values; Body Weight Gain; Electronic Medical Records; Fast Food; Electronic Health Records; Real Estate; Subgroups; Demography; Trajectory Analysis; Weight

Evaluation of Sky Spectra and Sky Models in Daylighting Simulations

Inanici, M; Abboushi, B; Safranek, S. (2022). Evaluation of Sky Spectra and Sky Models in Daylighting Simulations. Lighting Research & Technology, 1.

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Abstract

Sky models in daylight simulations represent the luminance variation across the sky-dome for different locations, dates, times and weather conditions, but skies are typically modelled as colourless. Recent studies explore techniques for incorporating the spectral content of daylighting in simulations. This paper provides an evaluation of the existing spectral sky models in lighting simulation software. The comparisons are made between the available mathematical sky models and naturally occurring skies that were recorded using high dynamic range photography and spectrophotometric measurements. The results show that recently developed sky models present progress compared to colourless sky models, but further research is needed to accurately simulate daylight spectra. [ABSTRACT FROM AUTHOR]; Copyright of Lighting Research & Technology is the property of Sage Publications, Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Organizational Divisions in BIM-Enabled Commercial Construction

Dossick, Carrie S.; Neff, Gina. (2010). Organizational Divisions in BIM-Enabled Commercial Construction. Journal Of Construction Engineering And Management-asce, 136(4), 459 – 467.

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Abstract

Proponents claim that the adoption of building information modeling (BIM) will lead to greater efficiencies through increased collaboration. In this paper, we present research that examines the use of BIM technologies for mechanical, electrical, plumbing, and fire life safety systems (often referred to as MEP) coordination and how the introduction of BIM influences collaboration and communication. Using data from over 12 months of ethnographic observations of the MEP coordination process for two commercial construction projects and interviews with 65 industry leaders across the United States, we find that BIM-enabled projects are often tightly coupled technologically, but divided organizationally. This means that while BIM makes visible the connections among project members, it is not fostering closer collaboration across different companies. We outline the competing obligations to scope, project, and company as one cause for this division. Obligations to an individual scope of work or to a particular company can conflict with project goals. Individual leadership, especially that of the MEP coordinator in the teams we studied, often substitutes for stronger project cohesion and organization. Organizational forces and structures must be accounted for in order for BIM to be implemented successfully.

Keywords

Technology; Implementation; Viewpoint; Integrated Systems; Construction Industry; Leadership; Information Systems; Information Technology; Communication; Constructability; Mechanical Systems; Electrical Systems

The San Francisco Peninsula’s Great Estates: Part I

Streatfield, David C. (2012). The San Francisco Peninsula’s Great Estates: Part I. Eden, 15(1), 1 – 14.

Abstract

The article presents a historical background of several great estates in San Francisco Peninsula in California known for their unique landscaping and special garden designs in the late 19th and early 20th centuries. It discusses the climate and settlement styles in the area and offers information on the earliest estates such as the El Cerrito created by merchant William Davis Merry Howard and the notable mid-Victorian estates such as the Millbrae estate of banker Darius Ogden Mills.

Keywords

Garden Design; Landscape Design; Landscape Gardening; San Francisco Peninsula (calif.); California