Carol C. Menassa

Agent-Based Modeling of Occupants and Their Impact on Energy Use in Commercial Buildings

AbstractEnergy modeling is globally used during the design phase to estimate future building energy performance. Predictions obtained from common energy estimation software typically deviate from actual energy consumption levels. This discrepancy can mainly be attributed to the misrepresentation of the role that building occupants play in the energy estimation equation. Although occupants might have different and varying energy use characteristics over time, current energy estimation tools assume they are constant. This paper proposes a new agent-based approach to commercial building energy modeling by accounting for the diverse and dynamic energy consumption patterns among occupants, in addition to the potential changes in their energy use behavior attributable to their interactions with the building environment and with each other. The impact of an active modeling of occupancy is then illustrated in a case study of an office in a university building, where more than 25% variation in the predicted energy...

A conceptual framework to energy estimation in buildings using agent based modeling

Actual energy consumption in buildings is typically different from predictions during the design phase. While differences in occupant energy usage characteristics play an important role in this variation, actual energy estimation software do not account for this factor. This paper proposes a new approach for energy estimation in buildings using a combination of traditional energy calculation software along with agent-based simulation modeling. First, the difference in energy consumption levels for different types of occupancy energy usage characteristics is identified by building energy models adapted for each type of behavior. Then, an agent-based simulation model simulates the influence that people with different behaviors have on each other, resulting in potential changes in energy usage characteristics over time. By combining these two methods, more customized energy studies can be performed resulting in more accurate energy consumption estimates.

Effect of social network type on building occupant energy use

The energy demands of buildings have been shown to vary considerably due to differences in occupant energy use behavior. In buildings, occupants are subject to social pressures and influences which help moderate what is and what is not acceptable behavior, including energy use behavior. This transmission of social influence and the creation of social norms occur through social networks. Recent research has examined changes in occupant energy use behavior due to social influence through social networks, but has done so considering only one network type at a time. Therefore, this study investigates the impact of network type on occupant energy use behavior and consumption. Agent-based modeling is applied to explore the effect of network type for two separate administrative actions on reducing energy consumption: increasing social connectivity and implementing environmental champions. Results indicate that social network type is not significant in determining mean energy use change, but is when considering the time required for the system to reach equilibrium, through convergence or grouping. Additionally, increasing social connectivity has undesired effects without the presence of environmental champions; however, with them, increasing social connectivity can significantly decrease the time required to realize energy savings and amplifies the reductions.

Study of Real Options with Exogenous Competitive Entry to Analyze Dispute Resolution Ladder Investments in Architecture, Engineering, and Construction Projects

Architecture, engineering, and construction industry participants often find it pragmatic to implement a project-specific dispute resolution ladder (DRL) as a managerial tool to assist in the prompt resolution of claims and change orders (CCOs) that might arise during the project construction phase. This project-specific DRL consists of a single or multiple alternative dispute resolution (ADR) techniques that require capital expenditures to cover the expenses incurred by the owner’s/contractor’s employees and third-party neutrals. If a project-specific DRL is properly chosen, then the capital expenditures are outweighed by the expected benefits from the DRL implementation; namely, prompt resolution of the CCOs without incurring excessive cost overruns on an already financially stressed project budget, as well as avoiding the escalation of the claims to a dispute that requires long protracted litigation for final settlement. Typically, the decision as to which ADR techniques to include in the project-speci...

Recession effects in United States public sector construction contracting: Focus on the American Recovery and Reinvestment Act of 2009

AbstractThe 2009 American Recovery and Reinvestment Act (ARRA) was enacted to support the economy in response to the 2008–2009 global recession. The injection of construction funds into the public sector put pressure on public agencies to award contracts as quickly as possible in an effort to immediately stimulate the economy and help reconstruct the deteriorating infrastructure. This enabled contractors to move from private sector work into the public sector to stay afloat financially. As a result, an increase in competition for public project awards was observed combined with projects being awarded at a fast rate. The main objective of this paper is to investigate evidence of the level of contractor competition and the degree to which public agencies are expediting the award process during the bidding phase on ARRA construction projects. Both positive and negative impacts caused by this dynamic are examined. To achieve this objective, the research looked into the bidding phase of ARRA construction proje...

Insurance as a Risk Management Tool for ADR Implementation in Construction Disputes

Nowadays, along with the inherent intricacy and magnitude of large-scale construction projects come increasingly complex disputes. Because most projects operate on tight budgets, alternative dispute-resolution (ADR) techniques such as negotiation, mediation, and arbitration are being widely adopted in large-scale construction projects to help handle disputes in more effective and cost-saving ways. However, the risk of incurring uncertain ADR-implementation costs in the dispute-resolution process has become an important issue. The traditional self-insured approach of simply retaining all risks is no longer considered economical. One way to reduce the potential for variations in the dispute-resolution budget is to price ADR techniques as an insurance product, which allows project participants to transfer the risk of incurring unexpectedly high ADR-implementation costs to the insurance company. Despite this advantage, many factors are preventing project participants from investing in ADR-implementation insur...

An Agent-Based Approach to Model the Effect of Occupants' Energy Use Characteristics in Commercial Buildings

Energy consumption estimates obtained during the design phase of commercial buildings typically differ from actual consumption levels measured during the operation phase. One important reason for this variation is that energy estimation software (e.g. eQuest and Energy Plus) consider occupants as static elements with fixed schedules and energy use characteristics, misrepresenting the dynamic aspect of their interactions in the building environment and the resulting changes in their energy consumption patterns. This paper proposes a new approach for energy estimation in buildings using agent-based modeling, a technique capable of simulating occupancy in a dynamic manner. First, occupants are divided into ‘Low’, ‘Medium’, and ‘High’ energy consumers. Then, an agent-based model simulates these occupants’ interactions with each other, with the room environment, and with the exterior. Preliminary results show a difference of more than 20 percent in the design energy consumption estimates for a university building office when using the proposed method.

Analysis of dispute review boards application in U.S. construction projects from 1975 to 2007

Since their first successful implementation in 1975, dispute review boards (DRBs) gained popularity as a standing neutral alternative dispute resolution (ADR) technique, and were implemented on a number of high profile construction projects in the United States and worldwide. The purpose of this study is to present a review, trend analysis, and classification of U.S. construction projects that had DRBs for the period of 1975–2007. Thus, a total of 1,042 U.S. construction projects that had DRB as part of their contract provisions are extracted from the Dispute Review Board Foundation database and are analyzed. The results of this study are presented in two major sections. In the first section, results of trend analysis are reported as growth in number of projects with DRB since 1975, as well as the distribution of these projects in terms of construction type (i.e., building, highway, and tunnel), and construction volume category. On the other hand, the second section includes the results of the analysis undertaken to study the mechanics of DRB application in construction projects. In this context, the effectiveness of DRB as a preventive measure against the escalation of conflicts to disputes is first studied. For those projects that had disputes heard by a DRB panel, the data was further analyzed to determine the effectiveness of the DRB as an ADR technique that can help in the resolution of a dispute at the project level without further escalation to arbitration or litigation. The results of the study indicate that DRBs have been successfully implemented in all three construction sectors in the United States. The effectiveness of DRB as a prevention technique was observed on approximately 50% of the 810 projects where no disputes were ever heard through a DRB panel formal hearing. For the remaining 50% of the projects, the effectiveness of DRB as an ADR technique was found to exceed 90% when comparing the number of disputes that were settled due to DRB recommendation to those that were actually heard during a DRB hearing session. Finally, the paper concludes with a set of questions and hypotheses that may be undertaken to explain the recorded observations, and set the way for future research efforts in this area.

Hybrid Model Incorporating Real Options with Process Centric and System Dynamics Modeling to Assess Value of Investments in Alternative Dispute Resolution Techniques

Project-specific dispute resolution ladders (DRLs) are typically implemented in construction projects to resolve issues arising between the project participants. The DRL typically consists of single or multiple alternative dispute resolution (ADR) techniques to address construction issues at the three levels of escalation: conflicts; disputes; and claims. However, a DRL requires significant investments to cover the direct costs incurred in-house by the project participants or, externally, if construction specialists and lawyers are recruited to assist in the resolution. Thus, the benefits of the DRL implementation in a construction project must outweigh its costs for the implementation to be worthwhile. This paper presents a methodology to study the effect of different resolution strategies on the value of the investment in a DRL using option/real option theories from financial engineering, process centric modeling, and system dynamics methodology. Of particular interest in this paper is the integration o...

Sensitivity of Energy Simulation Models to Occupancy Related Parameters in Commercial Buildings

Commercial buildings are responsible for 19 percent of the total energy consumption in the United States (US) and are projected to expand their share of energy use at increasing rates. Saving energy in the commercial building sector has therefore become the focus of many governmental initiatives. The first step towards more energy efficient buildings is improving design. Optimizing the sizing of mechanical and electrical systems is particularly important as it highly affects the buildings’ life-cycle energy use. Consequently, designers and engineers are using energy modeling and simulation to compare different systems and predict building performance. Large discrepancies are however being observed between predicted and actual building performances. In order to improve these predictions, the sensitivity of energy models to different input parameters needs to be evaluated. Although proven to significantly affect energy use, occupancy related parameters have rarely been evaluated. This paper presents a sensitivity analysis study performed on the occupancy parameters of the most typical commercial building type encountered in the United States (US). Results indicate that occupancy chosen building temperature set points have the highest impact on energy use, while the influence of building schedule and after-hours equipment/lighting use is also significant, particularly in hot weather climates.