Immersive virtual environments versus physical built environments: A benchmarking study for building design and user-built environment explorations

Highlights

• Office-related performance is similar in IVE and physical environments.

• Sense of presence in IVE is strong and similar to physical environment.

• IVE can be used to gain end-user feedback to improve design evaluation process.

• IVEs are effective tools to measure human behavior in real-world settings.

Abstract

In order for a project to be satisfactory to end-users and completed with high quality, the architecture, engineering, and construction (AEC) industry heavily relies on digital modeling, simulation and visual communication. In the past two decades, the AEC community has examined different approaches, including virtual and augmented reality, to improve communication, visualization, and coordination among different project participants; yet these approaches are slowly being adopted by the industry. Such technological advancements have the potential to improve and revolutionize the current approaches in design (e.g., by involving end-user feedback to ensure higher performing building operations and end-user satisfaction), in construction (e.g., by improving safety through virtual training), and in operations (e.g., by visualizing real-time sensor data to improve diagnostics). The authors' research vision builds upon the value of using immersive virtual environments (IVEs) during the design, construction, and operation phases of AEC projects. IVEs could provide a sense of presence found in physical mock-ups and make evaluation of an increased set of potential design alternatives possible in a timely and cost-efficient manner. Yet, in order to use IVEs during the design, construction, and operation phases of buildings, it is important to ensure that the data collected and analyzed in such environments represent physical environments. To test whether IVEs are adequate representations of physical environments and to measure user performance in such environments, this paper presents results from an experiment that investigates user performance on a set of everyday office-related activities (e.g., reading text and identifying objects in an office environment) and benchmarks the participants' performance in a similar physical environment. Sense of presence is also measured within an IVE through a set of questionnaires. By analyzing the experimental data from 112 participants, the authors concluded that the participants perform similarly in an IVE setting as they do in the benchmarked physical environment for all of the measured tasks. The questionnaire data show that the participants felt a strong sense of presence within an IVE. Based on the experimental data, the authors thus demonstrate that an IVE can be an effective tool in the design phase of AEC projects in order to acquire end-user performance feedback, which might lead to higher performing infrastructure design and end-user satisfaction.

Introduction

The cost and complexity of design changes exponentially grow as a project progresses from the planning and design phases to the construction phase; therefore, early design decisions in a project's life impact overall project costs and end-users' satisfaction significantly. In recent years, Building Information Modeling (BIM) has been widely adopted by the AEC industry. As a result, there has been a significant amount of improvement in communication, exchange and interoperability of information among different parties involved in a project [15]. However there exists a lack of end-user involvement during the design process, which has been identified as one of the major issues in current design approaches [11]. User Centered Design (UCD) has shown to be an effective approach to improve the final product based on end-users' needs in many domains, including software design and the automotive industry. Taking the UCD approach used in other industries, Bullinger et al. and Zahedi et al. [11], [70] proposed the concept of involving users and acquiring end-user input early during the design phase in order to increase efficiency, quality, and performance of Architecture Engineering and Construction (AEC) projects. However, due to the lack of time and resources, as well as the growing number of parties involved in design and construction phases of AEC projects, end-user involvement is usually minimized and in many cases eliminated [50].

In the past few decades, augmented reality (a physical environment, whose elements are augmented with and supported by virtual input), virtual reality (a simulated virtual environment, representing a physical environment), and immersive virtual environments (IVEs — environments where user interaction is supported within a virtual environment) have given many opportunities to the researchers in various domains, such as the education, health, automation industry, and the military, to increase user involvement and improve the efficiency of their work processes. Similarly, the AEC community has also adopted the use of virtual reality [35], [61] and augmented reality [7], [10], [25] for supporting various construction and building simulations and information visualization [2], [6], [19], as well as coordination and collaboration among teams [32], [40], [55], [63]. Although the AEC industry has used IVE technologies before (e.g., CAVE and Head Mounted Displays), their primary use has been limited to marketing purposes, visualization of BIMs [11], and education and training of AEC professionals [54].

An IVE can be utilized for engaging end-users in the design process of projects by combining the strengths of pre-construction mock-ups that provide a sense of presence to users and BIM models that provide the opportunity to evaluate alternative design options in the models in a timely and cost efficient manner [26], [41]. Furthermore, building engineers and designers can incorporate IVEs in their work processes as a tool to measure end-user behavior, understand the impact of design features on behavior, as well as receive constructive user feedback during the design phase. The use of IVEs is not only limited to the design phase; such environments can also be used as cost effective and efficient tools during the construction phase to improve site preparation and logistics, safety and training of construction workers [46], [66], and collaboration and coordination among team members. IVEs can also be used in the operation phase of buildings to visualize and interact with sensor data available in buildings, and for personnel training and process improvement purposes during building operations [14].

The work presented in this paper builds upon the value of integrating IVEs to explore and address different challenges within the AEC industry, such as user input in early design decision making stages, design alternative evaluation, evaluation of safety measures on a construction site, or emergency response operations in post-construction phase. The authors' long term goal builds on the following research question: “how can we better test project design alternatives and measure user behavior and performance in different alternatives through the integration of immersive virtual reality into our digital and physical mock up workflows?”

In order to achieve this long-term goal, the authors aim to test whether IVEs are adequate representations of physical built environments and to measure user behavior within various settings (e.g., different lighting settings). As the first step, it is imperative to evaluate end-users' performance and sense of presence within IVEs and benchmark them to similar physical built environments. This paper specifically presents results from a comparative study, where the authors evaluated the end-user's performance on a set of identical tasks in immersive virtual and physical office environments with the same features.

The paper presents the research through a literature review and gap analysis on the use of virtual reality and IVEs for integrating end-user feedback during the design phase, as well as their uses in general within the AEC industry. The paper presents the research methodology, the IVE system for data acquisition, and detailed results and discussion of user performance in everyday office related tasks, through metrics of response–time and performance accuracy, within an IVE compared to a physical built environment setting. Finally, the paper is concluded by a discussion and presentation of the planned future work.