a b s t r a c t ：Recently building information models have substantially improved the explicit semantic content of design information. Information models are used to integrate the initial phases of project development. On the con- struction site, however, the designs are still mostly represented as line-based paper drawings or projections on portable displays. A generic technology that can integrate information and situate it in time, place and context is augmented reality. The specific research issues addressed are (1) does augmented reality have a potential use in civil engineering, (2) how big – in comparison to other technologies - is this potential and (3) what are the main barriers to its adoption. The generic research issue was to develop a methodology for eval- uation of potentials of technology. A prototype was built. It was tested on a real construction site to evaluate the potential of its use using the action-research method. A set of structured interviews with potential users was then conducted to compare the prototype to conventional presentation methods. Using this methodol- ogy it has been found out that augmented reality is expected to be as big a step as the transition from 2D line drawings to photorealistic 3D projections. The main barrier to the adoption is immature core virtual reality technology, conservative nature of construction businesses and size of building information models.

1. Introduction

Tools for designing in construction have evolved through history. Pens, pencils and paper have been replaced with CAD (computer aided design) and BIM (building information modelling) software. Engineers, builders, planners and contractors also use various domain specific software to support their work. A priority for construction in- formatics research and practice has been to effectively integrate the construction processes using information technology [12]. Adequate standards, e.g. Industry Foundation Classes (IFC), have the potential of solving the problem of interoperability of software and represen- tation of information in designing [15].

While the design phase is largely digitised and increasingly inte- grated around BIM, for a complete digitalisation of construction in- dustry, structured information models would need to be available on construction site where the information is used to shape mate- rial world. However, on the construction site the IT infrastructure is not readily available. Things began to change with the introduction of mobile computing [10]. The field is still evolving.

1.1. Motivation

The outputs of construction information processes (designs, plans and  schedules)  provide  the  control  information  for  the material processes in construction [42]. The media to bring the information from the digital models to construction site where it is used to shape physical reality are still 2D documents such as floor plans, cross sec- tions, sketches, etc. The construction site is integrated into the con- struction process using media and formats that pre-date computers. Situating information and establishing the relation between the real world of the construction site and design information remains the task of humans. In this task they are not assisted much by technol- ogy. Relevant information from the model has to be extracted, based on the user’s role in the project, location and time. The graphical rep- resentation of this information in 2D must be situated and contex- tualised with the physical 3D reality for which people rely on their spatial awareness. It is the technologically largely unassisted human mind that is bridging the gap between the real world of the construc- tion site and the virtual world of the information model and is in- tegrating the two. This is what engineers on site have been doing since the introduction of drawn design information centuries ago. The problem at hand is how to assist this process with technology.

The hypothesis of our research of augmented reality (AR) was that by using a synthetic environment that enables the integration of 4D building information models into the live picture of real world it is possible to improve the understanding and ease the use of project information. It should be possible to measure this improvement.