This scenario is all too frequent on a busy construction site. Shuffling materials and plant around a cramped site because of poor space planning can add days to an already tight construction schedule. It is a problem of which Professor Brian Hobbs, director of research and development at the Research and Development Office of the University of Teesside, is all too aware: "As most buildings are unique, a perfect plan for construction is often only achieved after the project is completed and delivered," he explains. "The industry practises on its customers' time and money".
In a bid to improve the situation, Hobbs and his team at the university's Virtual Reality Centre are working with the Bartlett School of Architecture at University College London and the University of Wolverhampton to devise a software program that will enable a project team to practice the construction of a building before a brick has even been laid on site.
The Virtual Construction Site, or Vircon as it is known, will offer contractors the potential to visualise and analyse the entire construction sequence, from excavating the foundations to installing lightning protection on the completed roof, all on screen.
Managing space on site is the starting point for the Virtual Construction Site. "What is usually ignored in construction planning is that task execution occupies space," says Hobbs. "Space occupied by one task is often not available either for the execution of other tasks or for the movement of materials, people and plant." But inefficient planning of a construction site not only leads to lower productivity, it also has important safety implications. Hobbs says research at UCL has shown that many accidents can be attributed to poor site logistics.
"Currently, the management of this space relies on the experience and intuition of project planners," he explains. With the increasing skills shortage in the industry, many project planners and construction managers lack experience of the diverse range of operations that can take place on a construction site.
To explore the relationship between space and on-site activity, Hobbs used the £10m School of Health that was constructed at the university as a pilot project. Working with the construction team, he used BRE's CaliBRE project monitoring system to record the time and space taken for a particular task. This information can then be moved to Hobbs' virtual construction site.
Hobbs' team is attempting to adapt software developed by the Bartlett School to model the movement of people around buildings and urban areas to enable it to model how the space changes on a site as a building is constructed, something he refers to as "critical space analysis".
"The critical space analysis tool will allow the network of spaces that comprise the construction site and partially completed building to be represented and analysed stage by stage," says Hobbs. This will allow project planners to monitor the changing amount of space available as the building is erected.
Once this critical space system has been developed, the team will combine it with critical path analysis software. The latter is already widely used by industry to model the order in which a project has to be constructed; for example, the windows can be installed only after the walls are finished. With this combination, the team hopes to produce a project-planning module that will link space and time on a construction project.
To model a particular project, all that remains is for the geometry of the building to be defined using CAD drawings. The programme will then attach spatial information to each element including the working area needed to construct it, materials storage space and access requirements for men, machinery and materials. Using virtual reality techniques, the project team will be able to practise constructing a building in the warmth of the office until the most efficient method is achieved.
When Hobbs and his team have finished the software, planners will be able to see the knock-on effect on the construction programme caused by changing a task early on. They will also be able to view a snapshot of the construction site at any point in time and, where a bottleneck is identified, it will allow planners to reschedule the construction programme to eliminate it.
Viewing the project as it progresses will also help the project team spot any activities missing from the programme, help ensure that communication is established between specialist contractors working in the same area and ultimately reduce the resources needed to manage a construction site. The software could eventually be developed to suggest possible solutions to spatial conflicts.
Hobbs anticipates that the team has another two years of development work ahead of them before the software will be ready to be rolled out to industry. "The ultimate aim of the research is to provide a desktop strategic-decision-support tool as a construction-planning aide," says Hobbs. However, the system may also be used at the University of Teesside's virtual reality auditorium, where an entire team could be introduced to a project and its proposed construction sequence while actually walking through the virtual building.