GIS practitioners in the city planning community are aware of the groundwork being laid to accommodate an ever-growing population. Geospatial tools are now commonplace and are used to plan and police city zones and planning restrictions. Where that planning activity meets the built environment is where we will see geospatial tools interface with building information models (BIM).
We could say that building information models are the operational residue of the architect’s art. But as well as holding the data needed to “remember” where the services conduits are and what capacity remains available within them after first commissioning, they provide a repository for data through all the stages of building work. Facilitating greater cooperation between designers, engineers and construction teams, they typically result in a 3D model of all the structural data needed to build and run a modern building efficiently.
During the design and construction phase, building information models can provide the basis for simulation exercises that ensure last-minute alterations to plans cause minimum disruption to the schedules. Running costs can be calculated based on the planned work-for example making sure that the exact combinations of heating, ventilation and air conditioning systems are optimal for the building’s planned use. The goal is to prove as much as possible of the design and reduce the need for corrective work onsite.
When developed alongside the geospatial data that sets the real world context for the building and that can analyze the services supplying the building, the two become crucial to successfully running the site. Of course BIMs are not restricted to buildings-any project involving the built environment benefits from the visualization and operational simulation that is offered by BIM tools, whether for an office block or a motorway bridge. As the development goes operational, the BIM lives on to provide a starting point for managing the site and a repository for ongoing maintenance data.
This collaboration and integration between individuals in the building phase seems to be something of a new departure for those disciplines. But the GIS practitioner is used to integrating with other agencies. The highway authority is continually exchanging data with water companies, energy suppliers and telecom operators so that their buried assets can be avoided by the next team to dig up the road. Indeed, utility providers in many territories are under regulatory obligation to provide data on the location of their wires and pipes. Is BIM simply providing the next level of integration that adds building elevations to their footprint and takes us inside buildings to see, for example, exactly where the external power lines connect to the building substation?
The advantages of such a level of integration with the built environment are many; indeed, urban models are beginning to be developed and could be used to optimize the operation of a whole community. Building on agreed protocols that enable software tools from widely differing backgrounds to interact, as with the CityGML specification maintained by the Open Geospatial Consortium (OGC), city models are being developed. An example is the digital cities research pilot in Saltzburg. This is an attempt to draw together workflows for geospatial features, planned building construction, and utility assets into a single base for urban planning. Once in place, it can be exercised for the good of the community in many ways. An oft-cited use of such a city model is the fly-through that is used to look for sniper vantage points along the walking route of a visiting public figure. Or consider the current example of collaboration between construction data and geospatial data that can be seen in projects in Lower Manhattan, New York. This combines up-to-date traffic information with construction project status and delivers it-among other ways, I am sure-through a web page that advises members of the public of likely disruptions to their daily commute.
Managing and delivering up-to-date traffic information is not a new trick for entities with a decent GIS and the will to make the data public. What is interesting is that the use of a BIM by the construction projects in the city enables their activities to be plotted into the traffic plan for the day. So now the city can show planned changes to road closures, for example because of the arrival of a mega-crane on site, and not just report on road blockages or increased density in traffic.
All this data sharing and collaboration sounds fine, but in practice the geospatial side and the design and construction sides are still operating in isolation. One reason for these silos may be the lack of a long-term, economic driver for creating and maintaining building information models or city information models. Government initiatives and regulations are important in this area, driven in turn by the need to be more efficient in the use of resources by reducing waste and conserving energy. The UK government, for example, requires all publically funded infrastructure projects to use building information models-that is, an electronic version of all project and asset information-by 2016. The goal is to introduce savings and provide a source of data for integration with equivalent (geospatial) data from highways, transportation and energy projects.
Interestingly, the UK initiative does not prescribe the use of BIM tools, but rather the creation of electronic data. This lines up with the theory that BIM isn’t about a single toolset but is rather a process that involves managing information models of the built environment-IMB rather than BIM, perhaps.
The benefits are most closely seen in the running of the building, and in these projects the government body is that building owner or operator. The same benefits could be available to the private building owner/operator, but for the private operator, it is not so simple to prescribe the use of BIM. The architects and developers may have little or no relationship with the eventual building owner or operator, so incurring the cost of capturing full BIM data may be harder to justify. Until it becomes accepted good practice, the appearance of BIMs will be patchy. But with governments providing the example of savings that can be achieved, delivering a completed BIM may well become an asset of the development as delivered. When that happens, the geospatial practitioners need to be ready to accept that data into their view of the world.