| About fifteen years ago, a fellow architect and I imagined a design tool that allowed users to interact with their designs through virtual reality and to manipulate environments by using virtual reality gloves. We envisioned them being able to move a window to get a better view by “grabbing it” and moving it to the desired location, and simultaneously the building plans and elevations would be updated. With critical design issues such as a hospital operating room, a surgeon would be able to see the planned environment and customize the design rather than retrofit the room after construction.
The “computer gods” have made this tool available. An Autodesk product named Revit (for revise it) it is a parametric design tool that promises to revolutionize the design and construction process.
Designing with Revit
We in PB Buildings use Revit in most of our design projects. At the beginning of design, we develop conceptual massing alternatives that translate our client’s space and functional objectives into a three-dimensional stacking and blocking model. From this model we can output building information data that lets us know how much area is dedicated to the exterior envelope (walls and roof) and to functional program space (net area) as compared with total building area (gross area). This information allows us to determine which alternative is the most efficient from a building surface perspective and which provides the most useable area.
In the context of existing buildings, these massing models give us the ability to determine which alternative or combination of alternatives may provide the opportunity to create the most desirable contextual solution. Using commercial software, we can analyze our massing model alternatives to determine which alternative may be the most energy efficient.
As we move into schematic design, we convert our three-dimensional massing alternative into a true building model. With the toggle of a switch we designate the type of exterior wall construction, floor construction, roof construction and interior wall construction. We add the structural system (columns, bearing walls and such); interior components, such as doors, plumbing fixtures, fixed equipment, stairs and elevators; and then begin to articulate the exterior skin with fenestration (windows, curtain walls, doors, etc.) and materials/patterns. This building model can then be viewed in isometric or 3D perspectives to give us an understanding of how the building looks and feels from both the outside (Figure 1) and inside. With another flip of the switch, Revit will produce a listing of material/systems quantities that we can export to cost estimating software for an estimate of the construction cost (Figure 2).
As the design is developed, these interior and exterior perspectives allow us to test shapes, textures, patterns, color and light and to determine the visual impact of our design decisions before the space or building is constructed. With the aid of a simulated walk-through (or fly-by) we can show our clients what it will be like to enter the building and walk through the spaces, or drive around the building (Figure 3).
Recently when designing a library, we placed a virtual camera behind the librarians’ circulation desk to confirm clear sightlines through the library. During this simulation, the librarian asked that we rotate some of the book stacks to allow her to see between them. Without this visualization we (owner and architect) may not have noticed that the sightlines were compromised until after the space was complete and the stacks installed (Figure 4).
Construction Documents
As we build our virtual building, Revit can be useful in pointing out conflicts (e.g., having tall window overlapping with the floor assembly above) that must be corrected before proceeding (Figure 5). This type of interference checking is invaluable in reducing inconsistencies in the construction drawings.
One area where a conflict might occur is the ceiling cavity where structural systems coexist with the mechanical ducts and piping, electrical lights and distribution, water supply and drainage, fire protection systems, and ceiling suspension system or framing. Currently, Revit is being expanded to include such elements so it will soon be capable of performing full building documentation and interference checking.
Another feature that Revit offers is drawing coordination. How many times have you looked at a set of drawings and the detail key refers you to the wrong sheet of drawings? Not so with Revit. This program ties the detail symbols to the drawing where the symbol is located so, if in the heat of putting the drawings together, one decides to add a new drawing and renumber the subsequent detail sheets, Revit automatically renumbers reference details to reflect current drawing sheet numbers. This is a great time saver.
Construction
Revit creates a parametric three-dimensional model that allows users to slice through the building and look inside along an infinite number of planes (Figure 6 on the following page). The construction team could query the model for dimension and material types or look at various design conditions rather than interpolate the construction drawings to determine design intent. This ability is not unlike the way buildings were constructed during the Renaissance, when the master architect used models to explain the building design to the craftsmen who were doing the construction work.
Another Revit feature is its ability to assign construction phases to the building model so users can see what the building will look like at the conclusion of any of these phases. Contractors can use this information to schedule their work and develop methods for constructing the project efficiently and effectively, as it is far easier to do if they can see the desired result as opposed to reading about what is intended (Figure 7 on the following page).
Post Occupancy
Owners are provided with “record drawings” that illustrate changes made in the field during construction. Often these are in digital format with the contractor’s field markups having been transferred from paper to CAD. With Revit, the process would be similar but the end result could be a significant improvement over the traditional CAD files. Building components would be tagged with information about when they were installed and when they should receive regular maintenance, and the owner could extrapolate a planned maintenance schedule for all building systems directly from the Revit model.
Another use of the Revit model is for facilities management functions. Information such as all the furniture owned or located in a particular building or department or the useable area that is “rented” to a department could be entered on the model. For facilities in which staff members are relocated fairly frequently, Revit could be used to track an owner’s inventory of furniture, equipment and rented space. Such information would enable the owner to maximize its use and reuse of the existing furniture and equipment, and to properly “invoice” a department for the space it actually uses (Figure 8). Tie this capability into an energy management system, and we could now “invoice” a department for the amount of electrical energy it uses for light and power or mechanical energy it uses for heating and cooling. Revit has the potential to offer significant possibilities for cost recovery and efficiencies.
Conclusion
Revit is a remarkable tool that integrates design, documentation, visualization, and information into a single cohesive model. The power of Revit is being harnessed by the PB Buildings design group located in St. Louis, Missouri and our architects working in the UK. Current projects include Hazelwood Middle School, a prototype school for 900 students in grades 6 through 8; Sparks Transit Facility, which is a bus transfer complex outside of Reno, Nevada; Pinellas Suncoast Transit Administration Office and Maintenance campus in Collier County, Florida and many more.
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