What is Revit?
The fire sprinkler industry has historically been slow to embrace new technologies, especially when they pertain to system design and layout. Even today, while most of the trade is working in CAD, there are still many construction document sets being drafted by hand and not just on smaller projects. This isn’t an impeachment of the quality of those designs – some of the industry’s very best design technicians are from the “old school”. But insistence on analogue drafting leaves the design/build fire protection team outside the mainstream of current practices and reinforces the notion that fire sprinklers are the problem child of the design/build family.
In the past few years, most contractors and engineering firms that offer fire sprinkler design have adopted one of the several optimized CAD programs that are available to the trade. By combining drafting, hydraulics and material listing functions, these accessory programs add efficiency and value to the exercise of system layout. The development of the software Navisworks® allowed line-based 2D CAD files to be combined and projected as 3D images of what overlaid building and its systems. That was the onset of what we now generically refer to as “BIM Coordination” and “Clash Detection”. But even when projecting 3D images, CAD is still a 2D platform and true BIM (Building Information Modeling) can only be accomplished with 3D drafting.
The first commercially published 3D design software packages were Inventor® and SolidWorks®, both of which are optimized for and widely used in manufacturing industries. In 2000, a new program was released called Revit®, a contraction of Revise-It. Revit® differs from CAD in that it utilizes a parametric engine using proprietary technology, and is infinitely scalable because it is object-based, rather than line-based. Before the term BIM was adopted, the output was referred to as a PBM – parametric building model, because changes to any of its parameters drove changes to the entire model, not just its individual components or systems. Now, all of the inserted parts of the model could be coordinated, clash-detected and revised together, because once assembled, they could be managed and modified together.
The early versions of Revit® were cumbersome and extremely labor-intensive. However, the deliverable building models were so much more comprehensive than CAD-based documents that a move began in the community of project owners to request that their designs be delivered in Revit®. Today, throughout the built environment, more than half of all government agencies, institutional and educational clients specify Revit based designs and the percentage of private projects is growing exponentially. In the past five years, Revit® has steadily displaced AutoCAD® as the drafting platform of choice in the Architectural and Engineering (A & E) communities; even when not absolutely required on a project, drafting in Revit® and down-saving files to CAD formats renders a better product. Currently, more than half of Protection Design’s projects are being designed in Revit®.
But the fire sprinkler industry continues to lag behind, and we’ve seen comments in print from contractors who dismiss Revit® as a “fad”. There are legitimate concerns regarding optimized accessories to be sure – no calculation or listing modules are available and both the learning curve and labor-intensity of Revit® are measurably greater and more expensive than CAD-based drafting. But the capabilities of coordination of the work of many disciplines concurrently and parametric change propagation are beyond comparison with CAD; this is what BIM was intended to be.
As Revit® flows into the A & E sector, more and more content has been and continues to be developed for various trades: websites such Revitcity.com, BIMCity.com, BIMobject.com and others offer free and fee-simple objects for Architects, Structural, Mechanical, Electrical Engineers and other disciplines. But sources for fire protection content are still few, and mostly restricted to manufacturers and suppliers who offer objects at low levels of detail, often referred to as “skins”. As client demand for Revit® based design increased, our firm set out to create a proprietary library of object “families” and today, we are one of the only fire protection design firms in the Southwestern USA with the capability to delivering a complete set of water-based fire protection system construction documents in Revit®. As the architectural community evolves into an exclusively 3D environment, Protection Design is at the cutting edge of this change. The resulting work product is a measurable improvement over CAD - many of our projects are now coordinated by the design team until they can be reasonably declared “clash-free”. Over the next two to three years, we anticipate that the percentage of our work drawn in Revit® will grow to over 90%. We also expect that the process of project management will streamline as detailed coordination by design teams allows fewer field conflicts and constructability issues to manifest during construction.
Perhaps the biggest challenge with Revit® is file size. Because objects are individual files, the compilation of a drawing file with dozens and hundreds of other files creates models that can be enormous compared to line-based CAD drawing files. As Autodesk (now the owner of Revit®) improves and refines the platform, file sizes are becoming more manageable, additional information (called “attributes”) can be assigned to objects and families. The amount of information that can be encapsulated and delivered to owners, managers and tenants of throughout the built environment is almost limitless. Revit® models will allow forecasting of projected maintenance, energy efficiency and costs, water consumption, even wear and tear on building fixtures. Already, publishers of fire protection accessory software are working on hydraulic calculation modules for Revit® and other add-ons. In the foreseeable future, we anticipate for fire protection systems that cost-estimation, inspection and testing programming and even seismic engineering tasks will be undertaken in Revit® and delivered to building owners in the final model. It’s a long, LONG way from pencils and vellum to be sure.
Protection Design and Consulting is your BIM and Revit® resource for fire protections system planning, design and project management.