Posted in practice
on October 1, 2015 9:43 am EDT
IPD & BIM: Better Together
A look at the evolution of collaborative design, As well as the stumbling blocks along the way
The three pillars of IPD
The three pillars of Integrated Project Delivery (IPD) are: 1. new technology; 2. collaborative business processes; and, 3. integrated legal/financial structures. The first pillar, technology, is gaining momentum. Architects are increasingly adopting the BIM: in 2007, only 17% of U.S. architects reported using BIM software, but by 2009 over 80% of the largest architecture, engineering and construction (AEC) firms reported that they had adopted BIM. In part, that’s because big customers, including the General Services Administration (GSA), the U.S. Army Corps of Engineers and the U.S. Air Force, are requiring that BIM software be used to design new projects. Audiovisual and lighting (AVL) designers have followed suit: respondents to a recent informal survey that I conducted were unanimous that they use BIM software.
So far so good? Not quite. The system designers I queried also say that they provide drawings electronically in PDF or occasionally drawing format (.dxf or .dwg) files. This didn’t sound very much like IPD to me, so I questioned a few respondents more deeply. Their answers revealed what happens when one of the three IPD pillars operates without the other two.
The main difference between 3D CAD software (the previous generation) and BIM tools (the current generation) is that when you draw a wall, window, electrical conduit or loudspeaker in a BIM program, you are simultaneously creating a “drawing object” that resides in a database. This can save huge amounts of time when an architectural firm works with one or more design subcontractors on a complex building like a modern house of worship.
For example, a typical ceiling plenum design must accommodate HVAC ducts, electrical conduit, plumbing for fire sprinklers and perhaps other uses, and possibly ceiling speakers for paging and emergency notification. As physical objects, none of these things can occupy the same space. But as 3D CAD drawings on separate layers, they could and did. BIM software can alert the designer to collisions between different drawing layers without requiring manual comparison of these layers. That allows the architect to send an AV consultant, or a mechanical, electrical and plumbing (MEP) engineer, a BIM file with a specific layer or layers unlocked for editing. The design subcontractor edits that layer and sends the file back to the architect for integration into the master. The database does all the tedious checking that none of the electrical conduit is running through a water pipe and none of the water pipes are running through an elevator shaft—automatically. Time, paper and money are all saved through an integrated design process.
When it comes to the construction phase, however, the savings (except for a bit of paper) stop. The contractor receives a PDF electronically instead of a sheaf of paper drawings via courier. Many are still in the process of adapting to this change: one consultant told me, “Almost every time I send a multi-page PDF, I get a phone call asking where the rest of the drawings are."
A deeper problem is that the PDF is as static as a piece of paper. In terms of information flow, nothing has changed. The architect designs the building and then hands it off to the contractor for construction. The only form of feedback is the traditional change request submittal/change order process. Mixing new technology with traditional business processes has already created one very large problem for the designer of a life sciences building at a major university. Using BIM, the architect and consultants packed the ceiling plenum to maximum density: so dense that the different systems had to be installed in a very specific order. Unfortunately, this information was not provided to the contractor, who ran out of space about 70% of the way through assembly. The resulting delays, lawsuits and insurance claims increased the building’s cost and decreased the designers’ profits.
This particular project highlights the need for contractors to update their own software tools and internal processes in order to take full advantage of BIM and move towards IPD. Contractors, especially large firms, are already turning to BIM as they realize that it can cut their time and costs. New tools will help streamline field operations, creating savings that extend beyond the pre-construction bidding stage. For example, Vela Systems, (visit link
), has announced Field BIM-Interactive. The software runs on a variety of platforms, including the Apple iPad, and is compatible with many different types of model files. The Interactive part of Field BIM-Interactive uses BIM objects as gateways to additional data and documents that are stored “in the cloud,” on the Internet. By enabling contractors to bring the visual model to the jobsite, tools like this can help avoid misunderstandings and the consequences.