PREFAB, BIM and IPD

With the announcement last week that the world’s tallest prefabricated steel structure, a 34-story entirely prefab affordable housing tower, will be erected in the Atlantic Yards project in Brooklyn NY, it’s an opportune time to touch on the subject of prefabricated architecture and its relation to BIM and IPD.

I’m in Mexico this week surrounded by prefab housing so am thrilled to have someone fill in for me who’s an expert on this subject and believes the strategies of IPD and BIM are integral to the success of modular and prefab.

Who better to address this topic head-on but my friend and guest-blogger, Ryan E. Smith, the Director of Integrated Technology in Architecture Center (ITAC), an interdisciplinary research group dedicated to lean and sustainable design and construction.

Ryan also happens to be the author of the excellent and well-researched Prefab Architecture: a guide to modular design and construction (Wiley, 2010). Thanks Ryan!

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Modular Lessons Learned: Context, Integration and Technology

After researching and writing Prefab Architecture: a guide to modular design and construction, I have often been asked by architects that if I had to list the most important lessons learned on the topic of modular, what would they be.  Nobody actually wants to read the book; there are frankly too many words and not enough pictures for most architects’ taste.  In all seriousness, the following is a response to architects who are interested in designing and constructing with modules.  You might call this “modular lessons learned.”Lesson 1 – Context Matters

Technology is not deterministic, rather is affectively determined by societal values.  Prefabrication, more specifically modular, as a technology emerges from social and cultural needs and desires.  The environmental contexts in which modular can be categorized include team, type and location. 

Team:  There are a few factors that determine whether a project team will be more or less likely to employ modular.  These determinants include – previous experience with prefabrication and working in integrated teams; control demands by complex, budget restrictions, or other pressing project factors; project teams working on a series or sequence of buildings; manufacturing process and principles exposure; and financing freedom for early factory payout. 

Type:  Project type can determine the degree to which prefabrication is employed.  For example, projects that are under extreme schedule constraints benefit from reduced duration offered by modular.  Also, projects that are repetitive – harnessing mass production or highly unique – harnessing modular’s quality control characteristics may both demand modular employment.  Certain projects require traditional multiple prime contracts, decreasing the opportunities of modular that require early project team engagement and design assist.

Location: Perhaps the greatest determinant in utilizing modular construction, is the geography of site; the building site proximity to manufacturers, materials, and local labor.  Sites that are remote or densely urban are perhaps the best candidates for modular construction.  Conversely, sites that are open, accessible, and in close proximity to many methods of manufacture, material and skilled labor are difficult to justify offsite modular.   

Lesson 2 – Integration Matters

Just as important lesson for modular employment is the collaborative context of the team in which the project is realized.  Early determinations of the potential to use modular require input from both the design and production teams early in the process of delivery.  This suggests utilizing integrated and lean delivery methods for successful modular design and construction.  The earlier in the project that decisions regarding offsite modular can be made, the more positive the impact for schedule, cost, quality and risk. (below)   

Contracts:  Design-build (DB) contracts reduce the overall project duration and have been found to support modular construction projects positively.   Integrated Project Delivery (IPD) takes the desirable elements of both design build’s speed and information sharing and performance contracts, which emphasize outcomes via shared risk and incentives.  IPD supports designers and constructors working collaboratively to provide preconstruction services including cost estimating and constructability reviews, thereby integrating the activities of each project team player with the others.  Ironically enough, the AIA developed their series of IPD contracts AIA295 and SPE from product design and production deliveries such as the automotive industry – not far in methodology from modular.

Leaning Design & Construction:  IPD is primarily a relational legal framework that aligns the interests of project participants with those of the owner.  Lean construction theory was developed years before research on relational contracts that is primarily a map of a collaborative process that aligns the collaborative project organization and the project operating system – made to work in any contractual environment. This approach is in contrast with efforts that start with issues of motivation and contract and never come to grips with the work itself. Leaning the design and construction process therefore uses principles necessary for successful modular deployment including:  Target Value Design (designing to a detailed cost rather than cost estimating based on a detailed design) and Set Based Design (entertaining multiple solutions and not deciding until the last responsible moment)

Lesson 3 – Technology Matters

Despite the fact that technology dominates our buildings, our practices and our lives, architects know relatively little about it.  Two technologies have been touted for their potential to fundamentally reconsider architectural practice: CNC and BIM – both are integral to modular delivery.

Standardization to Automation:  Manufacturing has progressively moved in the following manner – industrialization (c.1850), standardization (c.1900), mechanization (c.1900), mass production (c.1925), automation (1950), & mass customization (c.1990).  Automation and mass customization utilizing computer numerical control (one tool for flexible outputs) exploits an economy of scope.  This is in contrast to standardization and mass production’s economies of scale.  Although computer controlled machinery is more sophisticated and accessible to the building industry than ever before, its deployment is perhaps more appropriately called mass personalization, where customers personalize predetermined configurations.  The goal of mass customization is to meet the needs of clients without sacrificing efficiency, effectiveness and affordability.   This is where modular shines.

BIM:  The future of modular relies on the success and ubiquity of BIM.  Linking time and three-dimensional information, simulation of construction in modular can anticipate schedules from factory workflow to onsite jobsite assembly sequencing.  BIM allows for interface of automation equipment to virtually remove the shop drawing phase and have multiple manufacturers producing modules for onsite assembly.  This may take the form of a building model that is further detailed or networked with other aspects of production and construction by the modular manufacturer.  Building modular parametrics has not occurred to date in the industry but is expected to be a reality in the near future realizing the same productivity benefits the steel industry has found with BIM and CIS2 workflow.   Conclusion

The environmental context of team, project type, and site location are not alone in determining modular employment any more than integration process and technology – all three “matter” or are meaningful in creating value for project stakeholders.   Specifically, the strategies of IPD and BIM are integral to the tactic of modular, making its adoption more rapid across the building industry. (above)   IPD and BIM suggest a restructure of workflow allowing for an information and knowledge transfer through formal operating system and commercial terms.  Although modular design and construction will not solve integration problems alone, it is one of the arrows in the quiver of the integration paradigm that may be used to realize reduced durations, increased quality and controlled cost.  In order to realize these benefits, it demands an early integration effort and information sharing.  Altogether this potentially results in lower risk for all involved.  In the end, modular design and construction is only as good as the demands placed upon it by architects – this requires deeper knowledge.

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Ryan E. Smith is Director of an interdisciplinary research group dedicated to lean and sustainable design and construction inquiry called the Integrated Technology in Architecture Center (ITAC).  He is a researcher, educator, author and speaker on the integration paradigm and building technology.  He is author of Prefab Architecture: a guide to modular design and construction published by Wiley in 2010, serves as the educational liaison on the AIA Center for Integrated Practice Leadership Group, and is a member of the Lean Construction Institute.  He is currently President of the Building Technology Educators’ Society (BTES), an academic group of building technology and building science educators.