Tammy McCuen

Tammy McCuen is an assistant professor of construction science at the University of Oklahoma, College of Architecture, with a teaching and research emphasis in BIM. She is currently working on a joint project between the Association for the Advancement of Cost Engineering International (AACEI) and the National BIM Standard (NBIMS) Committee, which are working to define the detailed quantity take-off and cost estimating process in BIM. Prior to joining the OU faculty, McCuen spent 14 years as a cost estimator, superintendent, project manager, and an owner of a construction management company. She is a member of the buildingSMART alliance and the National Institute of Building Sciences. She may be reached at tammymccuen@ou.edu .

This article examines two software products from WinEstimator Inc. (WinEst) that are designed for cost estimating in building information modeling (BIM). DesignEst Pro is best suited for the integrated project team or a design-build project, and Intelligent Takeoff (ITO) is designed for the construction estimator. Also in the article, WinEst President Steven Watt provides insight into the company's approach to creating an estimating solution for BIM that the estimator can rely on for data to produce accurate estimates of project costs. 

The need for accurate cost estimates in BIM is gaining momentum as the value of BIM increases across the U.S. building construction industry. Architects, engineers, contractors, and owners are adopting BIM as a means to better communicate and improve productivity by using the information available in a data-rich model. 

Sixty-one percent of survey respondents for the 2009 McGraw-Hill SmartMarket Report, entitled "Business Value of BIM," identified "improved budgeting and cost estimating" as factors influencing the adoption of BIM. Sixty-one percent is a significant share, and consequently software vendors are taking notice of and developing new solutions for cost estimating in BIM.

The cost estimator's job is to produce accurate cost estimates and is the driving factor in estimators' decisions to implement BIM. What does it take to produce an accurate cost estimate, though? It begins with an accurate quantity takeoff created using processes and methodologies accepted by the profession as recommended "best" practices. As the number of software vendors marketing estimating solutions increases, estimators are discovering that often the software for estimating in BIM does not follow a standard process for quantity takeoff or a methodology for costing that is considered accurate and reliable. Cost estimating is much more than the quantity takeoff, but the quantity takeoff has become the critical point at which estimators lose confidence in BIM. The lack of confidence in BIM solutions for cost estimating has made many estimators hesitant and resistant to the idea of adopting BIM to complete their tasks. 

The issue is not that current BIM estimating products are unable to perform a quantity takeoff, but rather that the data extracted from the model for estimating is considered unreliable. Reliability is at the forefront of estimators' concerns with the data in BIM because no industry-wide standards exist to define the level of detail or methods for measurement followed during the model-generation process. Inherent in estimating is uncertainty about many things -- economy, weather, resources -- and are all items estimators can tolerate being uncertain about in their day-to-day tasks. 

However, reliability of the data in a traditional quantity takeoff is one aspect of the estimating task that estimators have controlled in the past, using processes and methodologies accepted as standard practices. The data has been considered reliable in a non-BIM quantity takeoff process because an estimator controlled the process from beginning to end. Quantity takeoff in BIM does not follow this same process as estimators receive data from a model in BIM instead of generating data from traditional construction documents. BIM solutions vary greatly in their approach and quantity takeoff process. This article focuses on two BIM solutions offered by one software vendor, WinEst, a company dedicated to the quantity takeoff and cost estimating tasks in the AEC industry.    

WinEst focuses on cost estimating and offers various solutions that are designed to meet the needs nationwide through products tailored to generate the different types of budgets and estimates for projects across all phases of a project. WinEst products are multi-dimensional and are designed by experts in the discipline.

In a recent interview with CPC/BIM, Watt shared his thoughts on BIM and where he sees it going in the future. He also revealed the unique approach his company is taking in developing software specifically for estimating in BIM.        

Watt believes that the end user and the current work processes must be taken into account when developing software for use in the BIM environment. "The software should be designed based on the user and the way that particular user performs their tasks." 

My first thought was that this is Product Development 101; however, after closer review, it appears that not all software vendors follow this principle. It is important to keep in mind that estimators may be part of the design, construction, or owner team, and as such the cost-estimating tasks have a different purpose. Each estimator has a particular objective for his or her estimate, but in the end the goal of all estimators is to have confidence that the estimate is accurate. To ensure the estimator's needs are met, WinEst integrates the professional estimator into the product development through an iterative process of testing and feedback by the end user. The company used this approach in its design and development of the two BIM solutions offered for cost estimating -- DesignEst Pro and ITO. The two products are different in their application as each is better suited for a particular approach to cost estimating depending on the sector in which the estimator works.  

DesignEst Pro is an add-on to the ProPlus software and offers the estimator a powerful tool for generating a complete cost estimate using WinEst. DesignEst Pro provides the BIM team with an opportunity to mine data from the design model (3-D) for the 4-D (time) and 5-D (cost) models. DesignEst Pro spans the multiple dimensions using an application programming interface for the transfer of data. On the front end, DesignEst Pro maps the components from a 3-D Revit model to the estimate database. From that point, DesignEst Pro can then integrate the data into Primavera Enterprise or Microsoft Project. It is important to point out that the functionality of DesignEst Pro works only as an integrated solution. Therefore, Revit must be installed on the same system as DesignEst Pro to transfer data for cost estimating. Primavera or Project must also be installed on the same system to transfer data for scheduling. DesignEst Pro is ideal for the architecture firm generating budgets in-house because of its seamless transfer between the design model and estimate. You literally push a button -- "Translate" -- to generate the price-loaded estimate from the Revit model. Figure 1 is an image of the automatic estimating function in DesignEst Pro. 

DesignEst Pro is an application that also works well for a design-build or integrated project delivery team in which the protocol exists to support discipline-specific processes and accepted practices across the team members' roles and tasks on a project. Estimators are confident with the estimates generated in these scenarios using DesignEst Pro. However, the reality is that cost estimates go beyond the architect's budget and that project teams are not always integrated or have protocol to generate a model that estimators deem reliable.      

The second WinEst BIM product, ITO, is in development and is being designed with the general contractor and subcontractor estimator in mind. Estimators on the construction side of a project focus on accurate estimates as the basis of project profit. With ITO, there is no need for the estimator to own a copy of Revit to extract quantity takeoff data from a design model. Instead of translating the quantity takeoff data from the design model to the estimating software, as is done with DesignEst Pro, ITO uses a .dwf to display the model from which the estimator can complete the takeoff. The only thing needed by the estimator is ITO and the .dwf viewer to open the file. The estimator performs the takeoff on the screen, and the data generated from the takeoff is then loaded into the cost estimating software of choice. 

As shown in Figure 2, the estimator has the quantity takeoff data prominently displayed in the ITO screen. ITO is designed with the general contractor and subcontractor in mind and focuses on the relevant task at hand -- cost estimating. ITO is planned for release in the third quarter of this year. ITO is in the demonstration phase, and Watt is traveling around the U.S., requesting feedback from estimators about the product. This is a critical element in the WinEst philosophy and approach to the development of ITO. 

Estimators must be confident in the data generated by the quantity takeoff in BIM if they are to use the data for budgeting and cost-estimating purposes. DesignEst Pro provides this confidence for cost estimators in an integrated team environment with established protocol. ITO provides this confidence for cost estimators in a construction model environment focused on the construction process. 

For more information, visit the company's website at www.winest.com.

References

McGraw-Hill Construction, SmartMarket Report, 2009, "The Business Value of BIM," retrieved Oct. 15, 2009, from http://bim.construction.com/research/FreeReport/default.asp.