As the phrase implies, model-based estimating means using the modeled elements and their derived construction-caliber quantities as an important part of a cost plan. Other popular terms include BIM-based estimating and 5D BIM.
Many GCs already have a database of estimating information, so linking the model elements and quantities to this information is quite easy. In Vico Office, for example, we've built an Excel Import feature that allows the estimator to bring in work done in Timberline, MC2, and RIB to our open 5D BIM platform. Now this expertise from the estimating department can be linked and used with any BIM model for almost instantaneous cost plans.
Now, let's be clear. There is no easy-button that you press to get model-based estimates for every project every time. The model must be constructed appropriately to be useful in deriving quantities, but model-based estimating is a reality. Firms are migrating away from paper-based estimating systems and adopting model-based cost planning as a way gain competitive advantage.
Caption: Sifting through mounds of data, papers, and files, is not a lean construction technique. Repurposing all the estimating department expertise into a knowledge base of cost and time elements makes it easily accessible for any BIM model.
Construction estimating software must be able to straddle the model-based cost planning techniques with the traditional estimating techniques in order to be successful with Estimators. We address this gap specifically with:
>> Manual takeoff items (in addition to the derived quantities from the BIM)
>> Manipulation of quantity calculations in the Formula Editor
>> Mining past projects completed in Timberline with the Excel Import
>> Gradually evolving the specificity of the cost plan in accordance to the model progression specification
>> Creating multiple versions time-stamped cost plans that can easily be compared for difference
>> Being able to ask questions of the project team using the model, such as "what happens if we change ...?"
Here are some resources for you and your team to help you determine if model-based estimating is the next step in your BIM roadmap:
Webinar: Model-Based Estimating
Blog: The Flying Dutchman's Blog on Construction Cost Planning
Services: Construction Services for Cost Planning
We also offer a step-by-step guide to our 5D virtual construction workflow with video tutorials. These videos are just 2-5 minutes in length, but illustrate how to use a particular piece of functionality. You can access the video library index and view just what you need, or download the complete set of training videos.