(Editor's note: This quick look at Target Value Design, which is a form of model-based estimating, is the latest in a series of blog posts about CAD and BIM software that comes to us from AECbytes.com.)

The concept behind Target Value Design (TVD) or Target costing is simple: budget first, then design. The aim of Target Value Design is to keep costs within the originally discussed price by setting up a cost estimate first and then designing the project based on that estimate. Rapid cost feedback to the design team plays a huge role in TVD; by extracting quantities from the virtual model and model-based estimates one can quickly achieve this goal. Model-based estimating is one of many BIM tools that allows for Target Value Design.

In creating a Target Cost process, cost needs to be an input within the design process. There are numerous approaches to this goal; the organizational approach, which brings a group of teams together to provide rapid cost feedback, is just one of those approaches.  Another process, cost estimating based on a BIM, was engineered at Stanford University’s Center for Integrated Facility Engineering in early 2000.

Model-based estimating involves integrating the object attributes from the designer’s 3-D model along with cost information from the estimator’s database. This method has proved to be much more efficient in comparison to the 2-D drawing-based estimating, as it is not only quicker but also eliminates the possibility of errors and omissions.

Regardless of the recent hype around BIM and cost estimating, there are very few implementations on larger projects. For those examples that are available, check out Model-based estimating to inform Target Value Design at AECbytes.com.