Connection: BIM, Spec, Estimate

Have you made the connection yourself? Connecting data to make it available and useable for each team will improve efficiency and reduce risk for every construction project. The focus has been on inserting data into BIM to describe the objects the design team includes in the model. A door? Oh yes, of course the model builder knows it is a solid core, plain sawn, mahogany veneer, transparent finished door in a matching wood frame when the object is dropped into the model during SD phase. Get real!

The team will know it is a door. Because it is a door, it will have a frame. At SD, who cares what the materials are? It will likely be a generic size: 3'-0" x 7'-0" until the refined model layout dictates otherwise. The team does know it is an interior door. For now that is all that matters.

Q: What data must the model contain?

A: Enough data to identify the object as an interior door.

The interior door can be described elsewhere in more detail, as the design develop and the detail is decided. There is no need to slow the model development to enter product and material decisions that are likely unknown. Keep the model object generic at the start.

Enter UniFormat

UniFormat is an amazing organizational tool. It is a companion to MasterFormat, the standard format for construction specifications. Both formats are designed to look at a construction project from two different vantage points, with a different set of filters, if you will.  UniFormat is organized by systems and assemblies. Whereas MasterFormat is organized by work results. BIM objects are systems and assemblies. The door object includes the door, the frame, and the door hardware required to hang the door in the frame.

UniFormat was created by estimators and embraced by specifiers to create preliminary project descriptions (PPD). In fact, CSI publishes PPDFormat, a document that explains how to use UniFormat to create PPDs. UniFormat provides the key to linking BIM, Spec, and Estimate. Imagine that - the three sets of data controlling a construction project all logically linked and coordinated as a consequence.

Because UniFormat's organization is systems and assemblies, it can be used to identify BIM objects. That interior door? C1030!

  • C for Interiors
  • C10 for Interior Construction
  • C1030 for Interior Doors

Select the BIM door object. In Revit, open the family properties window. Check the Assembly Code and if C1030 is not there, just insert it. Then when the model is queried through schedules, the model will show it contains interior doors. Share the model, and then the specifier and estimator will know interior doors exist.

With this basic information, the specifier can after discussion with the design team, describe the door performance, quality, and construction to suit the project - documented in a PPD. The total information for the interior doors will be a single page of printed text. (Conspectus Sample PPD) The estimator, now, in addition to quantity, knows the quality that must be priced to accurately determine the project cost. No guessing. No misunderstanding. The basis of the design and the basis for the estimate are both defined by the same document.

When analyzing the costs to massage the price, the analysis will be based on fact, not assumptions. Additionally, costs can be evaluated against potential effect on performance and quality. If the costs must be adjusted (hey, it's possible the cost may be too low), agree what changes to the basis of design must be made. Modify the PPD to document the change, and then determine the new cost.

Imagine: BIM, Spec, and Estimate linked and working together to ensure the project meets the owner's requirements within the owner's budget. No VE required. No frantic redesign. Improved profit margins for all. Utopia!

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