Rich Creveling, Senior Estimator for Swinerton Builders, has vast experience as a VDC Coordinator and BIM consultant.
Building Information Models are rich datasets that can be used in the process of creating estimates. Understanding how to use UniFormat and MasterFormat in a project integrating model-based estimate is often the first step in transitioning from exclusively 2D based inventories and quantities.
UniFormat and MasterFormat are published organizational standards used in North American building Design and Construction. The two standards are fundamentally different in their intent. UniFormat is a systems-based organization of building content. MasterFormat is a material-based organization of building content.
Concrete is a very common building material. In MasterFormat, a value of 03-31-00 is reserved for Concrete Material. All use of concrete will be specified with this value of 03-31-00. However, concrete material is used in the construction of many building systems. UniFormat can be used to differentiate the many places concrete is used in a building. Examples of UniFormat codes that can identify how concrete is being used in a project are as follows:
- A1010 Foundations
- A1020 Special Foundations (Caissons and Drilled Piers)
- A1030 Slab on Grade
- A2020 Foundations
- B1010 Structure
- C2010 Stairs
- G2030 Site Improvements
Within the various systems above there will typically exist additional MasterFormat material specification codes such as:
- 03-11-00 Formwork
- 03-21-00 Concrete Reinforcing
- 07-11-00 Damp Proofing
- 31-23-00 Excavation and Backfill
The materials above typically work in conjunction with one another as a “system”. The materials can be organized together with UniFormat. This groups the materials together instead of distanced from one another. Grouped together the materials may be thought of as a “Work Package” or “Assembly”.
During design, if a decision is being weighed to use Standard Foundations or Drilled Piers the decision is being weighed as follows:
1. A1010 Spread Footings
a) 03-11-00 Formwork
b) 03-21-00 Concrete Reinforcing
c) 03-31-00 Concrete Material
d) 05-12-00 Anchor Bolts and Embeds
e) 31-23-00 Excavation and Backfill
2. A1020 Drilled Piers
a) 03-21-00 Concrete Reinforcing
b) 03-31-00 Concrete Materials
c) 05-12-00 Anchor bolts and Embeds
d) 31-23-00 Excavation and Backfill
The design decision is really being made at the “System” level and not the “Material” level. The material values will exist as an outcome of a decision made at the systems level. The modeling of this content will also be executed at the “Systems” level in that Elements will be selected and placed as Systems and not as individual Materials.
In fact, Building Information Modeling has provided the impetus for a dramatic increase in the utilization of UniFormat coding in both design and construction as it is essentially more congruent with decision making and execution of modeling.
MasterFormat has been historically, and is presently, more prevalent in the Construction Industry as Material coding is more congruent with the transactions managed and work executed to construct a design. As previously illustrated, a design decision will be made between Spread Footings (A1010) and Drilled Piers (A1020). However, in either case a contractor will typically need to transact with subcontractors and suppliers separately to procure Concrete Reinforcing (03-21-00) and Concrete Material (03-31-00).
Without the use of UniFormat a building professional may endeavor to generalize these systems as “Division 03” (like 03-00-00). A more dramatic example of how this generalization falters is “Brick Veneer on Metal Stud Exterior Wall”. This system and its materials could be organized as:
3. B2010 Brick Veneer on Metal Stud Wall
a) 04-21-00 Clay Unit Masonry
b) 09-29-00 Densglass Sheathing
c) 05-41-00 Structural Studs
d) 07-21-00 Bat Insulation
e) 09-29-00 Rated Gypsum Board
An attempt to rationalize this particular building system with the more familiar MasterFormat might endeavor to label this element as consistent with 04 Masonry. However, a review of the materials in this system reveals that it is difficult to consider this as belonging to any of the Material Divisions because it contains many and they are all integral in the system.
Furthermore, from a standpoint of Best Practices in Building Information Modeling, it is not practical or efficient to model these components separately so that a material coding could be more comfortably assigned. This is significantly affected by the placement of doors and windows in a wall. Doors and windows can only reside within a single Wall element. It is important that the door or window penetrate through the entire cross section of the wall. Placing the entire cross section of a wall as outlined above is, to a great extent, the most appropriate way to accomplish this.
In summary, UniFormat as a coding scheme is more closely aligned with the nature of composite elements in a Building Information Model than MasterFormat. BIM authoring tools provide more opportunity to assign UniFormat coding than MasterFormat coding. Analyzing a project with UniFormat coding is also more closely aligned with the design decision making process. Interpreting a project with respect to “systems” using UniFormat increases the velocity and accuracy of iterative design decisions, resulting in a better building design for the owner and improved constructability in the field.