Specifications provide the basis for design and installation of mechanical insulation.
The construction industry commonly uses a MasterFormat specification that is modified for each project with up-to-date products and conditions. A limitation with this approach lies in the fact that detailed project information contained within the MasterFormat specification is not readily accessible or sometimes even available early on in the project design phase. With no project information available during the primary project description phase, the detailed MasterFormat specification that is produced may need considerable editing to accurately capture the goals of the project.
If a project is delivered by construction management (CM), or by an owner-builder, a big part of the CM’s or the owner-builder’s mandate is to look for equivalents that are less expensive, easier, or faster to construct—also known as value engineering. The precision of the MasterFormat specification may limit the creativity that the CM or owner-builder can bring to the value engineering process, leading to less than optimal results. Further, any changes have to undergo careful review by the specification writer and the designers to ensure that the performance requirements are met.
An alternative is to organize performance specifications by UniFormat instead of MasterFormat. The ASTM E1557 2010, Uniformat II standard is another way of looking at the project and its definitions. The Uniformat system is a top down project definition system that can work in conjunction with the MasterFormat specification system. The Uniformat system defines assemblies through performance and other user defined variables, starting at a concept level then progressively refines the project deliverables. Specific products are only an end result.
With UniFormat specifications almost all selections of proprietary materials and equipment can be left to the constructor, who selects them on the basis of detailed descriptions of performance attribute requirements.
This method provides more flexibility in meeting performance objectives and may result in cost savings to the owner. The method is ideal for projects where design goals can be easily described in written form.
The UniFormat II document structure can also be used for Preliminary Project Descriptions. Both performance specifications and Preliminary Project Descriptions share a similar approach, they differ in purpose and level of detail. Preliminary Project Descriptions are not suitable as contract documents because descriptions of elements and their components are brief and intended only for conveying preliminary information to evaluate the practicality of the design. Performance specifications must have sufficient detail to be suitable for use as contract documents, including actual cost of the work.
The basic underlying ideas behind the concept of the Preliminary Project Description are:
- Written descriptions of the Schematic Design should be organized around systems and assemblies that correlate to prevailing industry methods of cost estimating for this phase.
- Written descriptions should allow design professionals to provide sufficient information for cost estimating without the necessity of making final design decisions.
- Written descriptions should document qualitative requirements for the project appropriate to the level of decision-making and detail in the design.
- Using an industry-standard organizational format provides a checklist to help design teams make sure all appropriate subjects are included.
Further, as the industry moves into using Building Information Modelling  (BIM) for producing construction documentation, designers should correlate the organization of information into functional elements in the Preliminary Project Description, which should correspond to the model objects in BIM or conventional CAD software. The major developers of BIM software use UniFormat as the organizing format for objects in the electronic model. By aligning the descriptions with objects in the electronic model, designers can achieve a unified presentation of the design not possible with un-structured narratives.
For purposes of this study, we have provided a simple UniFormat model project description as an example. Note that most elements will have multiple components. In these cases, it is necessary to describe requisites for the entire assembly as well as for the constituent parts.
In Section 3 of this Guide, detailed reference specifications are provided using MasterFormat, and a numbering matrix for MasterFormat and UniFormat is provided. Either or both formats may be used for a given project, depending on project needs.
 Building information modeling (BIM) involves the generation and management of digital models of physical and functional characteristics of a facility, including visualization, coordination of construction documents, and other information.