PPD: Deliverable Document and Powerful Design Tool

What do you use to describe your design projects? Will owners, lenders, estimators and others understand the design intent? Traditional methods rely on design narratives and outline specs to supplement drawings. Each design team develops their own method for presenting the written information. As a result, sharing the information among various teams and building a library of design descriptions for use with future work is difficult.

Louis Medcalf, FCSI, CCS and Chair of the CSI PPDFormat Task Team explained to the CSI Specifying Practice Group how Preliminary Project Descriptions (PPD) can simplify collecting and sharing information for the benefit of current and future project teams.

The CSI Specifying Practice Group meets the first Thursday each month. Everyone that reads or writes specifications is welcome to join the group and share ideas.

PPDs are not widely known nor widely used even though the concept first appeared in the CSI Manual of Practice in 1989. CSI created the PPD Task Team in 2009 to write a new publication to describe how to prepare PPDs. As a result, PPDFormat was published in May 2010 and is available from CSI. Now the industry has a guideline to help structure PPDs and the information they contain.

The PPD structure provides a systematic checklist to help ensure all the appropriate subjects are discussed. The checklist is UniFormat, the construction classification system for building systems and assemblies. UniFormat was designed for cost estimating. So, PPDs are coordinated with published cost estimating systems, allowing parallel presentation of design data and cost data.

The PPD structure allows each system and assembly to be discussed by description, function, and component. This structure enables analysis and effective comparison of various building systems used to perform the same function. Multiple solutions may be presented as potential design options without the need to show each system graphically. This approach allows options to be analyzed for aesthetics, life-cycle costs, durability, and other factors without investing significant time to document each option.

Documenting all information in a building model is not practical. PPDs provide the opportunity to describe what is required for each assembly that is represented by a model object without inserting the data into the model. Model the major building elements and rely on PPDs to describe the secondary and accessory components that complete the major assembly.

PPDs are useful at every project design phase. They can serve as the Schematic Design project report, the Design Development outline spec, and the Construction Documents quality control tool. They can record the decisions, the rationale, and the design at each step during the process. PPDs are a valuable resource throughout all stages of the design process.

Read the meeting notes and view the PowerPoint presentation slides at the CSI Blog.

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