Vipsit reviews design rationales that are voluntary documents developed early in the design phase aimed at documenting the design intent in short, sharp write-ups that explains the rationales for why the building is constructed the way it is and functions as it does. The design rationale will help document what the building can do, and what it cannot do.

Capturing the “WHYs”

This document will, at the end of the construction phase, be one of most important documents created and one of the very few documents that will transfer over and remain an active useful document for the end users in the years to come.

The document will grow throughout the design process, capturing the rationales behind some of the design decisions chosen. It will, at the end of the construction and commissioning phase, be the historic mark in time that will help future generations understand the facility and its current capability. The document will capture the design decisions that are the basis for the facility, what agents and procedures can be safely handled in the facility, and what cannot immediately be done without additional, thorough risk assessments, evaluations and possibly even adjustments.

Often these design rationales will have enclosed, simplified versions of some of the design and construction drawings that can, in a one-page view, explain features of the facility.


The document facilitates the future dialogue with certifying bodies and inspectors. The discussions and explanations become more solid and tangible when the design philosophy is clearly outlined and explained especially if conflicting guidelines have had to be sorted out.


Using a design rationale document, including the explanatory drawings and protocol maps, makes the SOP’s more understandable and the risk assessment discussions clearer and sharper.


The right time to capture the design choices on a list is throughout the design phase and especially during the value engineering process. This is the point where the facility path derails from what the scientists thought they had asked for. The value engineering process is where the budget inspired compromises are made and where some of the original “wants” begin to disappear from the project.

The right time to create the supporting drawings and figures is close to the end of the design phase. At that time it is easy to create an additional CAD layer that will illustrate a specific message for an SOP or be the base for the protocol mapping figures and flows. Later it will take more effort to scan drawings and try to create the message with arrows and colors in PowerPoint, resulting in a less professional looking final product. The design team is still on the project, and have the professional tools to create these visuals.


Unfortunately, it is rare in these types of projects that anybody has the bandwidth to add this to the long task lists of aspects that need to be addressed. In the late design phase everybody is in survival mode, wearing several hats and has done that for a long time and nobody has energy or inspiration to chime in with a creative mindset and “invent” more tasks to do. The bandwidth is simply not there. A template can be a way to kickstart the process and make it more manageable.