RCx documentation status?

• A. RCx is identical to design-build
• B. RCx ignores performance
• C. RCx projects often have limited documents; focus on performance improvements.
• D. RCx always has full design documents

Answer: (C)

In RCx, the emphasis is on optimizing how an existing building operates rather than creating new designs from scratch. Because you’re starting with as-built systems and control sequences that were installed and tuned in the past, many projects don’t have a complete set of current design documents. The focus is on identifying performance gaps, proposing practical, low-risk improvements, implementing them, and then verifying that those changes actually improve the building’s operation through measurements and post-implementation data.

That means the documentation you typically see is pragmatic and targeted: a record of current problems, proposed remedies, field changes, verification tests, and the resulting performance data. You’ll usually rely on whatever baseline drawings, equipment lists, and control logic exist, but you’re not building a full, new design package. The aim is to capture enough information to show that the performance improvements were achieved and to sustain those gains, not to produce comprehensive design documentation for a new project.

This isn’t identical to design-build, where a new design package is developed and handed over before construction. RCx actively uses and tests existing systems to improve performance, rather than generating complete design documents for new construction.