Design Documentation, BOM/LOM & QA

Design Documentation, BOM/LOM & QA

The Design Documentation Package

A complete RCDD design package is more than a set of drawings - it is the instrument that lets an installer bid accurately, a contractor build correctly, and an AHJ inspect against a known standard. Three components make up the core package:

• Drawings: floor plans showing pathway routing, space locations (TR/ER/EF), outlet/device locations, riser/single-line diagrams showing the backbone hierarchy, and detail sheets such as rack elevations, firestop assemblies, and grounding busbar layouts.
• Specifications: the written technical requirements - referenced standards (TIA/ISO/NEC/local code), product performance requirements (category, fiber grade, cable listing), installation workmanship requirements, and testing/acceptance criteria.
• Calculations: the supporting math behind the drawings - pathway and conduit-fill calculations, cable-count and cross-connect sizing, fiber loss-budget calculations, space sizing/power/cooling load estimates, and horizontal/backbone distance verification against the limits covered earlier in this chapter.

These three pieces must agree with each other; a drawing that shows a run the calculations do not support, or a spec that references a standard the drawings do not follow, is exactly the kind of internal inconsistency a QA review exists to catch before it reaches a contractor.

Bill of Materials / List of Materials (BOM/LOM)

The Bill of Materials (also called a List of Materials, LOM) is the itemized quantity take-off tied directly to the drawings: cable by type and length, connecting hardware, patch panels, racks/cabinets, faceplates and outlets, pathway/support hardware, firestop materials, grounding/bonding hardware, and labor estimates. It serves three audiences at once - the estimator pricing the job, the contractor procuring materials against the design intent, and the owner tracking budget against scope. A BOM that is out of sync with the drawing set - a missing device type, wrong cable category, uncounted spare capacity - is a direct path to change orders once construction starts, so BOM accuracy is a concrete, checkable deliverable of the design phase, not an afterthought generated at the end.

QA Evaluation

Before a design package is released for bid or construction, it goes through a QA evaluation - the RCDD's own internal review, independent of the owner's approval loop. QA checks for: compliance with the applicable codes, standards, and the project's written scope of work; internal consistency between drawings, specs, and calculations; and coordination conflicts with other trades - electrical (panel/conduit clashes, power availability at telecom spaces), mechanical (HVAC ductwork through a TR ceiling space, floor loading), and structural (penetrations, sleeve locations). Catching a clash on paper during QA is dramatically cheaper than catching it in the field after cable has already been pulled. A practical QA checklist also verifies that the labeling/administration scheme is applied consistently across every drawing sheet, that accessibility clearances at racks and telecom spaces are respected, and that grounding/bonding continuity shown on the drawings actually closes the loop back to the building's grounding electrode system - gaps in any of these are common, low-visibility errors that a fresh set of eyes catches far more reliably than the original designer re-reading their own work.

Owner Review & Approval Loop

Design documentation is delivered in progressive milestone sets - commonly 30%, 60%, 90%, and 100% (or issued-for-construction) - rather than as a single final package. At each milestone:

1. The RCDD issues the current design set to the owner and other stakeholders (architect, MEP engineers, IT).
2. Reviewers return comments and redlines.
3. The RCDD incorporates the feedback and documents how each comment was resolved.
4. The owner formally signs off on that milestone set.

Formal sign-off - not just informal verbal agreement - is what authorizes the RCDD to proceed to the next, more detailed design stage; skipping this loop, or proceeding on unresolved comments, is a common source of late-stage scope disputes and rework.

Document Control & Closeout

Every design set needs version control: a drawing issue log that tracks revision number, date, and the reason for each change, so field personnel are never working from an outdated sheet. As the project moves from design into construction, the RCDD's documentation role does not stop - submittal review, field observation against the issued-for-construction set, and punch-list generation all trace back to the same drawings, specs, and calculations produced during design. At closeout, the design package is updated into record (as-built) documentation reflecting what was actually installed, including any field-approved deviations, and is handed to the owner along with test result records and warranty documentation - the administration and labeling scheme covered earlier in this guide is what makes that closeout package usable years later rather than an unreadable pile of paper.

Design Takeaway

Documentation, the BOM, QA, and the approval loop are not paperwork bolted onto the technical design work of earlier chapters - they are the process domain that turns a technically correct design into a fundable, buildable, ownable project, and they are exactly where the RCDD exam's Support Bid/Tender, Support Installation, and Define Scope tasks live.