In construction, CD stands for Construction Documents, the detailed set of drawings and specifications that contractors use to price and build a project. It’s the phase where a building’s design gets translated into precise, buildable instructions, covering everything from exact dimensions and materials to structural details and mechanical systems. Of all the phases in a building project, the CD phase demands the most time and the largest share of the architect’s fee.
Where CDs Fit in the Design Process
A building project moves through a series of design phases before anyone breaks ground. The standard sequence looks like this:
- Schematic Design (SD): broad concepts, basic layouts, overall direction
- Design Development (DD): refined plans with coordinated systems and material selections
- Construction Documents (CD): fully detailed drawings and specifications ready for bidding and building
- Bidding: contractors review the CDs and submit pricing
- Construction Administration (CA): the architect monitors the build and answers questions
The CD phase begins after the owner formally approves the design development documents. At that point, the architect and engineering team shift from refining the design intent to producing a complete technical package. Think of DD as agreeing on what the building will be, and CDs as spelling out exactly how to build it.
What a CD Set Includes
A full construction document package has two major components: the drawings and the project manual.
Drawings
The drawing set is organized by discipline, with each discipline getting its own prefix on every sheet. Architectural sheets (A) cover floor plans, elevations, sections, and finish details. Structural sheets (S) show foundations, framing, and load paths. Civil sheets (C) address site grading, drainage, and utilities. Then there are separate sheets for mechanical (M), electrical (E), and plumbing (P) systems. A mid-size commercial project can easily have hundreds of individual sheets.
Every drawing includes precise dimensions, material callouts, cross-references to related details, and notes explaining exactly what the contractor needs to do. The level of detail jumps significantly from the DD phase. Where a DD floor plan might show wall locations and general room sizes, a CD floor plan specifies wall thicknesses, door and window types by schedule number, finish materials for every surface, and exact dimensions to fractions of an inch.
Project Manual and Specifications
The project manual sits alongside the drawings and contains written requirements that don’t fit neatly on a drawing sheet. The specifications describe materials, quality standards, and installation methods in detail. For example, a specification section for concrete might define the mix design, curing requirements, surface finish expectations, and testing protocols.
The project manual also typically includes bidding requirements, instructions to bidders, general conditions of the contract, and forms that govern how the project will be delivered and documented. Together, the drawings and the project manual form the complete construction document set.
How Contractors Use CDs
The CD set is what contractors work from when they estimate costs and submit competitive bids. Every subcontractor, whether they handle steel, drywall, or HVAC, pulls their scope of work from the relevant sheets and specification sections. The more complete and coordinated the documents are, the fewer assumptions a contractor has to make, which means tighter and more accurate pricing.
During construction, the CD set becomes the legal reference for what the contractor is obligated to build. If a dispute arises about materials or methods, the drawings and specifications are what everyone points to. Field crews use printed or digital copies of the CDs daily to lay out walls, route ductwork, place reinforcing steel, and verify dimensions.
CDs and Building Permits
Local building departments require a construction document set before they’ll issue a permit. Reviewers check the drawings for code compliance, structural adequacy, energy performance, fire safety, and proper site layout. Typical permit submissions need to show site plans with setback distances, floor plans with complete dimensions, structural calculations, energy compliance certificates, and details about water, sewer, and fire protection connections.
A licensed architect or engineer must sign and stamp the documents, taking professional responsibility for their accuracy. If the building department finds issues during plan review, the architect revises the CDs and resubmits. No permit gets issued until the documents satisfy all applicable codes and ordinances.
Time and Cost of the CD Phase
The CD phase is the most resource-intensive part of design. A common fee breakdown allocates about 15% of the architect’s total fee to schematic design, 20% to design development, and 40% to construction documents. The remaining 25% covers bidding and construction administration. That 40% figure reflects the sheer volume of detailed drawings and coordination required.
Timeline varies by project size and complexity. A small renovation might need a few weeks for CDs, while a large institutional or commercial building could spend six months or more in this phase. The time is driven largely by coordination: making sure the structural engineer’s beams don’t collide with the mechanical engineer’s ductwork, that the plumbing routes work with the architectural layout, and that every detail across dozens of sheets agrees with every other detail.
Quality Control During CD Production
Because so many disciplines contribute to a single CD set, coordination errors are a constant risk. A structural column that shows up on the engineer’s drawings but lands in the middle of a corridor on the architect’s plan is the kind of conflict that costs real money if it’s caught during construction instead of on paper.
Design teams run internal quality control reviews at key milestones, typically at 50%, 90%, and 100% completion of the documents. Reviewers check for technical accuracy, code compliance, interdisciplinary coordination, and consistency between drawings and specifications. Checklists cover every discipline: architectural, structural, civil, mechanical, electrical, fire protection, and cost estimating. Building information modeling (BIM) software has made clash detection faster by flagging physical conflicts between systems automatically, but human review still catches the errors that software can’t, like a specification that contradicts a drawing note.
The goal is a set of documents complete enough that the contractor can build from them without constant clarification requests. In practice, questions always come up during construction, but a well-coordinated CD set minimizes them significantly.