Who Creates As-Built Drawings? Roles and Responsibilities
The responsibility for creating as-built drawings depends on the project phase and what type of as-built documentation is needed. Multiple parties may be involved, each with distinct responsibilities.
During New Construction: The Contractor's Role
During active construction, the general contractor is typically responsible for:
- Maintaining redline markups on the original construction documents throughout the build process
- Tracking field changes — moved walls, rerouted utilities, dimension modifications, material substitutions
- Coordinating subcontractor input — each trade (mechanical, electrical, plumbing, structural) provides redline markups for their scope of work
- Submitting final redlines to the architect at project closeout
However, there is a well-known accuracy problem with this approach. Contractors are focused on building, not documenting. Studies show that contractor redlines miss 30-40% of field changes, particularly:
- MEP routing behind walls and above ceilings
- Minor dimensional changes (a wall moved 2 inches)
- Underground utility modifications
- Last-minute field adjustments made by individual tradespeople
The Architect's Role
The architect of record is typically responsible for:
- Incorporating contractor redlines into the final record drawing set
- Reviewing and stamping the final documents
- Delivering the completed record drawings to the owner as part of project closeout
Some contracts place the full responsibility on the contractor to produce final as-built drawings (not just redlines), but this varies by contract language and project type.
Subcontractor Responsibilities
Each subcontractor is generally responsible for providing redline markups of their specific scope:
- Mechanical contractor: HVAC ductwork, equipment locations, pipe routing
- Electrical contractor: Conduit routing, panel locations, circuit assignments
- Plumbing contractor: Pipe routing, fixture locations, connection points
- Structural contractor: Steel connections, modifications to structural members
- Fire protection: Sprinkler routing, riser locations, valve positions
The quality of these markups varies dramatically. Some subcontractors maintain meticulous records; others provide minimal or no redline documentation.
For Existing Buildings: The Scanning Firm's Role
When as-built documentation is needed for existing buildings — whether for renovation planning, facility management, insurance, or legal purposes — the work is typically performed by:
- 3D scanning firms (like THE FUTURE 3D) that use laser scanners and mobile mapping systems to capture precise, comprehensive measurements of existing conditions
- Land surveyors who use total stations and other survey instruments for targeted measurements
- Drafting/CAD technicians who convert field measurements into formal drawing sets
3D scanning has become the preferred method for existing building documentation because it:
- Captures every visible surface (nothing missed)
- Achieves ±1-6mm accuracy (far exceeding manual measurement)
- Creates a reusable point cloud that can be re-measured remotely
- Produces BIM-conversion-ready data in standard formats (E57, RCP, LAS)
The Property Owner's Responsibility
Ultimately, the property owner is responsible for:
- Ensuring as-built documentation exists and is maintained
- Hiring qualified firms to create as-built drawings when needed
- Updating documentation after renovations, tenant improvements, or system modifications
- Storing and organizing as-built records for future access
The Accuracy Problem — and the Solution
The fundamental challenge with traditional as-built documentation is that it relies on human diligence at every step. When a contractor forgets to mark up a change, when a subcontractor provides incomplete redlines, when field modifications happen on a Friday afternoon and nobody writes them down — the as-built record becomes incomplete.
3D laser scanning solves this problem by removing human memory from the equation. The scanner captures everything visible, regardless of whether anyone remembered to document a change. This is why scanning-based as-built documentation is considered the most reliable method available.
THE FUTURE 3D provides professional as-built documentation services using Trimble X12, NavVis VLX3, and other survey-grade scanning equipment. Get a quote for your project.