As-Built Drawings: The Complete Guide

As-built drawings are revised construction documents that reflect the actual, physical conditions of a building or structure after construction is complete. Unlike design drawings, which show the architect's or engineer's original intent, as-built drawings capture every change, deviation, and modification that occurred during construction, providing a true record of what was actually built.

These drawings are sometimes called "record drawings" or "red-line drawings" (referring to the traditional practice of marking changes in red ink on the original blueprints). They serve as the authoritative reference for the building's actual configuration and are essential for facility management, future renovations, regulatory compliance, and real estate transactions.

When Are As-Built Drawings Needed?

As-built drawings are required or strongly recommended in these situations:

• Building permit closeout: Most jurisdictions require as-built drawings before issuing a certificate of occupancy
• Renovation and retrofit projects: Accurate existing conditions are essential for design coordination
• Facility management: Space planning, maintenance routing, and asset tracking rely on current documentation
• Real estate transactions: Due diligence requires verified building documentation
• Insurance claims: Accurate square footage and building configuration data support claims
• LEED and green building certification: Energy modeling and compliance verification require as-built data
• Tenant improvements: Landlords and tenants need accurate base building documentation for build-outs

A complete set of as-built drawings includes multiple drawing types, each documenting different aspects of the building. The specific types required depend on the project scope and intended use.

Understanding the distinction between as-built drawings and design drawings is fundamental for anyone working in construction, architecture, or facility management. While they may look similar, they serve very different purposes and reflect very different realities.

Creating as-built drawings has traditionally relied on manual measurement. Today, 3D laser scanning offers a faster, more accurate, and more complete alternative. Understanding both methods helps you choose the right approach for your project.

Traditional Manual Measurement

The traditional as-built survey process involves a drafting team entering the building with tape measures, laser distance meters, and graph paper. They manually measure each room, corridor, and space, sketching layouts and recording dimensions. These field notes are then translated into CAD drawings back in the office.

Limitations of the traditional approach:

• Time-intensive: Measuring a 50,000 SF building can take 1-3 weeks of field work
• Accuracy limitations: Manual measurements typically achieve 0.5-1 inch (12-25mm) accuracy
• Incomplete data: Surveyors measure selectively, missing details between measurement points
• Human error: Transposition mistakes, misread measurements, and missed areas are common
• No point cloud: Once field work is done, there is no way to re-check measurements without returning to the site
• Above-ceiling challenges: Measuring MEP systems above ceilings is extremely labor-intensive

3D Laser Scanning (Modern Approach)

3D laser scanning uses LiDAR technology to capture millions of precise measurements per second, creating a comprehensive 3D point cloud of the building. This point cloud becomes the foundation for producing highly accurate as-built drawings.

Advantages of the scanning approach:

• Speed: The same 50,000 SF building can be scanned in 1-3 days
• Accuracy: Survey-grade precision of 1-4mm with professional scanners
• Completeness: Every visible surface is captured, not just selected measurements
• Verifiable: The point cloud provides a permanent, re-measurable record of the space
• Remote work: Drawings can be produced from the point cloud without additional site visits
• Future-proof: Point cloud data can be used for BIM modeling, 3D visualization, and other applications

The process of creating as-built drawings from 3D laser scanning follows a structured workflow that combines advanced scanning technology with professional drafting expertise. Here is the step-by-step process using equipment like the Trimble X12, NavVis VLX 3, and FARO Focus Premium.

As-built drawing projects produce multiple deliverable types in various formats. Understanding these formats helps you specify exactly what you need and ensures compatibility with your design and facility management software.

Drawing Formats

Point Cloud Formats

When 3D laser scanning is used, the point cloud data itself is a valuable deliverable:

As-built drawings are governed by various industry standards and regulatory requirements. Understanding these standards helps specify the right deliverables and ensures compliance for your project type.

AIA Document E202 (BIM Protocol Exhibit)

The American Institute of Architects' E202 establishes protocols for BIM-based projects, including Level of Development (LOD) standards for as-built BIM models. LOD 500 specifically addresses field-verified as-built conditions, requiring that model elements have been verified against actual constructed conditions.

ASHRAE Standards

ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) standards reference as-built documentation requirements for HVAC system documentation. Accurate as-built MEP drawings are essential for energy audits, commissioning, and retro-commissioning activities that ASHRAE standards address.

Building Codes (IBC / Local Amendments)

The International Building Code (IBC) and its local amendments frequently require as-built documentation as part of the permit closeout process. Specific requirements vary by jurisdiction, but common triggers include:

• Certificate of Occupancy: Many jurisdictions require as-built drawings before issuing a CO
• Fire safety compliance: As-built fire protection drawings for sprinkler and alarm systems
• ADA compliance: Verified accessibility dimensions for restrooms, corridors, and entries
• Structural modifications: As-built structural drawings when modifications are made

GSA (U.S. General Services Administration)

The GSA requires comprehensive as-built documentation for all federal buildings. Their BIM Guide Series specifies requirements for existing conditions documentation, including point cloud deliverables and BIM models at specified LOD levels. Federal projects involving renovation of existing GSA-managed facilities typically require as-built documentation as a first phase.

RICS (Royal Institution of Chartered Surveyors)

For international projects, RICS standards provide guidance on measured building surveys and as-built documentation. RICS defines survey categories from basic outline plans to full measured surveys with tolerances specified for each category.

As-built drawing costs vary based on building size, complexity, the number of drawing types required, and whether traditional measurement or 3D laser scanning is used. Understanding cost factors helps set realistic project budgets.

3D Laser Scanning Costs

When using 3D laser scanning to create as-built drawings, the cost includes two components: the scanning itself and the drawing production.

Cost Factors

• Building size (sqft): The primary cost driver for both scanning and drawing production
• Number of drawing types: Floor plans only vs. full set (plans, RCPs, sections, elevations, MEP)
• Building complexity: Simple open offices vs. dense MEP environments like hospitals or labs
• Number of floors: Multi-story buildings require scanning and drafting each level
• Access constraints: Occupied buildings, security requirements, and limited working hours add time
• Timeline: Rush delivery (25-50% premium) vs. standard turnaround
• CAD standards: Custom layer naming, symbology, and annotation standards add time

Scanning vs Traditional Cost Comparison

For small, simple spaces (under 5,000 SF), traditional manual measurement may be more cost-effective. For buildings over 10,000 SF or any project requiring MEP documentation, 3D laser scanning typically delivers better value due to faster field time, higher accuracy, and the bonus of receiving a re-measurable point cloud.

Note: Scanning costs scale more efficiently for larger buildings because equipment captures data faster than manual measurement. The break-even point is typically around 10,000-15,000 SF, above which scanning becomes the more economical option.

For a quick estimate, try our interactive cost calculator. For detailed pricing breakdowns, see our As-Built Drawings Cost Guide and 3D Scanning Cost Guide.

Ordering as-built drawing services from a professional scanning provider is straightforward. Here is what to prepare and what to expect through the process.

What to Prepare Before Requesting a Quote

• Building address and approximate square footage: This determines the scope of scanning required and provides the basis for initial pricing estimates.
• Drawing types needed: Specify which drawing types you require (floor plans, RCPs, elevations, sections, MEP). A full drawing set costs more than floor plans alone.
• Intended use: Are the drawings for a renovation design, permit application, facility management, or real estate transaction? This affects the level of detail required.
• CAD standards (if any): If your organization has specific layer naming conventions, annotation standards, or CAD templates, provide these upfront.
• Existing documentation: Share any existing drawings, even if outdated. They help the scanning team understand the building and identify areas requiring special attention.
• Access information: Note any access restrictions, security requirements, operating hours, or areas that may be difficult to reach (locked mechanical rooms, occupied patient rooms, etc.).
• Timeline requirements: Standard turnaround or rush delivery? This affects pricing and scheduling.

What to Expect During the Project