As Built Drawing
Definition
An as built drawing is a revised set of construction documents that accurately depicts the actual dimensions, locations, and specifications of a completed construction project. These drawings serve as the definitive record of what was actually built, as opposed to what was originally designed or planned. As built drawings are essential in surveying, construction management, and facility maintenance.
Purpose and Importance
As built drawings fulfill several critical functions in the construction and surveying industry:
Documentation: They provide an accurate permanent record of the final constructed conditions for future reference, maintenance, and renovations.
Liability Protection: These drawings protect both contractors and owners by documenting variations from original plans and establishing a baseline for future disputes or insurance claims.
Future Operations: Facility managers, maintenance teams, and future contractors rely on as built drawings to understand utility locations, structural elements, and system configurations.
Regulatory Compliance: Many jurisdictions require as built drawings for final project closeout and permit sign-off.
Key Differences from Design Drawings
Design drawings represent the architect's or engineer's intent and specifications before construction begins. As built drawings, however, reflect the reality of what was constructed. These differences may include:
Content and Components
Typical as built drawings include:
Preparation Methods
Surveyors and construction professionals prepare as built drawings using several approaches:
Field Measurement: Direct measurement of constructed elements using surveying instruments and tools.
Comparison Markup: Marking up original construction documents with actual conditions as observed.
Digital Scanning: Using laser scanning and photogrammetry to capture precise three-dimensional data.
Photography and Documentation: Supporting visual records alongside measured dimensions.
Standards and Best Practices
Professional as built drawing preparation should follow established standards:
Digital Evolution
Modern surveying increasingly employs Building Information Modeling (BIM) and laser scanning technology to create as built drawings. These technologies provide:
Challenges
Accurate as built drawings require careful attention and resources:
Conclusion
As built drawings represent the intersection of design intent and construction reality. In surveying practice, they serve as the authoritative record of constructed conditions, essential for project closeout, facility management, and future modifications. Accurate as built documentation protects stakeholders and provides reliable information for the operational life of constructed facilities.