Who Is Responsible for As-Built Drawings?

 As-built drawings play a critical role in construction projects. They reflect what was actually built on site, not just what was planned. Yet many teams still ask a basic but important question: who is responsible for as-built drawings? The answer depends on the project structure, contracts, and level of coordination between stakeholders.

This article breaks down responsibilities clearly and explains how modern tools like BIM and shop drawings support accurate as-built documentation.

What Are As-Built Drawings?

As-built drawings are revised construction documents that show the final installed conditions of a building. They include changes made during construction, such as routing adjustments, material substitutions, equipment locations, and dimension updates.

These drawings are essential for facility management, future renovations, maintenance planning, and legal documentation. Because of their long-term value, accuracy is non-negotiable.

Primary Responsibility: Contractors

In most projects, the general contractor holds the primary responsibility for as-built drawings. This is because contractors are closest to on-site activities and manage daily construction changes.

Subcontractors also play a direct role. Each trade is responsible for documenting changes within its scope, such as mechanical, electrical, plumbing, or fire protection systems. For example, HVAC contractors often rely on hvac shop drawing services to track field modifications and equipment placements accurately before those updates are transferred into as-built drawings.

The general contractor then compiles all trade-level updates into a complete as-built set.

Role of Subcontractors and Trade Specialists

Subcontractors are responsible for providing redline markups that reflect actual installations. These markups include changes in routing, elevations, sizes, and connections.

Mechanical and MEP trades are especially critical because their systems are complex and often change due to coordination clashes. Accurate documentation at this level reduces costly errors later and supports smoother handover to building owners.

Engineers and Designers: Limited but Important Involvement

Designers and engineers are not usually responsible for preparing as-built drawings, but they may review them for consistency. Their role is more advisory unless the contract specifically states otherwise.

In design-build or BIM-led projects, engineers may contribute directly by updating coordinated models, especially when the project requires a defined BIM LOD (Level of Development) for handover.

BIM Teams and As-Built Models

With the rise of Building Information Modelling, many projects now deliver as-built information as a digital model rather than only 2D drawings.

BIM teams are responsible for updating models based on verified site data, laser scans, and approved redlines. When a project targets higher BIM LOD levels, such as LOD 400 or LOD 500, the responsibility for accuracy becomes even more structured and documented.

BIM-based as-built models provide better clarity, clash-free coordination, and long-term value for facility managers.

Owner’s Role in Verification

While owners are not responsible for creating as-built drawings, they are responsible for reviewing and approving them. Owners may also hire third-party consultants to audit the accuracy of as-built documentation before final acceptance.

Clear expectations set at the contract stage help avoid disputes and ensure the delivered as-builts meet operational needs.

Why Responsibility Must Be Clearly Defined

Unclear responsibility often leads to incomplete or inaccurate as-built drawings. This creates problems during inspections, maintenance, renovations, and resale.

To avoid confusion, contracts should clearly define:

• Who documents site changes

• Required drawing formats (2D or BIM)

• Target BIM LOD for as-built deliverables

• Submission timelines and approval process

Clear ownership ensures accountability and better project outcomes.

Final Thoughts

So, who is responsible for as-built drawings? In most cases, the general contractor carries the responsibility, supported by subcontractors, BIM teams, and trade specialists. Engineers and owners play review and verification roles, but accuracy starts on site.

With proper coordination, professional shop drawing support, and clearly defined BIM LOD requirements, as-built drawings become a valuable asset rather than an afterthought.