How Are Shop Drawings Reviewed Before Construction?
RIYADH, SAUDI ARABIA
Before construction begins on any engineering project, Shop Drawings go through a detailed review process to ensure they are ready for execution. This review is not simply about finding mistakes it is intended to verify that every execution detail is clear and that all project systems work together without conflicts.
In many projects, the challenge is not the design itself, but the execution details that only become apparent once work starts on site. That is why reviewing Shop Drawings is considered one of the most important steps in reducing errors, avoiding rework, and maintaining the quality of construction.
What Are Shop Drawings?
Shop Drawings are detailed construction drawings prepared based on the approved design drawings. Unlike design drawings, they include the technical details required by the construction team to carry out the work accurately on site.
These drawings show equipment locations, cable and pipe routes, actual dimensions, installation methods, and connection points between different systems, making them the primary reference during construction.
Shop Drawings are used across a wide range of engineering disciplines, including electrical systems, low-current systems, HVAC systems, mechanical works, and plumbing systems.
Why Are Shop Drawings Reviewed Before Construction?
Although the drawings may appear complete, construction often reveals issues that are not obvious during the design stage. The review process helps identify these issues before work begins, when correcting them is much easier, faster, and less expensive.
Reviewing Shop Drawings helps to:
Facilitate consultant approval.
Prevent rework and unexpected modifications.
Reduce construction errors
Detect clashes between different
Ensure the drawings match the approved design drawings.
How Are Shop Drawings Reviewed?
The review process involves several stages, with design engineers, site engineers, and coordination engineers working together to ensure every detail is accurate and practical.
1. Design Drawings and Specifications Review
Shop drawings are reviewed and compared with the approved design drawings and project documents to ensure that all details in the execution drawings match the approved design.
2. Verification of Dimensions and Levels
All dimensions and elevations are carefully checked, as even minor discrepancies can cause installation issues. This includes:
• Equipment and panel locations.
• Technical room dimensions.
• Wall and ceiling openings.
• Maintenance access spaces.
3. Coordination Between Engineering Disciplines
One of the main causes of project delays is
conflicts between different building systems.
Therefore, all disciplines are reviewed
together to ensure there are no clashes
between electrical systems, ELV systems,
mechanical works, and structural elements.
4. Review of Materials and Equipment
The specified materials and equipment are reviewed to ensure they comply with the approved project specifications, including:
• Cable types.
• Conduit sizes.
• Equipment models.
• Electrical ratings.
• Installation requirements.
• Manufacturer’s instructions.
5. Compliance with Codes and Standards
The drawings are reviewed to ensure compliance with all applicable safety requirements, installation methods, and industry standards, ensuring the systems are implemented according to engineering best practices.
6. Verification of On-Site Constructability
The design is reviewed to confirm that the work can be executed efficiently on-site, with proper equipment access, logical work sequencing, and no technical obstacles that could affect installation
The Role of BIM in Reviewing Shop Drawings
Today, Building Information Modeling (BIM) has become an essential tool for reviewing Shop Drawings, especially in large and complex projects.
Using a three-dimensional model, project teams can detect clashes between systems before construction begins. BIM also makes it easier to review service routes, equipment locations, and the relationship between different engineering disciplines, improving drawing accuracy and minimizing future modifications.
Common Issues Found During Shop Drawing Reviews
- Clashes between different building systems.
- Incorrect dimensions or elevations.
- Drawings that were not updated after design revisions.
- Inconsistencies between equipment schedules and drawings.
- Insufficient maintenance clearances.
- Materials or equipment that do not comply with project specifications.
The earlier these issues are identified, the easier and less expensive they are to resolve.
Can Construction Start Before Shop Drawings Are Approved?
Construction should not begin before the consultant approves the Shop Drawings. Any modification made after construction has started may require completed work to be dismantled and rebuilt, affecting both the project schedule and budget.
For this reason, construction teams should always work from the latest approved version of the drawings, which serves as the official project reference.
Reviewing Shop Drawings is a critical step in achieving efficient, high-quality construction. It helps identify problems before they appear on site, improves coordination between engineering disciplines, and minimizes errors that could affect project progress.
At Smart Directions, we carefully prepare and review Shop Drawings using a systematic engineering approach to ensure high-quality execution, reduce project risks, and deliver successful results from the very beginning.
