Shop drawings and As-Built drawings are both critical components of the construction process, but they serve different purposes and are used at different stages of a project. Here’s a detailed comparison between the two:
1. Purpose
Shop Drawings:
- Purpose: Shop drawings are created to guide the fabrication, assembly, and installation of specific components in a construction project. They translate the design intent from the original construction drawings into detailed, actionable instructions for the contractors, fabricators, or suppliers. These drawings ensure that each part of the project is built according to the precise specifications needed for proper fit and function.
- When Used: Shop drawings are used before and during the construction phase. They are a prerequisite for the fabrication and installation of materials and components.
As-Built Drawings:
- Purpose: As-Built drawings document the final, completed condition of the project, showing exactly what was constructed. These drawings record any deviations or modifications from the original design that occurred during construction. The purpose is to provide an accurate representation of the finished project for future reference, maintenance, renovations, or legal documentation.
- When Used: As-Built drawings are produced after the construction is complete and serve as the official record of the project as it was actually built.
2. Creation and Responsibility
Shop Drawings:
- Creation: Shop drawings are typically created by contractors, subcontractors, fabricators, or suppliers. They are based on the Issued for Construction (IFC) drawings but contain much more detail, including exact dimensions, material specifications, and fabrication instructions.
- Responsibility: The responsibility for creating shop drawings lies with the party who is directly involved in the fabrication or installation of the specific component, such as steel fabricators, HVAC contractors, or cabinetry manufacturers.
As-Built Drawings:
- Creation: As-Built drawings are created by the contractor or construction team during and after the construction process. They start with the original construction drawings and are updated to reflect any changes that were made on-site during construction. These changes might include alterations to dimensions, materials, or layouts that differ from the original plan.
- Responsibility: The main contractor is usually responsible for ensuring that As-Built drawings are accurate and complete. This often involves marking up the original drawings during construction and then finalizing the As-Built drawings at the end of the project.
3. Level of Detail
Shop Drawings:
- Detail Level: Shop drawings are highly detailed and focused on specific elements of the project. They include precise dimensions, fabrication details, material specifications, and assembly instructions. These drawings are concerned with ensuring that individual components are fabricated and installed correctly.
- Examples of Detail: A shop drawing might show the exact bolt sizes, welding specifications, or cut lengths for structural steel beams, or the precise routing of HVAC ductwork.
As-Built Drawings:
- Detail Level: As-Built drawings reflect the final, constructed state of the entire project but are not as detailed as shop drawings in terms of fabrication specifics. Instead, they focus on documenting what was actually built, including any deviations from the original plan.
- Examples of Detail: As-Built drawings might show changes to the layout of walls, the location of piping and electrical conduits, or the final placement of windows and doors as they were actually installed on site.
4. Timing in the Project Lifecycle
Shop Drawings:
- Timing: Shop drawings are developed and used during the construction phase, after the IFC drawings have been issued but before the components are fabricated or installed. They are an essential part of the preparation and coordination process before actual construction activities begin.
- Role in Process: They are used to ensure that the components will be built to the correct specifications and fit properly within the overall project.
As-Built Drawings:
- Timing: As-Built drawings are produced after the construction phase is complete. They are finalized once all construction activities are done, and all changes and modifications have been documented.
- Role in Process: They serve as a record of what was actually constructed and are used for future reference, maintenance, and any potential renovations or expansions.
5. Review and Approval Process
Shop Drawings:
- Approval: Shop drawings must be reviewed and approved by the design team, including architects and engineers, before fabrication or installation begins. This review ensures that the shop drawings comply with the design intent as outlined in the IFC drawings and do not conflict with other aspects of the project.
- Changes: Any changes in the shop drawings typically require approval from the design team and may necessitate revisions to align with the project’s overall design.
As-Built Drawings:
- Approval: As-Built drawings are generally reviewed for accuracy by the contractor and the client or project owner. They may also be reviewed by the design team to ensure that they accurately reflect the constructed project. However, since As-Built drawings are a record of what was actually built, they do not typically require the same level of approval as shop drawings.
- Changes: As-Built drawings document changes that have already occurred during construction. They don’t require changes unless additional work or corrections are needed post-construction.
6. Use in Construction
Shop Drawings:
- Usage: Shop drawings are used during the construction process to guide the precise fabrication and installation of components. They ensure that each element is constructed to the exact specifications needed for proper assembly and integration into the overall project.
- Example: A steel fabricator uses shop drawings to cut and assemble steel beams according to the exact specifications provided, ensuring they will fit properly within the building’s structure.
As-Built Drawings:
- Usage: As-Built drawings are used after construction to provide an accurate record of the completed project. They are essential for future maintenance, repairs, renovations, and as legal documentation of the finished building.
- Example: Facility managers use As-Built drawings to locate plumbing lines or electrical conduits when performing maintenance or planning future modifications.
7. Examples of Each Type
Shop Drawings:
- Examples:
- Detailed drawings showing the fabrication and installation of structural steel components.
- Custom millwork drawings for cabinets, doors, and other interior finishes.
- Wiring diagrams for electrical systems, showing exact routing and connections.
As-Built Drawings:
- Examples:
- Updated architectural floor plans showing the final layout of rooms, walls, and doors.
- Revised MEP drawings indicating the actual locations of pipes, ducts, and electrical conduits.
- Structural drawings documenting any changes made to the foundation or framing during construction.
Conclusion
In summary, shop drawings are detailed, technical drawings created before and during construction to guide the fabrication and installation of individual components, ensuring they meet the project’s specifications. As-Built drawings, on the other hand, are a record of what was actually built, capturing all changes and modifications made during the construction process. Both types of drawings are crucial for the successful execution and documentation of a construction project, but they serve distinct roles at different stages of the project lifecycle.
