A Detailed Comparison – IFC Drawings vs Shop Drawings

In every construction project, there are several steps that combine to form the complete building lifecycle.

Each of these has a specific set of activities depending on the place in the lifecycle where it exists. For example, during the concept design phase, professionals create the first design of a building.

Based on this, an output is obtained from every step. The concept design phase produces sketches, massing studies, and conceptual floor plans.

So, we can say these contract drawings form the foundation of the next step.

Now, where do the IFC, or what it stands for, “Issued for Construction” drawings all go? And we will also see the comparison between IFC drawings vs shop drawings.

But why do we need to understand the difference between IFC and shop drawings? To know that we have to understand the basics.

What are IFC Drawings in Construction?

So, IFC drawings are the final approved drawing sets that come from the design teams.

These drawings provide the on-site teams with a clear idea of the specifications for a project. The primary role of these is to translate conceptual designs and engineering plans into practical executions.

Back then, professionals had to work on assumptions, and things mentioned in drawings were not absolute. However, today’s BIM technologies, such as federated modeling and common data environments, support better IFC documentation.

The ISO 19650-5:2023 states this formally, about the information management and security for the delivery phase of building projects. It provides a framework that allows the IFC drawings to function with a status code. For instance, S4 for ‘Suitable for Manufacture and Construction’ would be a standardized code for every stakeholder involved.

Now, before we go deeper into the purpose of these construction drawings, let’s first understand shop drawings briefly.

There are several instances where the industry gets ambiguous while dealing with these.

What are Shop Drawings?

Shop drawings are the detailed drawings and diagrams, and it is not common only in the construction industry.

However, the AEC industry is the one where every project has a separate set of shop drawings for architecture, structure, and MEP.
It is the ultimate output that on-site teams use to execute construction activities. In modern construction projects, BIM models support the generation of accurate shop drawings.

This set of construction documentation can show detailed structural drawings and precise installation instructions for various components.

For example, the Riyadh Metro’s Qsar Al Hokm Downtown Station was such a project, where Pinnacle provided detailed MEP shop drawings prepared from tender-issued IFC drawings.

Now that we are aware of the basics of these two types of drawings, let’s get into knowing their purpose.

Purpose of IFC Drawings & Shop Drawings

IFC Drawings

Here are the key purposes of IFC drawings in construction:

Execution: The IFC drawings serve a primary purpose during the pre-construction stages. It brings all the direct stakeholders, such as the general contractor, builders, and owner, on the same page. The detailed view of sections, elevations, and other documentation comes here, ensuring they are compliant with the applicable codes. It is the foundation that outlines the exact details and specifications of a building, infrastructure, or structural steel.

Coordination: Here, coordination refers to a slightly different thing from the known model coordination. The IFC drawings rather help coordinate the efforts of the contractors and subcontractors by acting as a reference for change orders. In simple words, these drawings help both parties understand the design intent from the same point of view, ensuring that their works are aligned.

Compliance: Compliance is a critical factor in any construction project across the world. The process involves sharing the building plans with the regulatory authorities to get their approval. Since IFC drawings have details and exact design specifications of a building, along with the floor, fire protection plans, sections, and elevation, projects use them for compliance approval.
So these are the common purposes, but very critical purposes that the IFC drawings serve in construction projects.

Now, let’s move on to shop drawings.

Shop Drawings

Shop drawings play a vital role in guiding construction activities on the site, prepared after professionals review comments on the IFC. These drawings have the detailed information that facilitates pre-fabrication, installation, and assembly of components. Here are the key purposes of shop drawings:

Clarification and Visualization: The shop drawings are no longer a concept thing in construction documents. They give the practical scenario of how a system is to be installed or a structure is to be built. So, for various disciplines, such as architectural or civil plans, there are separate drawings. These drawings also have detailed instructions for specific component installations.

Coordination: Here, we are talking about multidisciplinary coordination in a construction project. BIM professionals coordinate different trades and merge them in a federated model; the shop drawings are the final output for that. It reflects how different trades, such as the HVAC or MEP piping, are to be placed in alignment with the structural parts.

Customization: These drawings are customizable with reference to a project’s unique needs in the construction process. The general IFC architectural and structural working drawings do not have such modifications. While professionals use it for a reference to see what was originally there, the shop drawings reflect everything. These include variations, modifications, and specific conditions that meet client expectations and local building codes.

Quality Control: Since shop drawings hold the final specifications and instructions for practical execution on the site, it is a great source for quality control. For example, fabricators receive the shop drawings as the only source of information. When prefabrication is done, they refer to the drawing to ensure the required quality is met. Even construction teams refer to the shop drawings for validating construction work on a daily basis. However, things have gotten more advanced, and engineers now also use an as-built model to validate work on site.

Now, let’s have a look at the differences that make these two separate.

IFC vs Shop Drawings: The Difference

Now, if we are not looking over the review process of these two types of drawings, we won’t fully understand the difference. There are significant differences in the steps that professionals undertake under the review process.

IFC vs Shop Drawing: Review Process

The review process of these two drawings itself creates differentiation. Professionals use these processes to facilitate seamless collaboration and data exchange, and also provide execution clarity.

Final Thoughts

IFC drawings and shop drawings are both critical elements of any construction project. The understanding of where these fall in the course of a complete project and their review process makes them different. Professionals use IFC drawings to get permits from regulatory bodies, and it aligns every stakeholder with the design intent. On the other hand, shop drawings are like detailed blueprints that guide the on-site teams through construction activities. If you are looking for detailed construction documentation, Pinnacle offers tailored expertise for your unique project needs.

FAQ

Who prepares shop drawings vs IFC drawings?

Usually, architects, designers, and consulting engineering firms prepare the IFC drawings, whereas the shop drawings are prepared from the IFC by contractors, subcontractors, or fabricators.

Can shop drawings replace IFC drawings in a construction project?

No, because IFC drawing sets work as a standard against which professionals review shop drawings.

What does IFC stand for in construction, and is it the same as “Issued for Certification”?

No, IFC in construction always refers to Issued for Construction, as through these drawings GCs represent the approved design.

How do IFC drawings relate to ISO 19650 status codes (e.g., S4)?

The ISO 19650 framework allows construction professionals to assign standardized ‘status codes’ to particular IFC drawings or models. This helps differentiate drawings that are validated for construction from the ones that may undergo change orders.

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