What is a shop drawing in construction – A Detailed Guide | All about Shop Drawings in 2023

Construction projects require precision and accuracy to ensure that every component is installed correctly. However, the general construction drawings may not provide enough detail or information for the contractor and subcontractors to install each component precisely. This is where shop drawings come in.

Shop drawings are detailed and accurate drawings created by subcontractors or fabricators that provide vital information about each component’s installation. They help ensure that each element is installed correctly, prevent costly mistakes, and facilitate communication between the design team, contractor, and subcontractors. Let’s explore the importance of shop drawings in more detail.

What is a shop drawing in construction

Shop drawings are detailed drawings that are created by contractors, subcontractors, and fabricators to provide specific information about the materials, components, and systems that will be used in a building or infrastructure project. They are typically used to convey information about the fabrication, assembly, and installation of a particular element, such as a structural steel member, a mechanical system, or an architectural feature.

Some examples of shop drawings include:

  • Structural Steel Drawings: These are drawings that provide detailed information about the fabrication and assembly of structural steel members, including dimensions, tolerances, and welding details.
  • Mechanical Drawings: These are drawings that provide detailed information about the fabrication and installation of mechanical systems, such as HVAC, plumbing, and fire protection systems.
  • Electrical Drawings: These are drawings that provide detailed information about the fabrication and installation of electrical systems, such as lighting, power, and communication systems.
  • Millwork Drawings: These are drawings that provide detailed information about the fabrication and installation of custom architectural elements, such as cabinetry, millwork, and other decorative features.
  • Equipment Drawings: These are drawings that provide detailed information about the fabrication and installation of specialized equipment, such as elevators, escalators, and other mechanical systems.
  • Fabrication Drawings: These are drawings that provide detailed information about the fabrication process of a particular item, including cutting and bending schedules, welding symbols and details, etc.
  • Assembly Drawings: These are drawings that provide detailed information about the assembly of a particular item, including the location, orientation, and fastening of components.

Shop drawings are typically reviewed and approved by the architect, engineer, or the owner of the project before the fabrication and installation begin. 

Why Shop Drawings are so important?

Shop drawings are an important part of the construction process as they provide detailed information about the materials, components, and systems that will be used in a building or infrastructure project. They are critical to ensure that the final product will be built as per the design intent and specifications.

Here are a few key points on the importance of shop drawings:

  • Quality Control: Shop drawings provide detailed information about the fabrication, assembly, and installation of a particular element, which can be used to ensure that the final product meets the required quality standards.
  • Cost Control: Shop drawings help to identify any potential issues or conflicts before construction begins, which can help to reduce costs by minimizing the need for rework or change orders.
  • Communication: Shop drawings provide a clear and concise means of communication between the design team, contractor, and fabricator. This helps to ensure that everyone is on the same page and that any issues or concerns are addressed in a timely manner.
  • Compliance: Shop drawings are typically reviewed and approved by the architect, engineer, or the owner of the project, which helps to ensure that the final product will be built in compliance with the design intent, code requirements, and project specifications.
  • Safety: Shop drawings can help to improve the safety of a building or infrastructure project by identifying potential hazards and providing information on how to mitigate them.
  • Facility Management: Shop drawings provide an accurate and up-to-date digital representation of the facility, which can be used for maintenance, operation, and retrofitting of the building.

In summary, shop drawings play a crucial role in the construction process as they provide detailed information that is necessary to ensure that the final product is built to the highest standards, while also reducing costs, improving safety, and facilitating the management of the facility.

Who prepares the shop drawings?

Shop drawings are detailed, scaled drawings or diagrams that provide specific information about how various components of a construction project or manufactured product should be fabricated, assembled, and installed. These drawings serve as a bridge between the design and construction phases, offering precise instructions for builders, fabricators, and contractors.

Who Prepares Shop Drawings:

  1. Subcontractors: In many cases, subcontractors or specialized tradespeople prepare shop drawings for their specific scope of work. For example, steel fabricators create shop drawings for structural steel components, while cabinet makers produce shop drawings for custom cabinetry.

  2. Manufacturers: Manufacturers of pre-fabricated or custom-made building components, equipment, and machinery generate shop drawings to guide the production process.

  3. Design Professionals: In some instances, architects, engineers, or designers may create or review shop drawings to ensure they align with the project’s design intent and meet safety and code requirements.

  4. Drafters and CAD Technicians: Skilled drafters and computer-aided design (CAD) technicians are often responsible for creating the actual drawings based on the specifications provided by subcontractors or manufacturers.

  5. General Contractors: General contractors may also produce shop drawings for certain aspects of the project, especially when coordinating various trades or fabricators to ensure that components work together seamlessly.

How are Shop drawings created?

Creating accurate and detailed shop drawings requires a high level of skill and expertise. Here’s how the process usually works:

  1. Obtaining Design Drawings: The first step in creating shop drawings is obtaining the design drawings from the design team. These drawings provide the overall layout and design of the building.

  2. Reviewing Design Drawings: Once the design drawings are obtained, the subcontractor or fabricator reviews them to understand the design intent and specific requirements.

  3. Taking Measurements: Measurements of each component that requires a shop drawing are taken to ensure precise fabrication and installation.

  4. Creating the Shop Drawings: With the design intent and measurements in mind, the subcontractor or fabricator creates the shop drawings using specialized software.

  5. Reviewing the Shop Drawings: The shop drawings are reviewed by the subcontractor or fabricator and the design team to ensure accuracy and that they meet the project requirements.

  6. Revising the Shop Drawings: If any changes are required, the shop drawings are revised and reviewed again.

  7. Obtaining Final Approval: Once the shop drawings are accurate and meet the project requirements, they are approved by the design team and the contractor before fabrication and installation.

Point to remember while preparing a shop drawing

While preparing shop drawings, it is important to keep in mind the following points:

  • Compliance: The shop drawings must comply with the design intent, code requirements, and project specifications.
  • Quality: The shop drawings must provide accurate, detailed, and precise information about the fabrication, assembly, and installation of a particular element.
  • Communication: The shop drawings must be clear, concise, and easy to understand to facilitate communication between the design team, contractor, and fabricator.
  • Organization: The shop drawings must be organized and well-labeled, to make it easy to find the information needed.
  • Safety: The shop drawings must include information on how to mitigate potential hazards and improve safety.
  • Dimensioning and Tolerance: The shop drawings must include appropriate dimensions and tolerances to ensure that the final product meets the required quality standards.
  • Fabrication and Installation methods: The shop drawings must include information on the fabrication and installation methods, including cutting and bending schedules, welding symbols and details, etc.
  • Review and Approval: The shop drawings must be reviewed and approved by the architect, engineer, or the owner of the project before the fabrication and installation begin.
  • Update: The shop drawings must be kept up-to-date and reflect any changes or modifications that are made to the design or the project specifications.

By keeping these points in mind, the shop drawings will be more efficient and effective in communicating the design intent and ensuring that the final product meets the required standards, while also reducing costs, improving safety, and facilitating the management of the facility.

Classification of shop drawings

Shop drawings are classified into several types, which include:

  • Structural Shop Drawings: These drawings show the detailed layout and design of a building’s structural components, such as beams, columns, and foundations. They include details of the materials and sizes of the components, as well as any connections and fasteners.
  • Mechanical Shop Drawings: These drawings show the detailed layout and design of a building’s mechanical systems, such as HVAC, plumbing, and electrical systems. They include details of the materials, sizes, and locations of the components, as well as any connections and fasteners.
  • Architectural Shop Drawings: These drawings show the detailed layout and design of a building’s architectural components, such as walls, floors, and ceilings. They include details of the materials, sizes, and locations of the components, as well as any connections and fasteners.
  • Fire Protection Shop Drawings: These drawings show the detailed layout and design of a building’s fire protection systems, such as sprinklers, alarms, and fire extinguishers. They include details of the materials, sizes, and locations of the components, as well as any connections and fasteners.
  • Equipment Shop Drawings: These drawings show the detailed layout and design of equipment that is being installed in the building, such as elevators, escalators, and cranes. They include details of the materials, sizes, and locations of the components, as well as any connections and fasteners.
  • Specialty Shop Drawings: These drawings show the detailed layout and design of specialized or unique components of the building, such as acoustical systems, curtain walls, and skylights. They include details of the materials, sizes, and locations of the components, as well as any connections and fasteners.

The classification of shop drawings will vary depending on the project and the industry. These classifications are not exclusive and may overlap, but they help to organize the information and to identify the type of shop drawing that is being used.

Thing to avoid while preparing a shop drawing

While preparing shop drawings, it is important to avoid the following mistakes:

  • Inaccuracies: Avoid including inaccuracies or errors in the shop drawings as they can lead to confusion, errors, and rework during the construction process.
  • Lack of detail: Avoid providing insufficient or lack of detail in the shop drawings, as it can lead to confusion and errors during the fabrication and installation process.
  • Lack of clarity: Avoid using unclear or ambiguous language, symbols, or notation in the shop drawings as it can lead to confusion and errors during the fabrication and installation process.
  • Lack of organization: Avoid creating disorganized or poorly labeled shop drawings, as it can make it difficult to find the information needed.
  • Lack of review and approval: Avoid skipping the review and approval process of the shop drawings by the architect, engineer, or the owner of the project, as it can lead to errors and non-compliance with the design intent, code requirements, and the project specifications.
  • Lack of updating: Avoid not updating the shop drawings to reflect any changes or modifications that are made to the design or the project specifications.
  • Skipping safety precautions: Avoid skipping safety precautions, as they can lead to potential hazards and accidents during the fabrication and installation process.

By avoiding these mistakes, shop drawings will be more accurate, detailed, and precise, which will help to ensure that the final product meets the required standards, while also reducing costs, improving safety, and facilitating the management of the facility.

Shop drawing Global standards

There are several standards that govern the preparation and submission of shop drawings, these include:

  • American Institute of Architects (AIA) Document A201-2017: General Conditions of the Contract for Construction. This document includes provisions for the preparation, review, and approval of shop drawings by the architect.

  • American Society of Mechanical Engineers (ASME) Y14.24: Engineering Drawing Practices. This standard provides guidelines for the preparation and presentation of engineering drawings, including shop drawings.

  • American Welding Society (AWS) D1.1: Structural Welding Code – Steel. This standard includes provisions for the preparation and submission of shop drawings for steel structures, including welding details.

  • International Code Council (ICC) International Building Code (IBC). This code includes provisions for the preparation and submission of shop drawings for building components, including structural, mechanical, and electrical systems.

  • National Fire Protection Association (NFPA) 13: Standard for the Installation of Sprinkler Systems. This standard includes provisions for the preparation and submission of shop drawings for fire protection systems, including sprinkler systems.

  • National Institute of Standards and Technology (NIST) Special Publication 800-34: Contingency Planning Guide for Federal Information Systems. This guide provides recommendations for the preparation and submission of shop drawings for specialized or unique components of the building, such as acoustical systems, curtain walls, and skylights.

  • ASTM International: ASTM A480/A480M – Standard Specification for General Requirements for Flat-Rolled Stainless and Heat-Resisting Steel Plate, Sheet, and Strip. This standard provides guidelines for the preparation and submission of shop drawings for stainless steel components.
  • American National Standards Institute (ANSI): ANSI/ASME Y14.5M – Dimensioning and Tolerancing. This standard provides guidelines for the preparation and presentation of dimensioning and tolerancing on engineering drawings, including shop drawings.
  • National Wood Flooring Association (NWFA): NW GUIDELINES FOR SHOP DRAWINGS. This guide provides recommendations for the preparation and submission of shop drawings for wood flooring components, including hardwood flooring.
  • National Electrical Manufacturers Association (NEMA): NEMA Standards Publication No. 250 – Enclosures for Electrical Equipment (1000 Volts Maximum). This standard provides guidelines for the preparation and submission of shop drawings for electrical equipment enclosures.
  • The National Terrazzo and Mosaic Association (NTMA): Guidelines for Terrazzo Shop Drawings. This guide provides recommendations for the preparation and submission of shop drawings for terrazzo flooring components.
  • Sheet Metal and Air Conditioning Contractors’ National Association (SMACNA): SMACNA CAD Standard. This standard provides guidelines for the preparation and submission of shop drawings for sheet metal components, including ductwork and HVAC systems.

Shop drawing Indian standards

In India, there are several standards that govern the preparation and submission of shop drawings, these include:

  • Bureau of Indian Standards (BIS): IS 3764-1-2015 – Drawing Practice for Architectural, Structural, Mechanical, and Electrical Engineering – Part 1: General Principles. This standard provides guidelines for the preparation and presentation of engineering drawings, including shop drawings, for architectural, structural, mechanical, and electrical engineering.
  • Indian Roads Congress (IRC): IRC: 37-2012 – Guidelines for Preparation of Detailed Project Report (DPR) and Detailed Drawings. This standard provides guidelines for the preparation and submission of shop drawings for road and bridge projects.
  • Indian Institute of Architects (IIA): Guidelines for Preparation of Shop Drawings. This guide provides recommendations for the preparation and submission of shop drawings for architectural components, such as walls, floors, and ceilings.
  • Indian Society of Heating, Refrigerating and Air Conditioning Engineers (ISHRAE): ISHRAE Guidelines for Preparation of Shop Drawings. This guide provides recommendations for the preparation and submission of shop drawings for HVAC systems.
  • Indian Institute of Interior Designers (IIID): IIID Guidelines for Preparation of Shop Drawings. This guide provides recommendations for the preparation and submission of shop drawings for interior design components.
  • Indian Plumbing Association (IPA): IPA Guidelines for Preparation of Shop Drawings. This guide provides recommendations for the preparation and submission of shop drawings for plumbing systems.

What is the difference between construction drawings and shop drawings?

AspectConstruction DrawingsShop Drawings
PurposeProvide an overview of the entire projectOffer detailed instructions for specific components or systems
ScopeCover all aspects of the construction project, including architectural, structural, mechanical, electrical, and plumbing componentsFocus on a particular aspect or system within the project, such as steel structures, HVAC systems, cabinetry, or electrical panels
Detail LevelLess detailed, emphasizing overall design and spatial arrangementHighly detailed, specifying materials, dimensions, tolerances, assembly methods, hardware, and finishes
PreparationTypically created by architects, engineers, and design professionals through collaborative effortsPrepared by subcontractors, manufacturers, or specialized tradespeople with expertise in their respective areas
Approval ProcessSubmitted for approval to building departments, regulatory agencies, and other authorities to obtain permits and demonstrate complianceSubmitted for approval to the general contractor or construction manager to ensure they conform to design and quality standards
UseServe as a primary reference for contractors, builders, and tradespeople to understand the project’s design and scopeProvide specific instructions for fabricators, manufacturers, and subcontractors, guiding the production and assembly of individual components or systems

What is the difference between ifc drawings and shop drawings?

AspectIFC DrawingsShop Drawings
PurposeUsed for design collaboration and coordination in BIM systemsProvide production and installation instructions for specific components or systems
ScopeEncompass the entire construction projectFocus on specific project components or systems
Detail LevelComprehensive, including 3D models and metadataHighly detailed, specifying materials, dimensions, tolerances, and finishes
PreparationCreated by architects, engineers, and BIM specialistsProduced by subcontractors, manufacturers, or specialized tradespeople
Approval ProcessNot typically submitted for regulatory approvalSubmitted to the general contractor or construction manager for review and approval

What is the difference between shop drawing and coordination drawing?

AspectShop DrawingsCoordination Drawings
PurposeProvide detailed instructions for the fabrication and installation of specific building components or systems.Facilitate coordination among various trades and stakeholders by highlighting potential clashes and conflicts in the design.
ScopeFocus on individual components or systems within the project, such as steel structures, HVAC, or electrical systems.Encompass the entire project and aim to identify spatial and functional conflicts among different building systems.
Detail LevelHighly detailed, specifying materials, dimensions, tolerances, assembly methods, and finishes for fabrication and installation.Provide a visual representation of how different building systems interact and may include clash detection and resolution.
PreparationCreated by subcontractors, manufacturers, or specialized tradespeople based on project specifications.Prepared by design and coordination professionals to ensure that various building systems work harmoniously.
Approval ProcessSubmitted to the general contractor or construction manager for review and approval to ensure compliance with design and quality standards.Used for coordination purposes among project stakeholders and may not go through a formal approval process.

What is the difference between shop drawing and working drawing?

AspectShop DrawingsWorking Drawings
PurposeProvide detailed instructions for the fabrication and assembly of specific components or systemsProvide a comprehensive set of drawings for construction, including architectural, structural, mechanical, and electrical details
ScopeFocus on specific components or systems within the project, such as steel structures, HVAC systems, or cabinetryEncompass all aspects of the construction project, including architectural, structural, mechanical, electrical, and plumbing components
Detail LevelHighly detailed, specifying materials, dimensions, tolerances, assembly methods, hardware, and finishesComprehensive but may be less detailed for specific components compared to shop drawings
PreparationUsually prepared by subcontractors, manufacturers, or specialized tradespeople with expertise in their respective areasPrepared by architects, engineers, and design professionals as part of the project’s overall construction documentation
Approval ProcessSubmitted to the general contractor or construction manager for review and approval to ensure compliance with design and quality standardsPart of the overall construction document package and may require review and approval by regulatory authorities

What is the relationship between shop drawings and design drawings?

AspectShop DrawingsDesign Drawings
PurposeProvide detailed instructions for manufacturing and construction of specific building components or systems.Communicate the overall design intent and concept of the entire construction project.
ScopeFocus on specific components or systems within the project, such as structural elements, HVAC, millwork, etc.Encompass the entire project, including architectural, structural, mechanical, electrical, and other systems.
Detail LevelHighly detailed, specifying materials, dimensions, tolerances, assembly methods, and finishes for fabrication and installation.Less detailed, emphasizing the overall design concept, spatial layout, and relationships between building elements.
PreparationCreated by subcontractors, manufacturers, or specialized tradespeople with expertise in their respective areas.Generated by architects, engineers, and design professionals during the project’s design and planning phases.
Approval ProcessSubmitted to the general contractor or construction manager for review and approval to ensure compliance with design and quality standards.Reviewed by various stakeholders, including clients, architects, engineers, and regulatory authorities, to ensure alignment with design intent and code compliance.

FAQs about Shop Drawings

Who uses shop drawings?

Shop drawings are used by the contractor and subcontractors during the construction process to ensure that every component is installed correctly.

Can shop drawings be modified during construction?

Shop drawings can be modified during construction if necessary, but any changes must be approved by the design team and documented to ensure that they meet the project requirements.

Conclusion

Shop drawings are a vital part of every construction project. They provide a level of detail and accuracy that is not present in the general construction drawings, ensuring that every component is installed correctly. They also help prevent costly mistakes and safety hazards, facilitate communication between the design team, contractor, and subcontractors, and ensure that the final product meets the project requirements. Creating accurate shop drawings requires expertise and attention to detail, but the benefits are well worth the effort. By ensuring precision and accuracy, shop drawings can save time, money, and headaches during the construction process.

By Ananta

Ananta has more than 10 years of experience as a lecturer in civil engineering & a BIM Implementation Specialist.

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