Key Elements of Fenestration Shop Drawings 

This bulletin is an excerpt of NGA Glass Technical Paper IN03-12 (2023) Key Elements of Fenestration System Shop Drawings, developed by members of the NGA Installing Committee. Download the complete technical paper to read details that are often overlooked in shop drawings, a general checklist of items that are included in shop drawings in an "order of assembly" format, and abbreviations and symbols commonly used in shop drawings. A free download is available at glass.org/store.  

Shop drawings for window and wall systems document and detail all requirements of design parameters, material ordering, fabrication and erection of the glazing subcontractor's scope of work. Failure to properly document and identify these requirements can result in numerous errors and project delays. 

What are shop drawings? 

Shop drawings are interpretations made by the glazing contractor or material suppliers of the architectural contract documents, including drawings and specifications. Shop drawings clearly and accurately represent the product being installed and allow the glazing contractor to properly order materials to fabricate and eventually install the glazing system. Shop drawings are reviewed and approved by architects for compliance with the contract documents. 

Shop drawings are developed by the glazing subcontractor primarily to show how, in conformance with the contract documents, it plans to fabricate and install the work. In addition to that, shop drawings play a bigger role throughout a project's life. It is important to convey the information to the architect, but there are several roles the shop drawings fill. 

How shop drawings may be used 

1. Internal to the glazing subcontractor, the shop drawings may be used to prepare quantity surveys or material takeoffs prior to issuing purchase orders for various portions of the work, such as glass, glazing accessories, gaskets, framing system components, finishing, sealants, fasteners, etc. 
2. The glazing subcontractor (or the framing supplier) also may use them as the basis for preparing fabrication documents or part drawings of the individual components that have to be cut to length and machined prior to shipping the produced parts to the site for assembly, or prior to any factory-assembled work as may be necessary, such as in unitized walls, or for any post-fabrication finishing that may be required (formed panels, formed copings, etc.) 
3. The general contractor may use them to coordinate not only the work of the glazing subcontractor with the construction of the building structure, but also with any of the other trades associated with the installation of the glazing system. This is critical when it comes to coordination of adjacent trades associated with air and water barriers. Coordination with other trades such as insulation and fire-safing installer (when not included in the glazing subcontractor's scope), a precast panel fabricator/erector into which windows may be set, or a masonry contractor creating rough openings for a strip window system, etc., may also be part of the general contractor's required coordination. 
4. Project consultants may also review them for compliance with project specifications. 
5. Code officials may review them to assess compliance with life-safety issues, such as safety or fire-rated glazing installations, or proper detailing of perimeter floor fire-safing installation. 
6. At project conclusion, the owner and building maintenance personnel may archive a copy for glazing system-related issues, such as ordering replacement parts, determining how to make any required repairs. 

Technical information typically included in shop drawings 

• Framing material type and finish type 
• Glass make-up 
• Types and sizes of framing members, including elevations with locating dimensions, plan and sections cuts 
• Connections to the building structure, or adjacent trades necessary to support the glazing system (precast panels, stud/sheathing/masonry construction, etc.) 
• Methods showing how the glass is glazed into the system and the glazing accessories required to do that (gaskets, setting blocks, edge blocks, etc.) 
• Transitions from the glazing systems' perimeter conditions to the adjacent construction 
• How the glazing systems will meet specified performance requirements of air, water, structural and building movement (for example, slab live-load deflection or seismic drift) 
• How the glazing system(s) interface with surrounding construction substrates 
• Fastener information including type, size, material, finish and spacing 
• Door size, rough opening, swing and hardware 

The level of detail in the shop drawing will vary based on the complexity of the project. For example, some of the information proposed would only be essential if the shop drawings are to include engineering details, which may not be required for more simple building projects.