What’s in Your Spec? A Checklist for Glazing Contractors

Sections:

• Common Specification Issues
• Looking in All the Right Places
• Valuable Resources
• Help from Vitro Glass
• Summary

Awareness, Diligence Key to Spotting Errors and Deviations in Glass Specifications

by Steve Marino

Premium unitized curtain wall and custom-built façades are par for the course in today’s highly creative building designs. Framed by tightening schedules and smaller budgets, successful commercial building projects need all stakeholders pulling on the same rope.

With the increasing complexity of façades, glazing contractors are relying heavily on accurate glass specifications to carry out their jobs. From project conception to completion, specifications provide a necessary “check and balance” to ensure that the proper products are being used and that current industry standards are being followed.

Although glazing contractors need to follow industry best practices, such as proper procedures for glass setting and using the proper glazing sealants, when installing the fabricated product, it’s equally important for them to review the glass specifications in their entirety to identify any “red flags,” errors, deviations from industry standards, special requirements or specific architect requests.

That’s not to say the entire responsibility falls on the glazing contractor. Because not all specifications are created equal, every party in the supply chain that receives the specification for a particular project—architect/specifier, general contractor, fabricator, raw materials suppliers—is accountable for ensuring that the product it manufactures complies with current standards.

An enormous amount of detail makes up a specification. It can address edicts ranging from general industry-accepted practices to precise performance criteria, such as glass characteristics, thermal and optical properties, and surface orientation for low-e coatings in an insulating glass unit (IGU). Yet, with building designs becoming more intricate and complex, it’s increasingly likely that an architect or specifier will add a spec to a construction document that deviates from industry standards.

So, how can glazing contractors best ensure that nothing falls through the cracks, and that the installation of the fabricated IGUs will comply with the specification and meet all stakeholder expectations?

Common Specification Issues

With hundreds of potential variables in any single glass specification, it’s understandable that a detail might get overlooked at any point in the process. The impact of such an oversight, though, can range from a developer who is dissatisfied with the appearance of the constructed building to the replacement of all the glass on a project because a performance specification was missed. So, regardless of the fallout, there is a “price to pay” for an inaccurate spec.

It’s not a stretch to say that a successful project—one that is completed on time and on budget, and that meets the expectations of the architect, building owner and all other stakeholders—hinges to a large extent on accurate specifications that comply with current industry standards. Being aware of and staying on top of potential issues serves the whole supply chain well. At each stage, it’s a good idea to conduct a “self-check” by reviewing the following questions:

• Are critical specs for the project properly addressed and highlighted sufficiently?
• Do generic specifications (e.g., general guidelines for glazing) reflect the most current language and standards?
• Is the glazing product written into the glass specification still manufactured by the supplier?
• Does the glass product specified for the project meet or exceed the related ASTM standard?
• What process is in place to ensure that changes to the specs are properly communicated?

Identifying issues in a specification doesn’t require a “needle in a haystack” approach. Checking for these common errors first can often quickly reveal inaccuracies:

• Copied and pasted specs. Although a time-saver, copying and pasting information from similar projects can result in references to incorrect products and documents that have been decommissioned. Even though specifications contain standard, generic language, it’s critical to review that language for each project, as glass specs and building codes occasionally change.
• Outdated standard and test method references. Obsolete standards and test methods can yield additional costs or installations that aren’t up to code. In addition, customers can receive inferior products or products that don’t meet current standards. Be aware of industry performance standards that have been updated or withdrawn, and double-check that any standard referenced in a specification reflects the most current version.
• Incorrect products. This issue manifests itself in several ways, including an erroneous or discontinued product that has been specified for a specific application, or a product brand that doesn’t correspond to the specified manufacturer. It’s a good idea to question specifications of custom products (e.g., tempered glass might not be needed to meet code). Also make sure that treatments such as low-e coatings, opacifiers and frits are appropriate for the surfaces in IGUs and spandrels.

Other areas to check include:

• Master Format numbers – Are they current?
• Referenced companies and suppliers – Are they still in business?
• Consistency of requirements – Do they agree across all sections of the spec document?
• Performance requirements attributed to specific products – Are they correct?
• Composition of the product being specified – Is the information provided sufficiently specific?

Once issues are identified, it’s critical that glazing contractors inform their subcontractors.

Looking in All the Right Places

So, the specification for a project arrives, and all seems to be in order, a fairly standard job.

Or Is It?

Perhaps the project isn’t so “standard.” If glazing contractors focus only on, for instance, the performance criteria for the glass makeup or received just a few select pages of the specification—not the entire Master Spec document—key information could be missed, resulting in a building that falls short of expectations.

Consider the Following Situation:

The architect has developed a very detailed spec that calls for heat-treated glass to meet the strength criteria for the building. To avoid a distorted, wavy look, the architect designates a “critical performance spec” for flatness. However, this information ends up in a section of the specification that other parts of the supply chain don’t typically review. The resulting glass product does not meet the architect’s requirements and he or she starts looking for a supplier to blame.

Although the work glazing contractors perform is based only on what the general contractor or architect provides, conducting a little “detective work” can go a long way. Check the entire specification, if feasible, for deviations or critical performance requirements that may be in a different part of the specification.

In addition, communication with upstream and downstream partners is vital. Because they are often more familiar with the overall scope of a project, general contractors can provide valuable insight into the visibility of, or expectations for, the project. For example, the glass specification for a new building being constructed in a major city and surrounded by iconic structures will likely have unique characteristics – perhaps the ASTM specification for a ¼-inch coating void is changing to ⅛-inch because the glass is in a high-traffic area of the building. Knowing the project’s prominence, the general contractor can “tip off” the glazing contractor of a potential deviation in the specs, such as a requirement that is tighter than normal ASTM specifications.

Valuable Resources

Several major trade organizations have developed publications or provide guidance that glazing contractors can reference to ensure that they are following the most-recent industry best practices. These organizations include:

• National Glass Association (NGA): Serves glazing contractors, glass fabricators, full-service glass companies, primary glass manufacturers and suppliers throughout the architectural glass and metals industry. The NGA’s Glass Association of North America (GANA) technical manuals and guidance documents remain some of the industry's most trusted resources. Developed, reviewed and approved by committees representing manufacturers, fabricators, glazing contractors and other industry organizations, the manual provides vetted guidance and best practices that help support quality, consistency and performance across the glazing industry. 
• Fenestration & Glazing Industry Alliance (FGIA): A leading trade association dedicated to advancing the glass, glazing and fenestration industries through research, consensus-based standards, product certification, advocacy, education and professional development. Formed through the unification of the American Architectural Manufacturers Association (AAMA) and the Insulating Glass Manufacturers Alliance (IGMA), FGIA works to improve home and building performance through technologies and standards. FGIA is widely recognized as a trusted industry resource and develops many of the performance standards, testing methods and certification programs used throughout the architectural glass and fenestration market. 
• American National Standards Institute (ANSI): Coordinates and oversees the U.S. voluntary standards and conformity assessment system. Founded in 1918, ANSI works with industry, government and other stakeholders to promote the development of consensus-based standards that improve quality, safety, efficiency and global competitiveness. While ANSI does not develop standards itself, it accredits standards developers, approves American National Standards and provides a framework that helps ensure consistency and trust across industries. ANSI also represents U.S. interests in international standardization activities and serves as a neutral forum for collaboration on national and global priorities. 
• American Society for Testing and Materials (ASTM): A globally recognized standards organization that develops and publishes voluntary consensus standards for a wide range of materials, products, systems and services. Through collaboration among manufacturers, engineers, architects, scientists, government agencies and industry experts, ASTM creates technical standards that help improve product quality, safety, performance and reliability. ASTM standards are widely used throughout the construction, manufacturing, transportation and materials industries, providing a common framework for testing, specification and best practices.
• National Fenestration Rating Council (NFRC): Develops and administers standardized energy performance ratings for windows, doors, skylights and attachment products. Through its certification and labeling programs, NFRC provides consistent, third-party verified ratings for key performance metrics such as U-value, Solar Heat Gain Coefficient (SHGC), Visible Light Transmittance (VLT) and Condensation Resistance. These ratings help architects, builders, manufacturers and consumers compare products and make informed decisions about energy efficiency, building performance and code compliance. NFRC ratings are widely referenced by ENERGY STAR^®, building codes and the fenestration industry. 
• U.S. Green Building Council (USGBC): Dedicated to improving the sustainability, health, resilience and performance of buildings and communities, USGBC is best known for developing and administering LEED^® (Leadership in Energy and Environmental Design), the world's most widely used green building certification program. USGBC's mission is to transform the built environment by providing tools, standards, education and certification programs that help building owners, architects, engineers, contractors and manufacturers create healthier, more efficient and environmentally responsible spaces.
• American Bird Conservancy (ABC): Committed to conserving birds and their habitats across the Americas. Through research, advocacy and model building standards, ABC has become a leading authority on bird-friendly design, helping shape legislation, building codes and best practices aimed at reducing bird collisions with glass. As bird-friendly building requirements continue to expand across North America, glazing contractors, architects and specifiers increasingly rely on ABC's guidance to identify compliant glazing products and design strategies.  
• International Code Council (ICC): Develops and maintains the model building codes and standards used throughout the United States and many countries worldwide. Best known for publishing the International Codes (I-Codes), ICC helps establish minimum requirements for building safety, sustainability, resilience and performance. ICC codes, including the International Building Code (IBC), serve as the foundation for many glazing requirements used by architects, code officials and contractors, addressing critical issues such as safety glazing, wind load resistance, fire-rated glazing, energy performance and building envelope compliance.  

Help From Vitro Glass

A complement to these industry resources is Vitro's Construct an IGU tool, which allows glazing contractors to search, build and compare virtual glazing configurations, generate CSI-format specifications and evaluate performance characteristics for Vitro glass products. 

For projects requiring additional support, Vitro also offers a robust suite of digital resources, including performance calculators, technical data sheets and  BIM objects.

Architects and glazing professionals can also access Vitro's Project & Case Study Gallery to see how glass products perform in real-world applications, request samples for hands-on evaluation and connect directly with architectural and technical representatives for project-specific guidance. 

Together, these resources help simplify specification development, improve decision-making and reduce the risk of costly errors by ensuring project teams have access to accurate, up-to-date performance data and technical expertise throughout the design and construction process. 

Summary

One of the keys to a successful building project – one that achieves the look architects envisioned when they designed and spec’d the job – involves the development of and adherence to accurate specifications.

Architects set the tone for building projects, but every other element in the supply chain, including the glazing contractor, fabricator and raw materials suppliers, is responsible not only for providing their selected component in compliance with the final glass specification but also ensuring that those specs are accurate and thorough and reflect the most current industry standards.

Numerous resources, such as GANA/NGA, IGMA and AAMA, supply industry best practices, recommendations and specifications that are readily available to help in the glass-specification process. Each of these organizations comprises experienced professionals, who serve as “voices of the industry” to develop the recommendations and best practices for the architectural glass trade.

To learn more about the glass-specification process and helpful resources for writing clear, up-to-date specs, visit vitroglazings.com or call the Vitro Architectural Services Team at 1-855-VTRO-GLS (887-6457).