VSI’s Product Certification Program Celebrates 25th Anniversary

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by Don Browne

Another Milestone in a Year Filled With Industry Milestones

There are times in the life of a good family when multiple anniversaries and watershed moments all happen simultaneously with much celebration. These periods of glad tidings are the rewards for a life well-lived, whose pillars are hard work, faith and belief in each other, and circling the wagons when the going gets tough.

The vinyl siding industry is very much like a family that strives to do the right things and grow together. In 2023, this is especially evident as they celebrate the 45th anniversary of the Vinyl Siding Institute (VSI) and the silver anniversary of VSI’s Product Certification Program.

“As I look through the timelines created for both commemorations, I’m reminded of the old Virginia Slims ad campaigns that were geared toward women and had that catchy tagline,” said Sara Krompholz, VSI’s Senior Director, Technical and Certification. “You’ve come a long way, baby!”

You can certainly appreciate Sara’s sentiments considering the program’s humble beginnings.


“The vinyl siding industry, pre-1998, was like the ‘wild, wild west,’” she explained. “There was no consistency in the products’ quality and poor consumer confidence. The Product Certification Program brought all the manufacturers together to develop a robust offering.”

VSI was founded in 1978.  In the late 90’s, they worked with ATI (now Intertek) to start a Product Certification Program focused on vinyl siding until 2010. “The program’s goal was standardizing the industry as a whole so that all manufacturers were on a level playing field and that products were consistently produced and distributed to the standards established,” Sara noted. “The program was also designed to achieve greater consumer confidence."

VSI wanted to re-write the vinyl siding story through the Product Certification Program because there were products made in previous decades that performed poorly and created this stigma for the industry. 

In 2006, standards for color were added, and in 2008, wind load addition was also included in the scope of testing – which became a critical component of the program. In 2009, the Certification Oversight Committee (COC) expanded the scope to include polypropylene siding in 2010. This leg work paved the way for ASTM D7254 – a new polypropylene siding standard for created through the VSI Technical Committee.

In 2011, the COC came together to work on the third product type – insulated vinyl siding – which led to the creation of ASTM D7793, a specification that establishes requirements for insulated vinyl siding. And so, by 2012, the VSI Product Certification would recognize multiple types of polymeric cladding – polypropylene siding, insulated vinyl siding and original vinyl siding lines. With all three product types added, VSI’s Product Certification Program would now cover 500-600 certified products.

“At that time, VSI now had a comprehensive and more widely-recognized program,” Sara said. “The new standards we established led to greater involvement of VSI in the ASTM arena in terms of maintenance, continuous improvement and adherence with the standards. The standards recognized through ASTM are also recognized in the International Residential Code (IRC) and International Building Code (IBC).”

In 2015, the COC recognized a need to improve in-plant impact testing processes. This was a commendable effort by the committee to identify an opportunity to establish fair play with one uniform tester, which led to the creation of a biennial impact round-robin study that VSI still conducts today.

Taking It To The Next Level

During a review of the program’s first 20 years in 2019, VSI decided to move the Product Certification Program to the next level: an ISO/IEC 17065 accreditation program with certification granted by Intertek as the Certification Body.

During the next three years, considerable work took place to transform the Product Certification Program from its 1998 origins to the current ISO/IEC 17065 accreditation. The foundational certification scheme achievement represented a significant turning point for the program, VSI and the vinyl siding industry. It came with a newly branded certification mark and the implementation of two new deliverables that are publicly available and renewed annually:

  • Product Certification Listing (PCL): A published authoritative document declaring that a product(s) complies with recognized standard(s). The PCLs are mandatory for the product certification program as they establish ASTM standard compliance on a specific product type.
  • Product Evaluation Report (PER): A published authoritative document that conveys how a product(s) complies with recognized standards AND requirements of building codes. The PERs are optional but are more robust documents, demonstrating the most compliance. They can be used to replace an existing evaluation report that a member obtained through another code agency, or it can be promoted as a new addition.

When the VSI Product Certification Program was officially relaunched to the VSI membership in August 2021, it represented 702 certified products. Soon after the relaunch, the program added a fourth product type: Backed Siding (ASTM D7445).

What’s Next?

Never resting on its laurels, VSI foresees an even brighter future for the Product Certification Program as it grows in direct relationship with the burgeoning vinyl siding industry.

“The sky’s the limit,” Sara said proudly. “We are continuing to evolve and expand our scope as evidenced by the addition of backed siding. We are working on recognizing Canadian certification to the National Building Code of Canada (NBC).  In the future, we might consider adding accessories and other PVC-related materials, and a scheme has been written to allow us to include expansion opportunities, which could also expand membership.”

Congratulations to VSI on the Product Certification Program’s 25th anniversary. You’ve come a long way, baby!


Don Browne is a writer, entrepreneur and local legislator who believes that the power of words can change the world. He provides unique writing services for clients in the construction, health care, IT and hospitality sectors. He has a passion for small business and start-ups, as well as writing about Irish history, family and corporate biographies. As a homeowner and father of four who is passionate about community development, Don looks forward to writing more about the exciting possibilities of creating traditional neighborhoods and more sustainable communities using modern materials.