Answer extracted from the Glazing Insider podcast — listen to the full episode below.
How many product approvals are currently registered on the PLC scheme database?
The PLC scheme database now has approximately 80 approval companies registered, with one company in particular holding over 2,500 individual product approvals that customers can filter and drill down to find exactly what they need.
The scale of this database reflects the growing importance of Part L Compliance certification in the fenestration industry. As John Warburton explains in the episode, ER Certification manages this approval registry to make it accessible for customers searching for compliant products.
A searchable database built for customer convenience
The sheer volume of approvals — with one company alone holding over 2,500 entries — would be unwieldy without a proper filtering system. The database structure allows customers to drill down into specific criteria rather than wade through thousands of unfiltered entries.
This level of organization is important because fenestration products vary enormously in specification, material, glazing configuration, and performance rating. A builder or installer searching for a specific window type or door specification needs to find matching approvals quickly and accurately.
The fact that ER Certification chose to build filtering and drill-down functionality into the database signals a user-centred approach to what could otherwise be a static approval list.
"I think we provide a very, very good service. Customers seem to appreciate what we do. I think we're firm but fair."
John Warburton — Managing Director, ER Certification Ltd. Warburton started his career in the fenestration industry in the mid-1980s at a small PVC window fabricator in Lancashire, where he learned manufacturing from the ground up. Over three decades, he held roles as field technician, exports manager, technical manager at Commolin, and product development specialist at Vika and Epwin, before joining the Building Research Establishment (BRE) in Watford to help establish certification schemes for windows and doors. He purchased ER Certification from founder Bill Keaton three years before this interview.
What makes this database particularly valuable is its direct connection to real-world compliance. Products on the registry have undergone rigorous testing and certification, so filtering through approved entries gives customers confidence that they are selecting genuinely compliant solutions.
If you want to understand more about how the PLC scheme was established, the specific standards it covers, and how it compares to other certification approaches, the full episode explores the broader context of thermal performance testing and certification governance in the fenestration sector.
See also
What is the PLC scheme and how does it differ from other thermal performance certification databases?
The PLC scheme, which stands for Part L Compliance, was set up last year and provides approvals for energy ratings and U-values for windows and doors, offering a centralized database distinct from other legacy certification systems.
Why are trickle vents problematic in modern thermally efficient windows?
Trickle vents destroy the thermal performance of highly efficient windows by putting holes through them. A government study published in 2019 found that they significantly reduce the energy efficiency gains achieved through advanced glazing and framing.
What is the typical failure rate for windows and doors during certification testing?
The failure rate is around 70% per visit when testing windows and doors across all factors, meaning it is statistically unlikely for products to pass through certification without encountering at least one issue that requires remediation.