If you’re planning to have new windows or doors fitted, you’ve probably seen the term “Certass registered” mentioned by installers. It sounds like standard industry jargon — but it actually matters a great deal for your home, your building regulations compliance, and your legal protection if anything goes wrong.
Here’s what it actually means, in plain English.
What Is Certass?
Certass is a Competent Person Scheme (CPS), approved by the UK government, that allows registered installers to self-certify that replacement windows and doors comply with Building Regulations — without needing a separate visit and sign-off from your local council’s Building Control department.
It exists alongside similar schemes (like FENSA), and both serve the same core purpose: giving homeowners confidence that installed work meets national safety, thermal performance, and ventilation standards.
Why Does Building Regulation Compliance Matter?
Since 2002, replacing windows and external doors in England and Wales has been covered under Building Regulations — specifically Part L (thermal performance), Part N (glazing safety), and Part F (ventilation). This isn’t optional paperwork; it’s a legal requirement.
If your windows or doors are fitted without proper certification:
- You may struggle to prove compliance when you come to sell your home
- Conveyancing solicitors will usually ask for a compliance certificate during a house sale
- You have no formal, independent record that the work meets safety and efficiency standards
A Certass-registered installer handles this certification as part of the job, submitting the notification to your local authority and issuing you a compliance certificate once the work is signed off.
What Does Certass Registration Actually Check?
To become and remain Certass registered, installers must demonstrate:
- Technical competence in installation methods
- Compliance with current Building Regulations
- Ongoing quality assurance through regular audits and inspections
- Proper documentation and certification processes for every job
This isn’t a one-off badge — registered installers are audited on an ongoing basis to maintain their status, which gives homeowners an added layer of accountability beyond the initial installation.
What You’ll Receive as a Homeowner
When you use a Certass-registered installer, you should receive:
- A Certass compliance certificate, confirming the installation meets Building Regulations
- Notification to your local council, so there’s an official record of the work
- Documentation you can hand to solicitors if you sell your home later
Keep this paperwork safe — it’s genuinely one of the most commonly requested documents during a house sale, and missing certificates can slow down or complicate a sale.
How to Check an Installer Is Certass Registered
Before booking any window or door installation, it’s worth confirming registration directly:
- Ask the installer for their Certass registration number
- Check the Certass website registered installer search
- Ask to see an example of the compliance certificate they issue
A reputable installer will have no problem providing this information upfront — if they’re vague or reluctant, that’s worth treating as a red flag.
Certass and Your Guarantee
Certass registration is separate from (but complements) your product and installation guarantee. Registration confirms the work meets legal building standards; your guarantee covers the ongoing performance of the product and workmanship over time. A trustworthy installer should be able to clearly explain both to you before work begins.
Our Commitment
St Austell Bay Windows & Plastics is a Certass-registered installer, and every installation across St Austell, Cornwall and the surrounding areas is fully certified and compliant with current Building Regulations. Our own in-house fitting team — never sub-contracted — carries out every job on our uPVC windows and doors, backed by our full guarantee, so you always know exactly who is working on your home and to what standard.
Get in touch for a free quote, and ask us about your Certass certificate as part of the process — we’re always happy to talk you through it.
