Certifications and trade bodies: what they actually mean
Short answer
Certifications and trade body memberships raise the floor: an audited process, a complaints procedure, and — in the best schemes — an insurance fund that pays out if the company goes bust. Always verify the logo on the trade body's own register, never on the company's website alone.
Why certifications matter
The biggest dormer risks happen years after the install: a leak, a structural defect, a company that no longer exists. A certified company belongs to a scheme that gives you a place to go when the original contractor cannot — or will not — help.
Which ones to look for
- VLOK — Dutch joinery and dormer trade body, has a dispute scheme.
- Bouwgarant / Woningborg — insurance-backed completion and after-care warranties.
- SKG-IKOB — product certification for frames and components.
- KOMO — product/process certificate widely used for construction.
- BRL 0801 / 0802 — process certifications for joinery.
How to verify in 5 minutes
Go to the trade body's website directly (do not click the logo on the company's page — links can mislead). Search their register by company name or postcode. If the company is not listed, the logo is not valid for them today, even if it once was.