FENSA is a government-authorised scheme that monitors building regulation compliance for replacement windows and doors. Each FENSA Approved Installer, from large national brands to small local companies, is assessed regularly by FENSA to ensure its compliance to building regulations is continually maintained.


FENSA’s mission is to improve window and door replacements across the UK, by professionalising installers and protecting homeowners.

FENSA makes sure the work complies with building regulations, is energy efficient, and registered with the local council. And verifies that every FENSA Approved Installer’s guarantee is insured.