Rationel — aluminium windows and doors
Rationel is a second Danish name working in the same composite territory as VELFAC, with a reputation for particularly strong thermal figures and a restrained, understated visual language. The range appears often in projects where both energy performance and quiet architectural detail carry equal weight.
Product information is published directly by the manufacturer at Rationel's official site. In Stevenage and across Hertfordshire, 5EC holds authorised-supplier status for Rationel.
Articles on Rationel systems
Practical write-ups of the products specified most often in the UK.
Rationel Aluclad: composite windows with strong thermal figures
Rationel Aluclad is a Danish composite window system with a particularly strong thermal specification.
Read the article → 8 July 2026Rationel façade glazing: composite systems scaled up to the elevation
Rationel's façade solutions extend the composite window construction to full-elevation glazing on architect-led homes.
Read the article → 30 July 2026Rationel entrance doors: quiet Scandinavian detailing at the threshold
Rationel's composite entrance doors combine timber and aluminium in a restrained Scandinavian idiom.
Read the article →Other brands in the journal
Continue with the ranges we cover alongside Rationel.
Schüco
German engineering that sets the benchmark for the wider aluminium industry.
Cortizo
Spanish manufacturer with one of the largest extrusion operations in Europe.
Kobbe
Bespoke aluminium entrance doors, engineered to individual specification.
Kubu
Smart lock sensors built into the multi-point locks of aluminium doors and windows.
VELFAC
Danish composite windows and doors — aluminium outside, timber inside.