*RATIONEL- FORMA & FORMAPLUS* Corresponding with the AURA and AURAPLUS design, the Rationel FORMA profile, made from solid timber. FORMAPLUS comes with an external aluminum cladding and no compromise on the solid timber internally. The Rationel FORMA and FORMAPLUS are designed to complement British architecture. Beautifully designed, these styles bring the traditional and classic look into the modern-day. Both designs are available with or without glazing bars to aline with your preference.