System 4500 folding doors

The REHAU System 4500 Bi-Fold Door Design is a premium solution for spaces that need a wide, unobstructed opening. It can be an alternative to hinged and sliding patio doors, but can also be used to accentuate open plan living. Whether for residential or commercial applications, this unique door design allows sash panels to fold to either side, creating a wide opening without any interruption. This versatile door design uses compression seal technology for superior sound, air and water performance.


  • Large glazing capacity of up to 1 3/8 in for improved energy efficiency and acoustical properties.
  • Multiple locking points and compression seals all around the sash perimeter for water tightness, minimal air infiltration, security and good sound insulation.
  • Large reinforcement chambers in the sash for sash sizes as large as 7 ½ ft high and 3 ft wide (up to 175 lbs).
  • High-definition finish for weather and stain resistance and ease of maintenance.