KWS Windows

KWS Conservatories

KWS Windows and Doors

Gallery + Feedback


Glazing Options








Kömmerling - Test Report

Case Study:


Fifteen years of exposure to the extreme climate and temperature fluctuations of Bernina in Switzerland - the perfect environment to test the longevity of any window installation and the ideal platform to provide solid evidence of the durability of Kömmerling profiles.


The Albergo Ospizio Bernina, situated at a height of 2,309 metres, was fitted in 1976 with Kömmerling PVC-u windows. In 1991 two of the fifteen year-old windows were removed and tested.


The uniqueness of the region, which is continuously exposed to long periods of hard frost, violent storms, an inhospitable climate and increased radiation, provides the perfect opportunity for a thorough examination of the windows durability.


The results of the tests carried out on the windows showed that they were in excellent condition, both visually and technically. The sash rebate seal still functions correctly and has suffered no impairment. The pivoting point, which is subject to the greatest wear, is still fully intact and all the metal components are free of any corrosion.

Many PVC-u profile extrusion companies boast of the quality of their product. This section is dedicated to those organisations that wish to discover the sheer extent of the uncompromising quality of Kömmerling window systems and the evidence to prove it.


One of several case studies undertaken shows that Kömmerling PVC-u profiles do indeed stand the test of time. The below case study provides real-life examples that confirm Kömmerling's position as Europe’s Number 1 for PVC-u window profile.

Test Results:


  • 1966-1996

Test Report NO. E59063199

  • 1969-1984

Test Report NO. 6921185

  • 1969-1986

Test Report NO. 20292/87-1

  • 1976-1991

Test Report NO. 136 066

Quality Test Report

Kömmerling Intro


Quality and Energy