Uf-values for thermal break metal profiles of window systems The present ift Guideline was prepared in collaboration with the aforementioned partners The Guideline refers to a series of European standards describing the thermal performance of building elements. The present Guideline reproduces the current state of research and investigation and is based on the relevant European standards. The Guideline is subject to revision and/or inclusion of additional methods or procedures in the case of amendments to the relevant European standards, and as necessary from the experience gained from practical application of this Guideline.weiterlesen