521 Seventh Ave Hyder Park NY

Aluminum window ,  double hung design. can this windows to be U value 26. right away answer no.  Aluminum double hung or single hung window in order to achieve this energy code must change the material. it can be wood window with aluminum clad or aluminum with interior wood trim. unfortunately for double hung it is impossible to have wood trim and properly operate. therefore everyone working with Aluminum cladding on wood product.