Hi @shahryar I'm not entirely sure what you are asking, are you asking how to import materials/constructions from a gbXML file into OpenStudio or are you asking how to specify new materials/constructions in OpenStudio and then apply those to model imported without those objects? If it is the second question this link might help.help:

Hi @shahryar I'm not entirely sure what you are asking, are you asking how to import materials/constructions from a gbXML file into OpenStudio or are you asking how to specify new materials/constructions in OpenStudio and then apply those to model imported without those objects? If it is the second question this link might help:

http://nrel.github.io/OpenStudio-user-documentation/tutorials/creating_your_model/#construction-setshttp://nrel.github.io/OpenStudio-user-documentation/next_steps/creating_your_model/