My cousin has been staying in Edmonton for the past 15 years. The house he has been staying is actually older than that. It was built by our grandfather. Now, The window and door frames of my house are cracking and he was hoping to replacement of the same. Currently, both windows and doors are wooden made. He is planning to replace the wooden door with steel doors from Edmonton. About the windows, he is hoping to get those remodelled or upgraded to uPVC. He believes those cracks are due to weather change. He asked me if I had any suggestions for the same. Well, I am not sure about this. So, I was hoping if you people could give me ideas or suggestions on the same. Is it okay to go and replace them with uPVC windows?