How to judge whether UPVC doors and windows are damaged

Observe the surfaces of doors and windows for obvious scratches, cracks or discoloration.
Check whether the corners of doors and windows are intact and whether there are any signs of impact or damage.
Pay attention to check whether the sealing strips of doors and windows are intact and whether they are falling off or aging.
Hardware inspection:
Shake the door and window handles to check whether they are firm and whether they are loose or wobbly.
Open and close doors and windows to see if they work smoothly and if there are any lags or abnormal noises.
Check whether the locks of doors and windows can be locked normally and whether they are loose or ineffective.
Functional check:
Check the sealing performance of doors and windows and observe whether there are obvious gaps or air leakage when closed.
For sliding doors and windows, check whether the slide rails are clean and smooth, and whether they are stuck or blocked.
Check the sound insulation effect of doors and windows, and listen to see if the outside sound is significantly reduced after closing the doors and windows.
Safety performance check:
For doors and windows with glass sections, check that the glass is intact and free of cracks or scratches.
Check the anti-theft performance of doors and windows, and observe whether the locks are strong and whether they can be pried.
Use environment check:
Consider the environmental factors where the doors and windows are located, such as whether they are frequently exposed to rain, sand, dust, etc. These factors may accelerate the aging or damage of the doors and windows.