I’m replacing an old Velux skylight and need to know it’s rough opening before I tear it off. It’s over 20 years old and Velux doesn’t have the info. Any help would be appreciated.
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Do you have the model number of the old unit? When mine failed, I called and Velux gave me a replacement model number that was an exact fit. The new unit could have the dimensions you need?
I just took off the interior trim and low and behold the contractor left trim measurements on the inside of the frame. I put a steel ruler under the frame and got the frame thickness. I think I’ve got it. Thanks for the reply.