Before you buy any appliance, hardware or fixture, measure several times and never assume that your house is “standard,” especially for “special order” items that are “non-returnable” or not returnable without some penalty. When my pre-drilled front door was installed, I had assumed that the distance between the holes were “standard.” If there isn’t a standard, there certainly should be one. Make sense, doesn’t it. But, when the lock arrived, I had the misfortune of discovering that the holes for the Baldwin Stonegate Lock are 5 1/2 inches apart, but the holes on my door were drilled 5 inches apart. That was the most painful half inch I have ever encountered.