[NA]Interior door lower edge clearance[NA]

[Let'sgoflying!]

I have been unable to find a standard for this. Looking at a home where a small dog could get beneath the doors. I'm thinking 1" looks about right. Need to measure but I think these are closer to 3".
Any code references?

 

[Stewartb]

A typical door is 79 1/8" to fit into an 80" frame. Providing for 1/8" head clearance that leaves 3/4" undercut. Most of the time that's adequate for flooring but if you use deep carpets the doors will need to be trimmed. Larger undercuts are common when the air balancing is bad and some rooms are hot/cold depending on the heating/cooling requirements. More undercut allows forced air vents to blow easier improving the volume of conditioned air into that room..