Share 'Zonal Pressure Testing'

I got into a discussion with a college the other day about testing the attic connection to the house. When the house is depressurized to -50pa wrt outside, and the attic wrt house is -49pa, isn’t the attic more “outside” then “inside”? When the house was depressurized to -50pa I also looked at the attic wrt outside, and got just -2pa. My understanding is that if the Blower Door is putting -50pa o…