http://www.learningstrategies.com/forum/ubbthreads.php?ubb=showflat&Number=65960#Post65960

This might help. Be sure to read Shawn's last post on Marie's current practice. I am inclined to say your home is a N2/3 house based on what you have said.

My own practice of whether to take the average reading or the front door reading or the true direction is slightly discretionary and experience-based, so it is a little difficult to share it. However, I will say that based on the degrees you have given, it looks like a smooth changeover of degrees, and I would not suspect that much electromagnetic interference. In that case, use the front door reading. One other thing - why do you get ranges of degrees? Are you taking it at different heights or at different parts of the door? A four degree range is enormous in Feng Shui terms.