I am very biased in this matter as you will see if you haven't already.

This guy is an electrical engineer. I am also an engineer licensed to
practice in New Jersey. We talk the same language even though in
different disciplines. He has 35 years experience in this field. My
experience is not much different. If you ask me to provide
calculations for something I know the answer already I'll dismiss it as
a waste of time. But if I must do it, I will. There are no fewer than
four models similar to my house in the block. I trust his estimation.
Further more, is he providing far larger capacity heating and AC unit
than the previous rwo estimates? All three estimates were in the same
size range. One estimate was by PSEG. Another indication is the size
quoted in the estimates as compared to the current unit and is my
current unit adequate? Except for the less than satisfactory AC on the
second floor which he is providing a solution for we have no
complaints. This is engineering. Not science. Could all three have
made the same mistakes? I can not rule it out but it is not likely.

Call me pigheaded. One thing I am glad I am not in the medical
profession is the defensive medicine and measures they have to put up
in their daily work. Although they probably bring home much fatter
bacon than I. Does experience not count anymore that one has to
document and substantiate every thing he does? Does experience, trust,
relationship and credibility not count in your profession? I can not
say I will enjoy my work if I have to put up defensive medicine
(measures) on a daily basis. No matter the amount of bacon I earn.