Construction loan question

What is the name of your state? CT

Hi. I own my home and am planning to get all new windows and siding from a reputable company. They do the financing through GE. I received some paperwork in the mail and it included a good faith estimate. It also said that it is a loan secured by my mortgage.

My question is, is this common? It's not a second mortgage is it? The only other time I've gotten a good faith estimate for anything was for my mortgage. I'm confused and don't want to get into something I'm not sure of. Any information/advice would be very much appreciated.

Thank you.

What did GE say about it when you called them?

I didn't call them, I called my lawyer and my accountant. It is a second mortgage but all is well. Thanks anyway.