There is a ton of information in the archives about the HFGH, just use the search function and you'll need hours to read it all. Yes, people are using them in heavy snow areas. These greenhouses do need to be modified and reinforced. They need special foundations built too. Not good for someone who isn't handy with tools.

Not sure what you are referring to about the government.

What I meant by government is that we will have to be inspected my our city before we can use the green house. I don't know if anyone have any problem with their city ordinances when they put up their greenhouse? If anyone have any advices on passing the city inspection then do you mine sharing them with me?

Permit requirements can vary a LOT depending on where you live. This question doesn't seem to come up often here, so either most people aren't required to have inspections for their 10x12 greenhouses...or, maybe they sort of forget to contact the city.

In my city, no permit (or inspection) is required for a single-story building 120 square feet or less. (They do require a permit for electrical work.) We also paid attention to how close we could put the greenhouse to the property line.

Are you sure your city requires a permit/inspection for a greenhouse this small? Without a permanent (concrete) foundation? If you haven't already, I'd just call the local building permit folks, and find out what is required. The city codes enforcement folks here turned out to be very helpful.

Most city's require a permit for 120sq.ft. or more and while some have complained that the 10x12 HFGH was not a true 10x12 they built it a couple inches short for a good reason.. It is less than the 120 so it don't need a permit.
Check and see if you need a permit for less than 120 sg.ft.
If you don't read up on how to modify it then you won't need to worry about a permit anyway because it won't stand long enough for you to worry about the permits.

Thank you mudhouse for your suggestions!
We have already acquired a permit to install a greenhouse. It is required in our city with no exceptions. I already presented our plans and the dimensions of the greenhouse to the city. As of now we have permission to put up a greenhouse. I just want to know if other people have to go through the same things and can give me some advices.
From reading all of the posts in this forum, i think that we will have to modify the HFGH a lot for it to stand and our plants to survive the winter. I have saved the pages that give the instruction to modify the GH.

I am also in NH and had a greenhouse of very similar design. The frame will not withstand a heavy snow load. Every year I would cover the entire greenhouse with a double layer of plastic which would be inflated. Snow would collapse the plastic film, slide off and then the unit would reinflate. It was also a great way to insulate. Where are you located in NH....? Newton here...