remodel/add on advice

Il see if I can set the stage here, just looking for some advice

My wife and I were given land and a house after a death in the family.
This house was built in 1980 its around 1850 square feet, 3 bedroom, two bath, 2 car garage with brick and a metal roof,all on a slab. We have gutted the inside of the house down to the studs, removed the fireplace and chimney. We are wanting to make the garage into our master bedroom and want to add on new build for the bathroom, and add new build for a mud room. By doing this it makes the house around 2800-3000 sqft.

Some questions:
Should I GC out myself? Or hire a GC?
We get free natural gas so Im thinking all gas in the house
The ceilings are 8 foot, How long does a metal roof last on a house? If its time to replace it I could frame to lift the ceilings
I assume using pex is now the way to go on plumbing?
Where can I get blue prints drawn?
Going to move the hvac that is in the closet into the attic, water heater tank will be moved to the new mud room
house will be foam sprayed

Just looking for some advice as its starting to overwhelm me a bit. Any modern advances in plumbing, electric, etc. that I should think about?

Im a one of a kind, but personally I would want nothing to do with a 2800-3000 sqft house.

Leave havac in the closet.

If it were me I'd hire a good General Contractor (with references well checked). He should be able to help with plans also.

No matter what you do, call it a remodel. And don’t advertise your upgrades.

You don’t need permits to “replace”

The Tax Man will stick it to you.

Difficult to answer all the questions...

GC or no GC: how much time do you have? How much experience do you have? Do you have a decent network of subs or labor that you can use? How quick do you want it done? How much of a savings is worth it to you and for your time?

Nothing wrong with going all gas.

Typically metal roofs aren’t replaced just to replace them. The aesthetics go well before the structural integrity starts to fail.

I wouldn’t raise the ceilings. You will be surprised what other work has to be done to gain a foot of ceiling space. If you just do it in say the kitchen and living room, not a bad idea and you don’t need to replace the roof.

Pex is pretty much used in all the homes and remodels that I am aware of.

I would say that some of the biggest advancements is in the technological options available in houses now. Plumbing and electrical are pretty much the same as they have always been...just a lot of accessories that we used to not have.

HVAC would be a big sticking point for me on a house with that layout.

Good luck and feel free to ask if you run into any issues

Your list of questions is enough to suggest you find a GC and let them do it.

Thanks for the comments

I was leaning towards just vaulting in the living area and kitchen if I didn't replace the roof, I was just asking because this is my first metal roof.

I have time to GC it, just don't know if that's what I want to spend my time on being that I have shop, horse arena, pins, fence, etc. that needs repair, and painting.

More than likely will use a GC

Finding a GC to do a remodel around here will be tough. Gathering subs will be too. Kind of a no win situation. txshntr pretty much nailed it all. One suggestion I have is to make sure you have enough power. Probably not a 200 amp service to a house built in the 80's.