Don't forget that you will have to add fuel every 6 to 10 hours typically. Now if the generator is converted to natural gas, that generator bunker in the back yard looks great. However it would not be so good in the front driveway.
In the driveway is really good for when you have to go out and get more fuel. Carrying fuel to the back yard in the rain would be no fun. I have wondered if it would be easy to add a connector to let the car fuel pump pump fuel from the tank to a generator.
As already mentioned, any enclosure type box can lead to problems for a gas generator. Gasoline generators produce a lot of heat when running and the gas in the gas tank can boil!
I once made a nice wood enclosure (I thought) for my gasoline generator - had a ridge vent, had openings on all side just under the slopped roof and I even installed 2 box fans powered off the generator on 2 sides of the enclosure.
As a test I started the generator and set back to watch it - after about 20 minutes I noticed heat waves coming from the roof and then noticed what looked like fumes also. Quickly shutting the unit down I could tell the gas in the tank had been boiling!