It is Pacific Northwest so lots of rain unfortunately.

You definitely want a hanger for your twin cessna.

Options:

1) Build your own if the airport authority will let you. A good option if
space is tight since you will eventually be able to sub-lease or sell the
hanger. Cost might be, what? $50/ft sq?

2) Check around with the airport bums, err... regulars. When hanger space is
tight, people acquire and hang onto their hangers like new york apartments.
With a little "bonus" you might be able to convince some guy to move his
boat or C150 out of that twin hanger and let you use it.

The problem with hanger space is it's not allocated according to supply and
demand. When hanger space is created and administered by a goverment agency
it is basically free, but you can't get any. Just like the old Soviet
system.

Now before you all start yelling about how expensive your hanger space is,
think about the square footage and compare that with the price you'd pay for
a storage unit of that size.