Cabin

For something that small I would build it myself. Have a concrete foundation put in and then build with stick frame or timber frame on top with an access hatch in the floor that can be locked shut from the inside.

Welcome Dano and greetings from Northern Ontario. You are correct about the building code, a fee standing 10' x 10' building does not require a building permit. However some municipalities still have bylaws that might affect your plans so it best to check. If you happen to be in an unorganized township (not to many of those) you are good to go. If you go this route Denob gave great advice. Although I think a 10' 10" construction could be a little small for five people. If you built a 10' x 10' and then another one, then later join them you might be able to stay within the building code. You might want to look into a container. The price would likely be in the same ballpark and they are not subject to the building code. They may be subject to local bylaws. Again check this out first. I hope that helps.

There are three options I can think of!
-One being stupid pricey, but if I had the cash I would not consider it a waste and all! check it out and place whatever U like on top and no one would know. I would build a deck over it with a removable section to hide the entrance, you don't wanna trap your family in if your building above falls onto your latch door. http://www.youtube.com/watch?v=JJBFuwwYnDc

-Two and one I would go with because of my lower cash flow and hill billy style. I would build your shed or building or deck or what have you, on top of as big as possible water tank as possible, sometime you can get a good deal on them; well at least in my neck of the woods. Have the water tank buried into the ground and have the opening above ground level. If ne one asks it's a septic tank! or perhaps you can think of a better reason. Rain water collection ect.

-Three, dig your hole pour a good strong foundation and walls out of concrete, spray the exterior with rubberised membrain for water proofing, have the walls extend up at least a foot or so above ground level. Into the walls goes metal or wood beams and if possible a slab or metal roof. next place or build your shack onto and your good to go.

Most people agree that being underground is one of your best defensive against sever winds and storms. Always check with a contractor and let them know that you want your structure safe and sounds even if the power fails and having a drop of water in it is unacceptable. They will have all kinds of useful info for you. and maybe if your lucky even some more useful ideas.

Thank you all...I like the tank idea. This would be at a seasonal cottage and the lot is high and dry so I have some options.