You could make a foundation of pressure treated 2x10s (or 2x6, 2x8 etc) on edge which are attached to the shed floor, with a 2x4 flange on the top edge to secure the shed onto. I wouldn't use bungees, they don't make a good permanent installation. You don't indicate what type of floor you are planning. That could make a difference on anchoring the shed.

If you added a cushion/pillow on the seats, would that bring the height up enough? I can't see adding anything to the bottoms of the legs as this could make them unstable if too much weight were put on the chairs. The only other idea might be to completely re-do the base of the chairs using closet doweling for braces as well as legs. It could be a tedious project, but not too costly. I would look for a fine carpenter finisher to do the job. He may have other alternatives.

How cute!! Be sure to follow the inspector's advice-listen carefully!! Ask LOTS of questions, and listen to your "gut". This could really be a cutie!!! IF all is well. THere are so many possibilites, depending on your buget. We always do necessities then build on that-thus are homes have always looked good; and this keeps our spirits up in between projects. Now a few thoughts: Exteior: The dark red is nice, it can fade-red oxidizes. If you want to go for cottage, the tri color combo is great. Would you consider Lt. Med. BLue, Darker med. Blue and white? For shutters-can you use a simple skill saw? take 2 planks of wood and cut half a heart from each, then with a small space between put the hearts together for a shutter-We did this and it worked great!! Of course you'll need to sand and paint. not sure how well I am at explaining-but does work great. Depending on how much you do with the porch,( more bri-brac), a new white screen door could help. Landscaping is the next biggy; around that foundation, flowering scrubs, ect. Have fun!!

To gain a real idea as to the costs of your proposal, you should probably start with an excavation contractor and get an estimate. You need a licensed professional with experience and appropriate equipment (and insurance!). He/she will be doing a major portion of your work: dirt removal and then reconstruction of your yard and driveway to be sure proper drainage is maintained. Will existing infrastructure (buried utility/phone lines, water and sewer lines, etc.) need to be moved? You'll have to pay for that and that ain't cheap. I believe if I decided to do that at my house, I'd have to hire the owner of the specific line, for example, A.T.&T., to do the work. Advice from a structural engineer would be valuable first to make sure that removal of the dirt will not compromise the integrity of your house's foundation. You'll need someone with construction/basement knowledge to seal the to-be-exposed concrete foundation and to cut new window holes. And someone to install new windows. Then a concrete contractor to rebuild your driveway/sidewalk/other new things you might decide you want. And a landscaper to design/install new plantings. Oh! And you mentioned removal of a large tree. In my area, removal of a large tree costs $2,000. And that's just what's above ground. Will you need roots removed too? Others might know: would advice/permissions be required from your municipality because of the change in the grade of the yard (which may affect runoff both into nearby municipal-owned and privately-owned properties)? Obviously I don't what any of these services would cost you in a major city in Canada.