I built a 12 x 16 she shed about 18 months ago. I laid 3 or 4 patio blocks level on the ground, then made two 16ft beams be screwing 2x6s or 2x8s together that I laid on top of the blocks. I did use the mobile home hurricane straps with helical anchors to hold the double 2x6 (or 8") beams down. Then I built the floor framing on top ot the beams. I think I notched the beams for the floor joists.
With this arangement nothing except the patio blocks touch the ground, so nothing to rot.
We bought a custom she-shed, extra windows 16X14 at a local company. We had another company come in and level and tamp down the ground. When the shed was delivered one guy built the whole thing in two days.
Set up on what to me looked like stepping stones but they assured me those were manufactured to hold considerably more weight than a regular paver. He doubled stacked them and used maybe 80 pavers or so overall.
They used hurricane cables as our code requires - it is suitable for living in, has AC/Heat and a separate electric box, we insulated it and drywalled it too. Except we never had it plumbed due to costs - we have had friends and family stay and sleepover, but I do wish we had gone ahead with water and plumbing for a toilet and a shower/sink.
The building material is guaranteed not to rot. So far we haven't had any issues - ten plus years in - except with the shingles (3 times and they came to fix it 3 times twice under their guaranty and the last time out of courtesy - no charge) haven't had any problems since.
In retrospect - if you spent the money on a decent shed - go the extra mile and make it multi-functional for what you really want to use it for.
I've been thinking I may place an outdoor shower there - it would be great to be able to take quick shower after gardening in this heat and could be functional for anyone staying in the shed too.
A rather cheap project/option for our climate.
For us it has been a lifesaver - it serves so many different functions, money well spent. I took pics of the built they may still be on the hard drive if you want to see - I'll try to find them.