Re: old dirt basement
For what you're proposing, I don't think there's anything special to do. You're just trying to slightly improve a poor existing space so your boxes don't sit on the dirt. As long as you don't make any structural changes, or attempt to make it livable space, or do any plumbing or electrical work, or change the way that a fire would propagate through the space, you might not even need a permit (think of it as "floor covering") as long as you don't have tattletale neighbors.
I really think that the idea of using this space as a work area is a poor one. After working on a project down there for an hour your back and neck will be complaining.
The "Senior Member" designation under my name doesn't mean I know a lot, it just means I talk a lot.I've been a DIYer since I was 12 (thanks, Dad!). I have read several books on various home improvement topics. I do not have any current code books I can refer to. I was an apprentice plumber for two years.