Slab size vs shed plans

I've got a raised concrete slab 8m x 3m and need to send plans to a "kit" shed supplier.
I want the cladding to overhang the edges of the slab. (not sit on top, like the old shed)
The finished shed should be two thicknesses of colourbond bigger than the slab, each way.

If I supply my 8x3 plans, will they assume this is the outside of the frame OR the cladding?
Do I need to re-label the plans to be 8.05m x 3.05m (@25mm/sheet guesstimation)
If I explain my concern to the supplier, will I look like a complete moron?

No you won't look a moron just someone who is careful.

The real morons are those that assume that everything is going to be OK without checking.

Ask the kit maker whether their design is a
1. sit-on-slab, or
2.hang-over-the-edge style.

If it is Type 1 , you then need to specify the length and width of the structure.
If it is Type 2 , just give them the slab measurements. By the way, you can shorten or lengthen the cladding dimensions when you assemble by manipulating the colorbond sheet over laps. So even if you are a 20-30mm out, it can still be corrected.

After spending a day doing the circuit of steel shed suppliers, I am happy to say that they definitely DO NOT count the cladding into the measurement and they were generally happy with my plans.

That seems to be the only commom factor between them.
One wants $60 extra for a sliding door instead of a roller. Another wants $600 extra.
One says a skillion roof is hard and expensive. The other says it's easy and cheap.
One makes all sheds to an individual plan. Most will alter standard plans without problem. One was insulted at the concept of altering the designs in his pretty brochure.
They all have different ideas of the local DA regs and/or if a DA was required.

Topline Kearsley (agent for Fair Dinkum) ticked MOST of the boxes, so I might take the plunge tomorrow.