Summerhouse - allowing for future replacement floor sheets?

[lct]

Question is about how to lay the floor sheets of a timber summerhouse I am starting to design and whether to 'trap' them below the stud walls.

One thing I don't like with all the designs I see is that the perimeter stud walls are built on top of the floor sheet. In my mind I prefer the future option of being able to remove the complete floor sheets to allow inspection of the insulation and ground below. Plus it helps if I can get the walls and roof up as soon as possible and then fall back on the insulation - could even use some temporary floor sheets during the build where I am sure they will get wet and swap them out at the end.

The disadvantages of the 'internal floor sheets':

• It's probably easy to end up with some gaps between edge of floor sheet and wall.
• The perimeter of the floor is not supported - at least not with 2"x4" stud walls sitting on doubled up 2"x5" perimeter beams. I would either have to add a third perimeter beam on all sides (cost), or nail in some CLS all around between the joists, which is a lot of short pieces.
  
• Harder to drop in solid insulation if using the nailed on edge support.

Sketch below shows what I am thinking. One on the right is the 'traditional' design i see everywhere. On the left is what I am considering. Please tell me why I am wrong and why I should stick with the traditional - I am pretty sure it will be the easiest build.

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