class Q - what is considered reasonable work

[and jen]

Hi - I have a relatively new agricultural barn (completed 2012) partly open to one side. It is used for storage of machinery and hay. The main structure is galvanised steel beams with cladding. In the enclosed part of the barn there is a concrete floor with damp proof membrane. The open part of the barn is gravel - where the machinery is stored. I believe there is a strip foundation between the steel beams - not just boot foundations. I would like to apply for class Q to convert to C3. However I am concerned that the lack of a concrete slab in the open part of the barn would be considered 'not reasonable work' despite there being strip foundations that could be built off. Some people tell me that any works within the footprint of the building are allowed (e.g. install block and beam floor) and others say that this amount of work would be deemed outside of class Q.  What are your thoughts and what would be the best way to proceed ?

Also under class Q would there be an opportunity to add a first floor or would the whole area have to be one floor (slab) and open space to the roof?