Thanks for that Sueelen.
Shomera I have more or less discounted. Whilst theres no questioning the quality, the pricetag is off the mark for me. That said, I will be asking them for a price on the equivalent of the 9x4m botanic living unit just in case.
Looks like planning could very well be an issue. I rang up the local planning office and they said that anything over 25m2 would require planning. Furthermore, she said that it would definitely need planning if I intended to use as living accomodation. 3 of the 4 rooms in the house are rented out and I would move into the chalet and rent the remaining room. I am concerned that they will decline planning if I present it this way?