Hello and thanks for using Just Answer.
I am Al and am happy to assist you with your enquiry.
Firstly, your friend would need to obtain consent from her Mortgage Lender, as they would need to release their Charge over the land which you are to buy.
Whether they would consent depends on whether the land to be sold would affect their security- ie if youe friend has a large Mortgage and the land to be sold vastly reduces the valuation of the land she is to retian, they are not likely to consent. Conversely, if the land she is to retain is valued at a lot more than what is outstanding uner her Mortggae, they are likely to consent.
Alternatively, the Lender may consent provided your friend pays to her Lender the money she receives from you, thereby reducing her Mortgage.
As regards ***** ***** you certainly would need planning permission as you will be changing the use of the land (formally called "change of use planning permission).
Subject to your friend getting the all clear from her Lender, I would suggest that you have an informal with the planning department to get their view on your plans, before you proceed.
I hope this helps and sets out the legal position.
If so, I would be grateful if you could rate my answer.