You need a solicitor. The Deeds should be in your name if you are getting a mortgage and, of course, if your father is happy to sign the property over.
You will pay stamp duty on the market value of the property - but at half the normal rate as you are related parties. Your father may have a CGT liability on the disposal to you.
You can go to a mortgage broker who will advise you on how much you may be able to borrow, or you could go to your own bank or you could approach a number of lenders yourself.
You will need an engineer or architect to certify the works for your lender.
There is quite a lot involved but a trawl through this website would be fruitful.
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