sell off rundown house/ renovate then sell/ sell with planning to devlp into flats, which has best net value?

Question

My mother is in financial difficulties and it is unlikely she will be able to maintain a mortgage on a 6 bedroom house with a large garden in a good area in north london, that is rundown, with damp problems, bits coming apart. She need to sell it off, pay off the mortgage then down size and have money left over as a pension. A conservative estimate would be half mil for house, she still has 250,000 in mortgage, which actually doesn't leave her much, in terms of buying a flat and living in london.
The question is, in order to maximise the amount she gets (every penny helps as she does not have other income)
Should we get rid of the house as it is, should we borrow somemore from the mortgage to do some careful renovation and sell it on, although structurally, this maybe more hassle, or should we get planning permission for flats, then sell on with this, as it is in an area that is increasingly been developed into flat? Comments from estate agents/developers welcome!

Answer 1

unless u can do most of the work yourself then its best to let it go . or u could rent rooms to get another income.

Answer 2

You'll need to do a detailed business analysis of all of the options to decide which one will result in the most profit potential. Nobody can give you a cut-and-dried answer here.