Checking all the financial aspects of it. Extra costs, large increases in maintenance, any other restrictions on the use of the flat (no overnight visitors) and remember that when these flats are sold they developer will a cut of the sales proceeds.
That is assuming you can sell the flat because these flats often sell for less, much, much less than the first resident paid for them and maintenance charges, which can be £1,000 a month or more continue until the flat is sold.
In fact if you go ahead, do not buy a new flat directly from the developer but look at those available on the resale market and check that when your mother dies, if the flat is slow selling you can rent it out, providing the age of the tenant, complies with the leasehold rules.
