My father has retired recently and is about to dispose of the building that he owned and worked in for the past 30 years - he will use the proceeds to provide some form of pension for his retirement. There has been a lot of capital appreciation since he bought it in the 70s and he will be hit with a CGT bill. As well as his old main office space (currently let to a tenant), the building has 2 flats which he now has let out to strangers - these rents are his main current income. My 2 grandmothers lived rent-free in the flats for about 20 years of the 30 years that he has owned the building (they both died in the past 10 years) - can my father claim some relief from at least part of the CGT on the grounds that the flats were dependents' PPRs? Thanks.