Not really sure I'd call the "Hinduja" family wealth "British" although what small % of their wealth they do have in the UK is undoubtedly in property.
There's quite a number of very rich foreigners who economically have very little effect on the UK apart from monopolizing scarce inner city property.
Eyeballing this, only 11 of the top 50 richest people in the UK have property as their source of wealth.