We put down the deposit for a top floor tenement flat in Glasgow for our then 18 year old daughter when she went to Glasgow University. The mortgage was in her name, with us as guarantors. She quickly acquired a flat mate whose rent covered the mortgage, her Dad, over time, renovated the flat and when younger Daughter spent a year at college in Glasgow she lived there too. DD2 then moved to Newcastle for Uni and again we paid the deposit and her flat mate's rent covered the mortgage payments. When DD2 returned to Glasgow to work she lost money on the sale of her flat, but her sister, whose flat had soared in value, remortgaged and gave her sister enough for the deposit on a flat in Glasgow. A few years passed, both DDs had good jobs and partners, the Glasgow flats were sold at a big profit, which enabled them both to buy substantial homes, locally to us. DH and I had recently retired, so were in a perfect position to help renovate their new homes and to be on hand for child minding the 3 DGC who arrived over the next few years.
We did have a vague plan underpinning all this but were greatly helped by the rise in value of Glasgow tenement flats.