Help to Buy (equity loans). You own 100% of your home, but only have to cover a percentage of the cost initially with your mortgage and deposit (60% in London and 80% elsewhere in the country). You can defer the rest for a while as it’s covered by an equity loan. There’s nothing to pay on the equity loan for a few years, and the scheme you choose will determine whether you pay any interest after this and when you have to pay the loan back.
For more information read article: Exploring Help to Buy and Shared Ownership schemes