How does Help to Buy Equity Loan work?
With Help to Buy Equity Loan, you only need a minimum deposit of 5% of the value of your new home. The government lends you an equity loan of up to 20% of the value of your home (15% in Scotland, 40% in London), so you’ll only need a 75% mortgage (80% in Scotland, 55% in London). You will not be charged any loan fees on the equity loan for the first five years of you owning your home.
The Help to Buy Equity Loan scheme has been extended until 2021 through a further £8.6 billion in Government funding
 source: gov.uk