What deposit do you need?
You will need a deposit based on the share you are buying, not the full property price. For example, if a home is worth £300,000 and you are buying a 50% share, your mortgage is based on £150,000. A 5% deposit on that share would be £7,500.
Some lenders accept deposits as low as 5% on shared ownership purchases, similar to 95% LTV mortgages, though putting down more will improve the interest rates available to you. Your adviser can help you understand exactly how much you need to save.
Costs beyond the deposit
As well as your deposit you will need to cover solicitor fees, a valuation, and potentially a mortgage arrangement fee. Stamp duty land tax may apply depending on the value of your share and whether you elect to pay in stages or on the full market value upfront.
You should also factor in moving costs, furniture, and an emergency fund. Your adviser will give you a clear breakdown of the total amount you need before you commit.