First-time buyers are taking longer to save enough cash to put a deposit on a home, according to National Savings & Investments (NS&I). A typical first-time buyer now takes on average four years and nine months to save a 5% deposit for a property. Last year, it took first-time buyers four and half years to save a deposit. Overall, the average size of a deposit rose to £7,653 in the July to September quarter, a rise of £465 on the same period last year.