After an unexpected drop in August, housing finance activity was up strongly in September. Housing finance data published by the Australian Bureau of Statistics yesterday shows the biggest month-on-month increase in activity over the past year.The number of housing finance commitments to owner-occupiers rose 4.4 per cent in September. The value of these loans rose 5.3 per cent (in seasonally adjusted terms).The value of all housing finance commitments (to owner-occupiers and investors) also rose 5.3 per cent. Lenders committed a total of A$25.1 billion in September.Looking longer term, the value of all housing finance commitments was up by 16.9 per cent over the year to September.Commonwealth Bank noted last week that lower interest rates were supporting strong growth in new lending activity, but this was offset by a higher level of loan repayments.The proportion of first-home buyers in the market fell from 13.7 per cent in August to 12.5 per cent in September. First-home buyer participation in the market has fallen from 19.3 per cent in September last year.