Its annual results showed lending rose for the fourth consecutive year to reach £52.2m.
Customer deposits also increased by 3.6% to £142.5m.
The bank said it had "remained resilient" despite continued low interest rates and rising legal and regulatory compliance costs.
ASB, which now holds reserves of just over £16m, recorded a pre-tax profit of £753,000 in 2012.
Jim Armstrong, president of the bank's board of trustees, said: "For the past three years, we have continued to be affected by the same key issues - interest rates continuing at historically low levels, the economic climate and, of course, ongoing regulatory changes.
"In particular, increasing focus on compliance has involved considerable additional costs for ASB, including those borne by the bank in meeting its share of the liabilities for the Financial Services Compensation Scheme incurred by failures during the banking crisis of a number of institutions."
ASB chief executive Jim Lindsay retired recently after serving at the helm for 13 years.
He was succeeded at the beginning of the year by Rod Ashley, former chief executive of Glasgow-based credit union Scotwest.
Mr Ashley said: "As we look to the future, ASB intends to maintain its traditionally cautious approach and stay true to its traditional banking values."
Airdrie Savings Bank (ASB) increased lending by 7.5% last year despite tough economic conditions, the bank has reported.