The Central Bank is prepared to review rules that restrict credit unions from helping to fund social housing.
But the regulator for the sector warned that many credit unions are falling below the regulatory standards required.
Register of credit unions at the Central Bank Anne Marie McKiernan was responding to fierce criticism of her office earlier in the week.
Credit union bodies expressed frustration over the failure by regulators and the Government to make changes to allow them to help fund social housing.
Ms McKiernan told the Oireachtas Finance Committee the Central Bank will engage with the sector about changing regulations that could allow for the funding of social housing.
But she said the onus was on the credit unions to ensure that they were investing the money of their members in a "prudent" way.
She said that credit union management had not presented the Central Bank with adequate proposals that met the regulatory compliance standards.
Ms McKiernan said the biggest challenge facing the sector is to figure out how to grow lending in a responsible manner.