Over the course the scheme 29 Building Societies increased their stocks of loans outstanding to homebuyers by £21.1bn, using £14.8bn of funding.
Other lenders meanwhile decreased their stock of loans to support the economy by £10.8bn, even though they drew £27.1bn net from the initial scheme.
Robin Fieth, Chief Executive of the BSA said: “These figures demonstrate that building societies have used the FLS to support lending to a greater extent than other organisations, where the focus appears to have been mainly on obtaining cheap funding.
“22 building societies have signed up for the extension to the FLS. However, they have also broadened the sources of their funding, with an increase in retail savings balances in 2013 of over £7bn.
“Credit conditions more generally have also eased since the FLS was first introduced. Building societies are therefore well placed to continue to lend to aspiring homebuyers even though the draw down period of the initial FLS has now closed.”
