Enabling design tool

Hi,

Please look at this sentence:
High sustainability factors and lower cost fuels are seen by some as negatively correlated – i.e. high sustainability means expensive. This relationship is changing and the drivers are new biomass approaches which use sustainability as an enabling design tool rather than a barrier to be overcome.

Does the underlined clause mean the new approaches use sustainability as a means to a lower cost? What is enabling design tool?

Thanks in advance!