This looks like another possible get-out route. It may be that some developments should in fact fail if they cannot be viable. Is this policy wording strong enough to prevent big developers avoiding the commitment to zero carbon?

Necessary butit is to be hoped that it will not be used too frequently. Far better a case by cases approach than any attempt to outline possibilities.

States where the nature or location of the site (for instance impact on the significance heritage assets) means that complying with the requirements of this DPD can be demonstrated to result in a development proposal becoming unviable, Policy DM2 of the Local Plan will apply.
We have set out our concerns regarding the viability assessment supporting the DPD in regard to Section 1 specifically. The viability assessment clearly shows that policies of the DPD will have a negative impact on land values for residential development, for the mid-range value price point (E) the appraisal shows a negative impact for medium, large scale housing as well as most of the flatted schemes assessed. This shows that without a reduction in costs in other areas, i.e. the reduction in affordable housing provision in the majority of cases the policies are not viable for residential development.
This suggests that the Council are proposing to introduce local standards that fail to meet the viability tests of the NPPF, and it is inappropriate to rely on Policy NZC2(E) as an alternative to ensuring new policies are not widely unviable, and to a development meeting the required design standards.