This policy is well aligned with European Policy, specifically the Energy Performance of Buildings Directive (recast) which requires all new buildings to be nearly Zero Energy Buildings from 2020 (nZEB), as described in Article 2 of the EPBD.
There are three core requirements which must all be met for a home to qualify as zero carbon:
The fabric performance must, at a minimum, comply with the defined standard known as the Fabric Energy Efficiency Standard (FEES) and
Any CO2 emissions that remain after consideration of heating, cooling, fixed lighting and ventilation, must be less than or equal to the Carbon Compliance limit established for zero carbon homes, and
Any remaining CO2 emissions, from regulated energy sources (after requirements 1 and 2 have been met), must be reduced to zero.