against. It is hoped these transitional standards will encourage home builders to start implementing higher standards in advance of the changed requirements. The four performance metrics are as follows: 1. primary energy target; 2. CO2 emission target; 3. householder affordability rating; and 4. minimum standards for fabric and fixed building services. Evidently, the performance metrics are closely linked. Energy efficiency, for instance, lowers CO2 emissions, while increased fabric standards reduces the amount of energy required to keep homes warm. Importantly, however, the energy target is distinct from the CO2 emissions target. This distinction was included to acknowledge that CO2 and energy efficiency are not the same thing, despite being related. This will be particularly evident going forward; overtime CO2 emissions will become less relevant as the UK moves towards decarbonisation. Two options of target CO2 emissions reduction are being considered going forward. The government looks at setting the standard at either (a) 20% reduction in emissions, or (b) 31% reduction in emissions. The latter option, which is preferable, could be achieved by installing carbon-saving technology and improving fabric standards. It is stated, in fact, that the Standard will set very high fabric standards. This will involve: 1. triple glazing; and 2. standards which significantly reduce heat loss for: a. walls, b. floors, and c. roofs. One criticism of the consultation is that it does not propose to stop the use of gas, LPG, oil or solid mineral fuels in building new homes. This contradicts an announcement in March this year by the Chancellor: that the Standard would be introduced “mandating the end of fossil-fuel heating systems in all new houses.” There will be significant costs for home builders in complying with the transitional standards. To minimise the increase in these costs, there is a proposal to prevent local planning authorities from setting higher energy efficiency standards than the Building Regulations set out. The Standard, despite being potentially costly, looks to be very effective in reducing greenhouse emissions — at least those produced by homes. Homes built to the Standard should become net zero as the UK moves to a decarbonised grid. The consultation accepts submissions online and will close on the 10 January 2020. More information can be found here.