UK Policy on Low Carbon Retrofit
The UK is considered to have one of the oldest housing stocks in the EU and has historically experienced a very low replacement rate, it is further expected that two thirds of the existing stock will still be in existence in 2050.Therefore the importance of decarbonising the extant housing stock can be seen crucial, to the goals of reducing CO2 emissions from the sector.
Energy Efficiency Programmes in the UK
In comparison to revisions of Part L of the building regulations, policy action in the area has been relatively slow and piecemeal. A range of policy initiatives or ‘Policy Mixes’ in the UK have been introduced to stimulate improvments in the energy efficency of the housing stock. This has included a noteable idealogical shift from government funded initiatives such as the Warm Front insulation programme, to supplier obligations and market based intiatives such as the Green Deal.
There is a history of energy efficiency programmes in the UK, with the majority delivered through supplier obligations. provides a detailed review of these, however this paper will focus on the more recent programmes.
Carbon Emissions Reduction Target (CERT)
The Carbon Emissions Reduction Target (CERT) ran from 2008-2012 with the aim of reducing emissions from households, via a range of energy effciency measures. Energy suppliers were obligated to deliver targets in terms of Mt of CO2 mitigated, with a mandated 40% delivered through a ’Prioirity Group’; defined as those in receipt of certain income-related benefits or those over 70 years of age. The intiative will see a lifetime 296.9 Mt of CO2 mitigated.
With the onus on the energy companies to deliver the carbon reductions, the lowest cost (£/kgCO2 ) measures were prioiritised; with the majority of savings delivered through insulation methods (66.2%) and lighting upgrades (17.3%). Of this the vast majority was the relaively ‘low hanging fruit’ of loft insualtion with 6.7 million installtions and cavity wall insulation with 2.5 million installtions, also with 305 million lighting measures, mostly via discounted sales or direct provision to residents of compact flurescet light bulbs.
However these modelled scenarios may have failed to acccount for the ‘temperature take back rebound effects’. Defined as where occupants increase the internal temparature of the dwelling, which on average amount to approximately 20% of savings.