Whatever happen to the ‘Zero Carbon Homes’ programme?

The UK ‘zero carbon homes’ policy was first announced in 2006 by the then-Labour chancellor Gordon Brown. The initial plan was for all new build houses to be ‘zero emission’ by 2016, with the emphasis heavily on energy saving by good building design and full insulation.  It was something of a maximal demand. In the extreme, fully implemented, it could mean no external energy imports at all, with energy demand minimised and then met entirely by ‘on house’ renewables, presumably mostly solar, backed up by biomass and possible micro wind units where viable. It was specified that ‘off-site renewable contributions can only be used where these are directly supplied to the dwellings by private wire arrangement’ i.e. directly from local sources. The aim was clearly to avoid imports of commercial energy via the grid, even if this was wholly or partly green energy.

However, after objections from house-builders and developers, based in part on the allegedly high cost of meeting the new energy performance rules, the criteria and rules as outlined in the linked Codes for Sustainable Housing were progressively watered down. For example, on the demand side, it was decided to exclude power used for electronic devices and white goods (e.g. fridges) and that logically enough led on to exclude electricity used to power heat pumps. However, that could be a big concession – heating is the major part of domestic energy use. On the supply side, it was decided that imports from some external grid linked renewables sources could after all be used, along with a range of other so called ‘allowable solutions’, including carbon offsetting i.e. buying in carbon credits from projects like tree planting elsewhere.

The original aim of the Zero Carbon Homes policy had been for all the measures to be ‘in’ or ‘on’ house, following the so called ‘Merton rule’, as developed by Merton Council, keen to ensure that building developers did not try to sidestep stringent energy saving rules, for example by relying on imported green power. Views differ on the wisdom of that, especially as applied to individual houses.  It is clearly important for house builders to pay proper attention to energy saving in their house designs and to incorporate in /on house renewables where viable. PV can certainly help and so might solar heating and some other microgen devices e.g. heat pumps in off-gas grid areas. However, getting fully to zero carbon for heat and power that way would be hard and pricey in many locations: to do that, importing some top up green power from more efficient large-scale wind farms in windy sites arguably makes more economic and environmental sense.

The Conservative and Liberal Democrat coalition government’s 2013 consultation on proposed changes to the scheme said ‘the government recognises that it would not be cost-effective at this time, affordable or technically feasible to meet the zero carbon homes standard in all cases solely through measures on the dwelling itself, like fabric insulation, energy efficient services, and/or renewable energy generation measures (e.g. solar panels). Therefore, the government proposes that house builders can achieve the zero carbon standard by mitigating the remaining emissions ‘off-site’, in effect a kind of carbon offsetting or abatement’: https://www.gov.uk/government/consultations/next-steps-to-zero-carbon-homes-allowable-solutions

It offered a three tier approach, in-house efficiency, on/in/near house renewables and bought in extra power.  ‘Requirements for fabric energy efficiency and carbon compliance are to be achieved by measures incorporated within or on the development site, including by direct connection to community energy schemes. They set a minimum threshold for onsite measures’. Note the inclusion of community schemes: it is no longer necessary to do everything in/on one isolated house; ‘connected measures (e.g. a heat network)’ are also accepted for the core approach. Certainly, linking into district heating networks may make more sense than domestic scale micro-CHP in urban areas.

The key point though is that the in/on/near house measures can be topped up with additional off site ‘allowable solutions’, which could involve the house developer ‘contracting with a third party Allowable Solutions provider for them to deliver carbon abatement measures sufficient to meet the house builders’ obligations.’  But it could also involve ‘making a payment which is directed to a fund which then invests in projects which will deliver carbon abatement on their behalf. The payment would be based on a fixed price which would be subject to periodic review’.  A big let out clause! Moreover, it is left to the developer to choose, although the consultation asked whether there should be a prescribed list to provide house-builders with certainty and a clear indication of measures which are ‘allowed’. It pointed out though that this might be inflexible and reduce ‘the ability for new ideas to be brought forward and could stifle innovation’. There could also be definitional problems.  Similarly, for schemes like district heating, only part of which fed housing.

The government did look at the idea of having mandatory scheme under which ‘Local authorities would collect Allowable Solutions payments from development in their area through a local levy and fund Allowable Solutions projects in their locality according to local priorities for carbon abatement’, but (no surprise) decide against recommending it, though local councils would be able to offer allowable solutions to developers. But in its response to the consultation, it accepted most the rest:  https://www.gov.uk/government/consultations/next-steps-to-zero-carbon-homes-allowable-solutions

As an interesting coda to this, in 2014, the Government noted that it had ‘not considered support for carbon capture and storage or nuclear power in the context of allowable solutions. However, the criteria based approach set out in the consultation for identifying appropriate carbon abatement measures would require that measures will need to bring forward additional, verifiable carbon savings at a cost effective price. Given carbon capture and storage, and nuclear power, would have high upfront costs, they would be unlikely to be cost-effective.’ So here we have the government saying that nuclear and CCS are too expensive. http://www.parliament.uk/business/publications/written-questions-answers-statements/written-question/Commons/2014-10-23/211768/

As can be seen, if all these exceptions and allowable options were taken on board, the Zero Carbon Home might really be more like ‘50% carbon’ or less. Clearly it was on the way out, and in 2015, by which time the Conservatives were ruling alone, the zero carbon goal was in effect scraped, along with linked plans for new building regulations. The announcement on this was made as part of a government report, ‘Fixing the foundations: Creating a more prosperous nation’, which said the scrapping of the two regulations was designed to ‘reduce net regulations on housebuilders’. That was not well received by environmental groups: https://www.theguardian.com/environment/2015/jul/10/uk-scraps-zero-carbon-home-target There was an attempt (via the House of Lords) to repeal the move, but that failed. A Department of Communities and Local Government spokesman said: ‘We are already building some of the most energy efficient homes in the world. Our current standards are tough and already have the full support of the industry. Our aim is to speed up house building and not add extra costs and bureaucracy. We do not need extra legislation as existing legislation is already in place to allow energy performance standards to be set in Building Regulations.’ https://www.architectsjournal.co.uk/news/zero-carbon-homes-policy-scrapped-again/10006475.article

The basic Code system has been retained and is still valuable. However, the language used has begun to change to ‘Low Carbon Houses’, and the fully zero carbon concept seems to have slid out of focus.  Some might say that was sensible. It had been very ambitious, certainly when initially proposed, and 2016 was arguably unrealistic for a ‘zero’ target date. But the effective removal, or at least softening, of tough criteria for building emissions is arguably not something to be celebrated.

This and the previous post are edited from the coverage of UK energy policy in Dave Elliott’s latest book: ‘Renewable energy in the UK: past, present and future’ Palgrave:  www.palgrave.com/gb/book/9783030047641