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
