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
