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Last edited 29 Mar 2016
Allowable solutions for zero carbon buildings
In England, the definition of a zero carbon home was one where CO2 emissions from regulated energy use (space heating, hot water, lighting and ventilation) were limited and mitigated by a combination of three measures:
- Achieving minimum Fabric Energy Efficiency Standards (FEES) based on space heating and cooling.
- Using low and zero carbon technologies and connected heat networks to limit on-site built emissions.
- Where it is not possible to reduce the regulated CO2 emissions to zero using these on-site measures, the remaining carbon emissions can be mitigated through off-site allowable solutions.
Unregulated energy (such as appliances and cooking) was not considered within this definition. So in effect, developers would be required to avoid or mitigate all regulated emissions using a combination of on-site energy efficiency measures (such as insulation and low energy heating systems), on-site zero-carbon technologies (such as solar panels) and then using off-site allowable solutions to deal with any remaining emissions.
What constituted off-site ‘allowable solutions’ was expected to include (See CLG: Open consultation: Next steps to zero carbon homes: allowable solutions):
- The developer improving existing buildings or producing renewable energy off site.
- Making payments to an ‘allowable solutions provider' who could be a local authority provider or a private provider.
- A national carbon abatement fund which invests in CO2 abatement projects, with payments into the fund by means of an agreed fee per kg CO2 to offset emissions.
There was also a question about whether allowable solutions should be taken form a ‘prescribed’ list, or whether any solution should be allowable if it satisfied certain criteria, and whether off-site solutions should be local to the development site.
The occupier might not be directly affected by a developer adopting allowable solutions, but they could find that, with the inclusion of allowable solutions charges, their energy bills were higher than they might have expected from a zero-carbon home.
There was some criticism of this approach, as to a certain extent it separated design from 'zero carbon' and developers could find it easier to adopt allowable solutions rather than meet the carbon compliance standards.
On 8 July 2014, the government published its response to the summary of responses to its consultation on allowable solutions. This confirmed the four approaches to allowable solutions for house builders; abatement on site, their own abatement off site, third party off-site abatement, or payment into a price-capped fund. It also confirmed that a national design framework would be established for the scheme.
In December 2010, the government also confirmed the commitment that all new non-domestic buildings should be zero carbon from 2019. This meant the timeframe for zero carbon non-domestic buildings was three years behind that for zero-carbon homes. Consequently, progress towards defining a zero-carbon standard for non-domestic buildings was similarly behind, and due to the wide range of possible circumstances and possible solutions, this definition was likely to be more complicated than for domestic buildings.
However, on 10 July 2015, the government published ‘Fixing the foundations: creating a more prosperous nation’ a government plan for increasing Britain’s productivity.
Amongst a great number of wide-ranging changes, the report states, 'The government does not intend to proceed with the zero carbon Allowable Solutions carbon offsetting scheme, or the proposed 2016 increase in on-site energy efficiency standards, but will keep energy efficiency standards under review, recognising that existing measures to increase energy efficiency of new buildings should be allowed time to become established.'
This announcement was made with no consultation and came as a surprise to much of the industry.
Paul King, managing director of LendLease Europe, said, “...after almost 10 years of commitment and progress, UK house builders and developers have come a very long way. It is therefore extremely disappointing that the government has today removed a world-leading ambition for all new homes to be zero carbon from 2016.”
However, CIBSE technical director Hywel Davies said it was not a ‘huge surprise’, and the move was welcomed by the Home Builders Federation who suggested that zero-carbon standards would have cost purchasers in the order of £2,500 per home.
 Find out more
 Related articles on Designing Buildings Wiki
- Climate Change Act.
- Code for sustainable homes.
- Community energy network.
- Domestic micro-generation.
- Ecobuild 2016 - Making the business case for large scale retrofit investment.
- Renewable energy.
- Wind turbine.
- Zero Bills Home.
- Zero carbon homes.
- Zero carbon non-domestic buildings.
 External references
- Zero carbon hub, Allowable solutions.
- CLG: Open consultation: Next steps to zero carbon homes: allowable solutions
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