This CPD, sponsored by Glen Dimplex Heating & Ventilation, explains the potential impact on heating and ventilation schemes of the Climate Change Committee’s latest report
The Committee on Climate Change (CCC) assesses the UK’s progress towards hitting its emissions-based targets, such as net zero by 2050. In its latest document, published in June this year, the committee highlights the areas the construction sector will need to address in order to construct – and retrofit – homes and other buildings so they use more efficient, environmentally friendly sources of energy. In particular, the CCC writes in its report that it supports the electrification of heat in residential developments, and hydrogen in more industrial circumstances.
Challenges face the UK construction industry around climate change, just as the issue affects wider society. This CPD will look at the committee’s assessment of future energy usage in buildings, how the sector can respond in the face of a changing climate, and how it can prepare for the likely changes to HVAC specifications that will result from the committee’s findings.
How is the UK progressing with its emissions targets?
According to the CCC, the UK’s territorial emissions fell by 28% between 2008 and 2018, with projections suggesting a further 2% to 13% decline during 2020, dependent on the last six months of this year.
Currently, the UK is not expected to meet future carbon budgets or the overall net zero 2050 challenge, both of which it is legally obligated to achieve.
Evidence shows that the lockdown measures resulted in substantial reductions in energy use and emissions, and it is clear the construction sector has made progress in cutting emissions, thanks to changes in regulations and increased industry awareness. Most of this change has come through the adoption of lower-carbon technologies, such as hot water heat pumps, and making use of the decarbonisation of the electrical grid.
But this change was led by the decarbonisation of the power sector rather than a mass change to housing. The power industry went from the highest-emitting sector at the start of the decade to the fourth-highest in 2019. As it decreases further, designers will see increasing benefits from applying electrical solutions to their designs, such as heat pumps and direct-acting panel heaters.
The CCC believes, however, that the building sector on the whole has not decarbonised quickly enough, remaining relativity flat over the second half of the decade.
It is clear that the CCC’s latest update has been listened to, influencing the chancellor’s recent Summer Economic Update and the decision to target a green recovery as the country emerges from the covid-19 crisis.
The government is also likely to heed the CCC’s warning that buildings, which accounted for 18% of all emissions in the UK in 2019, need to decarbonise at a much faster rate. The need to act on this will probably be reflected in the upcoming update to Part L and Part F of the Building Regulations.
The CCC’s report acknowledges that measures need to be taken to recover from the impact of covid-19. But it is also explicit that action should be strongly complementary to the UK’s climate goals and avoid locking in carbon-intensive practices. It says the government needs to go further than the rather piecemeal schemes announced so far.
This is likely to lead to stricter environmental targets in the upcoming changes to Part L and Part F, as the government needs to do more to keep the UK on track towards meeting its emissions targets and be seen to be acting on the CCC’s guidance.
By 2025, it is expected that the policies will be in place for a transition to net zero, with almost all new purchases, such as cars and heating systems, having to be zero carbon by 2030/35.
Incentives and financial returns
According to the CCC report, low-carbon investments have performed better than high-carbon ones since 2008. Within new and existing developments, this has been due to factors such as financial incentives and grants, including the Domestic and Non-domestic Renewable Heat Incentive (RHI), and increased consumer demand for environmentally friendly homes.
In many cases, low-carbon technologies can cost the same as or even less than traditional high-carbon alternatives, while offering a price premium upon market value – for example, the application of low-temperature networks and in-apartment heat pumps to communal apartment schemes in place of the typical high temperature loop and heat interface unit (HIU).
One of the CCC’s proposals to ensure a low-carbon economy is greater use of carbon taxes. The Carbon Offset Fund, applied to new developments in London, is the scheme most people associate with the idea of a carbon tax; it requires developers to pay a set fee per tonne of carbon produced by a building.
There is also the EU Emissions Trading System, which applies only to permit holders of stationary installations such as large industrial sites, power generators and certain public and hospital buildings, but this would need replacing after the UK leaves the EU at the end of 2020. Until more details are provided on this proposal it is unknown what the future of carbon tax may be in the UK and whether this be the wider application of London’s model, or an increase in scope of who needs to be a permit holder post-Brexit.
Reaching the 2050 target will require all consumed energy to be zero-carbon and come from low-carbon sources, which the CCC sees as being electricity, hydrogen and hot water in heat networks, fed into by renewable and nuclear sources, alongside bioenergy and fossil fuels where combined with carbon capture and storage.
Where viable, electrification and district heating schemes are seen as the primary route to zero-carbon heating systems, with a possible supplementary regionalised role for hydrogen to help manage peak demand. Fossil fuels are no supported in the long term. Consequently, the UK must move away from using natural gas, and a strategy needs to be published on dealing with the existing gas grid.
The energy white paper due later this year will highlight this strategy to ensure the UK moves towards using zero-carbon energy with resilient and flexible infrastructure during the 2020s and 2030s.
Both the CCC and the UK government see the electrification of heating and hot water as the main route to decarbonising buildings. The rapid decarbonisation of the electricity grid is leading to the increased specification of electrification and district heating schemes in both new and existing buildings, which is only set to increase further with the update to Part L and Part F.
The CCC urges ministers to take advantage of the reduced cost in renewable generation and to continue to use the contract-for-difference auction mechanism to decarbonise the electrical grid to reach an emissions intensity of 50g CO2 by 2030, including 40GW of offshore wind. This would allow for the increased demand from low-carbon heat, supporting the specification of electrical solutions such as panel heaters, heat pumps and high heat-retention storage heating in the lead-up to 2030.
The CCC sees heat networks as a method of providing heating and hot water services to buildings in areas where population density is particularly high. The committee has called on the government to manage demand risk and unlock investment through zoning and concession arrangements.
Within apartment developments, the UK is seeing a rise in the use of communal heat networks to comply with Building Regulations, while meeting local requirements such as tougher regional carbon targets or the need to facilitate future connection to a district heat network.
Limitations and alternatives
The CCC is clear that the use of natural gas cannot play a part in any energy future. In its June report the committee even suggests that bail-outs for the oil and gas sector should only be given where they support transition to net zero, which would be difficult to do using high-carbon energy sources.
This means that for existing homes the future of gas-based technologies is likely to be based on low-carbon fuels, such as hydrogen and advanced biofuels including biomethane, as the government looks to introduce green gases to the grid. For new housing developments, changes in regulations are already moving away from fossil fuels, and from 2025 it is expected that no new homes will be connected to the gas grid.
Low-carbon hydrogen is seen by the CCC as critical to achieving net-zero targets, and by 2050 it predicts that UK hydrogen production will need to be comparable to the UK’s current fleet of gas-fired power stations.
The government supports the electrification of heat but has yet to balance the levies placed on electricity which make it more expensive than gas. The CCC has said that addressing this issue is critical to the UK transitioning to low-carbon heating while ensuring that consumers do not pay disproportionately for environmentally friendly homes.
There is additional pressure on the government to address this as upcoming changes to Part L and Part F of the Building Regulations support electric solutions, just as the trend for households entering fuel poverty worsens.
The CCC has also called for the acceleration of plans to develop green mortgages and other financial products that support the take-up of low-carbon heating in instances where it is capital rather than operational costs that create a barrier. The £2bn Green Homes Grant is an example of this for those existing homes in England looking to electrify and insulate.
Heat pumps and hybrid systems
The electrification of heat remains the government’s main route for the decarbonisation of buildings, and heat pumps are likely to play a leading role because of their high efficiencies and ability to provide comfort cooling.
Heat pumps are a tried and tested technology across the EU, with more than 37 million units installed, yet in the UK deployment remains below 30,000 units a year. While changes to the Building Regulations are expected to drive uptake within new developments, the CCC predicts the UK will need to be installing 1.5 million heat pump units a year by early 2030, in order to replace the majority of gas boilers in existing housing stock.
Heat pump technology has innovated beyond the monobloc and split heating and hot water systems that usually spring to mind. New technologies, such as hot water heat pumps and in-apartment heat pumps, can also offer benefits to designers as specification options in this space expand and become more flexible. It is also worth noting that natural gas boilers will not feature in the UK’s net zero 2050 heating infrastructure.
The CCC has commented on how UK water demand has dramatically risen during 2020 compared with the same time last year, with an overall increase of more than 2.2 billion litres. As hot water heat pumps and other water cylinders become specified and the UK moves away from gas combi boilers and instantaneous water production, limiting hot water consumption through the application of stored water will also help to make sure everyone has access to hot water as demand and the population grow.
Addressing the performance gap
A key area the CCC wants to address is closing the performance gap within new dwellings. It sees widespread reporting and testing as a solution, comparing a building’s operational data against its designed performance. This would be an expansion to airtightness testing and aim to ensure that buildings are performing as advertised.
Enforcing this would require an overhaul of the planning process and addressing permitted development rights. The CCC believes this should be outcomes-based – focusing on the performance of homes once built – and more transparent, with effective oversight and sanctions. New policies that would introduce and enforce these practices were proposed in the consultation on Part L of the Building Regulations. Consumers will become increasingly aware of this, and in many instances smart controls will give them the data to assess this for themselves
Future policy proposals
Policy for new homes has already moved forward with the government’s release of its Future Homes Standard consultation. This standard will require the deployment of low-carbon, energy-efficient heating systems from 2025, driving out high-carbon fossil fuel within new homes and requiring them to be built to be zero-carbon.
The CCC has supported this, stating that the policy is long overdue, especially as the nearly two million homes that have been built since the Climate Change Act was passed in 2008 are likely to require expensive retrofits before 2050.
Looking beyond the Future Homes Standard, the CCC is hoping that the Heat and Buildings Strategy, expected later this year, will focus on tackling fuel poverty and housing quality. This includes addressing the cost imbalance between electricity and gas as well as issues such as overheating, poor indoor air quality and water usage, all of which are of growing concern.
The committee is encouraging the government to publish long-term trajectories for energy efficiency measures, including a requirement for all new heating systems to be low-carbon from 2030 in off-gas properties and from 2035 across the rest of the building stock.
With an overheating regulation for new developments currently being prepared for consultation, the CCC believes the danger of overheating in residential developments is likely to feature, especially as heat-related deaths are likely to increase threefold by 2050, as a result of not only global warming but also the urbanisation trend that will see many living in close proximity dwellings and suffering from the urban heat island effect.
This is already being recognised, with studies conducted by BRE and CIBSE showing how building design can mitigate overheating risk. This can be achieved by moving away from high-temperature communal systems, which incur high heat losses, reduce overall efficiencies and require larger plant sizes and raise end user bills, and towards ambient or low-temperature systems. Such moves can significantly help in this area and are already being used as a strategy for developments across the UK.
Existing housing stock and office space
Addressing the decarbonisation of the existing housing stock is a major challenge for the UK. The CCC believes this can be achieved by revising standards and incentivising low-carbon heat through a fabric-first approach.
To drive this new behaviour, the CCC sees many levers that can be applied to the various owners and tenants of the 26 million homes in the UK, including different rates of stamp duty and/or council tax, and a rapid scaling-up of the developing market for green mortgages, home retrofit programmes and widespread local energy planning.
Despite covid-19 there will probably still be a demand for office space, even if this has to be designed for greater ventilation rates with no recirculated air or to include larger spaces to allow for greater social distancing.
In terms of new and existing commercial buildings, the CCC believes that the government should accelerate plans to introduce a scheme based on the Australian National Australian Built Environment Rating System (NABERS) model. In Australia, annual NABERS ratings are legally required for office buildings of 1,000m² or more, with mandatory disclosure of the results at the point of sale or lease.
What would this mean for UK policy?
The government wishes to introduce a NABERS-style scheme to commercial developments as it believes the UK needs to overhaul its compliance and enforcement system to ensure they are outcome-based. It also wants information transparency and a clear audit trail of building use and energy efficiency.
When tied in with new, ambitious standards for the private rented sector, which are expected in the update to Part L and Part F, the government hopes that reporting in-use data after building completion will drive carbon efficiency improvements throughout UK stock and enforce compliance with energy-efficiency targets for existing buildings, such as the Minimum Energy Efficiency Standards.
For HVAC systems, such as heat pumps and fan coils, this will highlight the importance of product testing and the manufacturers’ ability to understand and offer advice on which solutions will make the greatest impact, taking into account up-front cost, performance improvements and lower operational bills.
The Committee on Climate Change’s new report explained
Headed by former environment minister John Selwyn-Gummer, now Lord Debden, the Committee on Climate Change provides independent advice to the government on building a low-carbon economy and preparing for climate change. Every June it publishes a report on the UK’s progress towards its legally binding targets, and what actions need to be taken to ensure future compliance.
Its latest report suggests that immediate changes include:
• Investments in low-carbon and climate-resilient infrastructure
• Support for reskilling, retraining and research for a net-zero, climate-resilient economy
• Upgrades to homes and other buildings ensuring they are fit for the future
• Action to make it easy for people to walk, cycle, and work remotely
• Tree-planting, peatland restoration, green spaces and other green infrastructure.