The zero carbon journey for the built environment

Introduction

Climate change is one of the defining issues of our times. From shifting weather patterns that threaten food production to rising sea levels that increase the risk of catastrophic flooding, the adverse effects of climate change will increase without an effective global response.

The UN Intergovernmental Panel on Climate Change (the IPPC) produced a special report in 2018 which highlights that a number of climate change impacts could be avoided by limiting global warming to 1.5ºC compared to 2ºC or more. The report found that limiting global warming to 1.5°C would require "rapid and far-reaching" transitions in land, energy, industry, building, transport, and cities. The report states that global net human-caused emissions of carbon dioxide (CO2) would need to fall by about 45 per cent from 2010 levels by 2030, reaching "net zero" around 2050.

There is no doubt that the ambitions of the Paris Agreement require a radical reduction in greenhouse gas emissions. In response to this governments around the world have introduced legislation and policy initiatives to tackle climate change supported by a growing recognition by businesses of the importance of environmental, social and governance (ESG) factors.

Here lies the challenge for the built environment. It is estimated that buildings cause 39 per cent of global carbon emission¹ and therefore urgent action is required to improve the sustainability of real estate if we are to have any chance of hitting carbon reduction targets by 2030 and reaching net zero by 2050.

At its most basic "net zero" means only producing carbon emissions during the lifecycle of a building which can be mitigated in equal measure. This will require improvements in the energy efficiency of buildings, the use of greener resources, moving away from fossil fuels to renewable energy making it likely that an element of carbon off-setting will be necessary.

In this article we will look at how technology solutions are delivering sustainability performance through the design, construction, operation and refurbishment of buildings in both the UK and the Australian markets.

Existing zero carbon solutions

Net zero means any emissions would be balanced by schemes to offset an equivalent amount of greenhouse gas from the atmosphere, by, for example, planting trees or using technology such as carbon capture and storage.

A net zero carbon building will primarily be an energy efficient building. Technology will play a key part in delivering an ultra-low energy building. Maximising energy and thermal efficiency will be a key consideration when looking at the specification of the construction materials and the design of the mechanical systems used in the building. It will also be critical to move away from fossil fuels and take advantage of low carbon technologies to supply heating and hot water. However low carbon solutions can be expensive and therefore government policy and regulation should prioritise measures to drive affordability and adoption of existing low carbon technologies and support innovation in new technologies.

Innovative design features will make a building airtight and better insulated. This might include a double skin façade complete with computer controlled vents and triple-glazed windows.

Generating onsite renewable energy will also be a key consideration as well as the general greening of the building by including open green spaces or living green roofs.

Limiting carbon emissions will also have to take into account more sustainable transport solutions for occupants of the building by adapting the building so that it can support the increase in greener transport options. This may mean making provision for more cycle facilities and having electric vehicle charging points.

Having designed and constructed a building to an ultra-low energy specification, it will be just as important to regulate the in-use energy consumption. Technology can be used to monitor real-time conditions throughout the building. Making a building smart begins by linking core systems such as lighting, power meters, water meters, pumps, heating, fire alarms and chiller plants with sensors and cloud based control systems that can manage conditions remotely. At a more advanced level, elevators, access systems and shading can become part of the system.

Sensors are an integral part of smart buildings and play an important role in collecting data to inform decisions about where to allocate resources. All this information is gathered and analysed in real time. This ongoing monitoring allows for automated adjustments that can control conditions throughout an entire building.

Smart buildings generate a large volume of valuable data, allowing sophisticated algorithms to analyse real time data to make operational energy saving decisions. For example the building automation system can learn when to turn the air-conditioning on and off in different zones in the building depending on occupancy rates.

Internet of Things (IoT) devices and other types of smart building technology are already well established for applications such as lighting and HVAC controls, but almost every device with an on-off switch can incorporate IoT in some capacity. IoT applications can be used to monitor air quality, to track occupancy rates and space utilisation but the potential of IoT is huge and it has the ability to monitor and regulate the operation and efficiency of a building.

The result is that smart building strategies can reduce energy costs, improve building operations, support sustainability efforts and enhance decision making.

There is no doubt that action to tackle global warming is a necessity, but it is also clear that improving the sustainability of the buildings can deliver a number of other benefits. Improved energy efficiency means lower operating costs.  

(i) UK perspective

The UK Green Building Council highlighted in its report, Net Zero Carbon Buildings: A Framework Definition that the operation of buildings accounts for around 30 per cent of emissions, mainly from heating, cooling and electricity use².  While for new buildings, the embodied emissions from construction can account for up to half of the carbon impacts associated with the building over its lifecycle³.

The UK became the first major economy in the world to pass into law that the UK will bring all greenhouse gas emissions to net zero by 2050, compared with the previous target of at least 80 per cent reduction from 1990 levels. The UK's 2050 net zero target was recommended by the Committee on Climate Change, the UK's independent climate advisory body.

The UK Green Building Council's framework definition for net zero carbon buildings is designed to provide clarity on how to achieve net zero carbon in the construction and operation of buildings in the UK. The framework sets out two definitions for net zero carbon buildings – one for emissions from the construction process and the other for in-use operational energy.

The 2017 Clean Growth Strategy highlighted that £2.5 billion is planned for investment in the development of low carbon technologies between 2015 and 2021. This includes up to £505 million for the "Energy Innovation Programme"⁴ which aims to accelerate the commercialisation of innovative clean energy technologies and processes into the 2020s and 2030s.

A sustainable building is likely to command a higher value, particularly if it has obtained a recognised certification. For example BREEAM (Building Research Establishment Environmental Assessment Method) is an international green building rating system which certifies an asset's environmental, social and economic sustainability performance, using recognised standards and benchmark criteria. It sets standards for the environmental performance of buildings through the design, specification, construction and operation phases and can be applied to new developments or refurbishment schemes.

There also seems to be a definite correlation between a sustainable building and the health and well-being of the occupants. As we come through the COVID-19 pandemic occupiers will place ever greater importance on the health of the building in terms of air quality, daylighting, and access to open green spaces.

One example of how the technology is being used in practice is the regeneration project in Elephant & Castle in central London which is the product of a partnership between Lendlease and Southwark Council and when completed will be the first Climate Positive development in the UK. It is likely to be one of the most sustainable inner city regeneration projects:

"As well as planting more than 1,200 diverse trees and delivering 11 acres of publicly accessible spaces in Central London, there will be green roofs, green walls and other planting that will help enhance air quality and a focus on rainwater harvesting. The on-site Energy Hub will include a combined heat and power plant (CHP) utilising natural gas, offset by grid-injected biomethane, and will deliver net zero carbon, affordable heat and hot water to residents and businesses across Elephant Park, with the capacity to connect into a further 1,000 homes across Elephant & Castle opportunity area. The new homes will be at least 35 per cent more energy efficient than current regulations require."⁵

(ii) Australian perspective

Similarly to the United Kingdom, Australia's built environment sector is responsible for a significant amount of the nation's total emissions. According to the national Department of Industry, Science, Energy and Resources, Australia's residential and commercial building sector is responsible for 17 per cent of total emissions⁶. This figure represents approximately half of the total electricity emissions generated in Australia.

However, real estate companies and funds based in Australia, and the Oceania region more generally, have been at the forefront of improving the sector's sustainability performance. These companies have substantially outperformed the rest of world in GRESB's (Global Real Estate Sustainability Benchmark) annual Real Estate Assessment for nine consecutive years⁷.

It is perhaps for this reason that the Australian Sustainable Built Environment Council (ASBEC) report, Low Carbon, High Performance, considers that the technology already exists to achieve zero carbon buildings: 

"Market leading Australian property companies have demonstrated the potential for energy performance improvements over the past decade, consistently topping international green building benchmarks with world-leading sustainable buildings."⁸

Examples abound in the Australian context of companies utilising existing technologies to improve the sustainability of the built environment. Some of these efforts, including the approaches taken by market-leaders such as Dexus, Mirvac Group and GPT Group, are summarised in the Net Zero Momentum Tracker report published by ClimateWorks Australia⁹.

One noteworthy example of Australian government bodies partnering with the private sector to achieve sustainable development involves the Carbon Neutral Adelaide project. The project, which commenced in 2015, has seen the local and state governments partner with 164 organisations and invest over A$5 million in sustainable technologies. This has included investigating and supporting energy from waste technologies and installing solar PV in low-income housing¹⁰.

Lendlease Funds Management has shown similar ambition in this space, aiming to ensure A$12.63 billion worth of assets are net zero carbon operationally by 2025. It is seeking to achieve this target through the implementation of energy efficiency programmes, as well as renewable and low carbon energy systems. Additionally, Lendlease Funds Management will continue to use the Green Building Council of Australia (GBCA) Green Star Rating tool to achieve and monitor its projects.

The Green Star Rating is just one of several sustainability rating systems which have been broadly adopted by the Australian built environment sector. The adoption and implementation of technology to enhance the emissions reduction capability of new and existing buildings is set to feature prominently in the next revision of GBCA's Green Star Rating system, to be released in 2020^11.

The future of zero carbon

The World Green Building Council published a new call to action report on achieving net zero embodied carbon by 2050 to address whole life impacts from the built environment. The report seeks cross sector co-ordination to revolutionise the buildings and construction sector towards a net zero future, and tackle embodied carbon emissions, as part of a whole lifecycle approach.

In "Bringing Embodied Carbon Upfront: Co-ordinated action for the building and construction sector to tackle embodied carbon", World GBC has set bold targets that:

• By 2030, all new buildings, infrastructure and renovations will have at least 40 per cent less embodied carbon with significant upfront carbon reduction, and all new buildings are net zero operational carbon.
• By 2050, new buildings, infrastructure and renovations will have net zero embodied carbon, and all buildings, including existing buildings must be net zero operational carbon.

Embodied carbon is the emissions emitted producing the buildings materials, their transport and installation on site as well as their disposal at the end of life. Embodied carbon can be as high as 62 per cent for some buildings so it is important to address embodied carbon alongside energy related emissions.  

Smart buildings continue to evolve and are on their way to becoming fully digitised, not only catering for classical automation areas such as HVAC and lighting but also developing into demand-based agile living and working environments. With the aid of sensor data, IoT systems can map detailed usage patterns of the building, staff and inventory. There has been continuing advancements in data analysis as comprehensive data analytics is necessary to enable decision making to maximise energy efficiency, space utilisation, supply level tracking and demand-based cleaning. Central analytics platforms are being used to provide more insight from all the raw data and therefore enable buildings to actively respond to a dynamic environment instead of simply giving real-time status information updates.

(i) UK perspective

The UK Green Building Council's framework referred to earlier requires a whole life carbon approach which means addressing all impacts associated with the construction, operation and demolition of buildings and infrastructure. Operational carbon is only one aspect of net zero carbon and reducing whole life carbon is the goal.  

Climate change has traditionally focused on reducing carbon emissions from operational energy consumption. One way to measure embodied carbon is to carry out a whole life carbon assessment and the draft London Plan includes a requirement for developments to carry out a WLC assessment. This requirement applies to planning applications which are referred to the Mayor, but WLC assessments are to be encouraged for all major applications. 

The WLC assessment guidance document has been produced for information purposes only. It will be formally consulted on post publication of the London Plan. It explains how to prepare a WLC assessment and how and when to submit it to the GLA. The guidance is for anyone involved in, or with an interest in, developing WLC assessments including planning applicants, developers, designers, energy consultants and local authority officers. 

An example of a whole life carbon approach is the University of East Anglia Enterprise Centre in Norwich. This building demonstrates the use of different, low carbon materials in construction, and the potential for using local materials. The Enterprise Centre was developed and built to the Passivhaus standard. It has improved insulation and air tightness and there are high levels of control on the energy used within the building. The triple-glazed windows and the building's orientation maximise natural light and minimise heat loss. It has also achieved BREEAM Outstanding.

(ii) Australian perspective

The Australian real estate sector has embraced technological innovation to reduce emissions throughout the entire lifecycle of a residential or commercial building. Growing engagement with technologies like blockchain, battery storage and IoT devices, has enabled consumers and corporate customers to monitor energy usage and improve practices accordingly.

Additionally, private and public investment in a variety of sustainable technologies has the potential for substantial emissions reductions in the short and long term.  These technologies are summarised and assessed in the national government's Technology Investment Roadmap discussion paper, released in May 2020¹². This discussion paper assesses developing technologies for the built environment sector against their capacity to reduce emissions, cost and commercial readiness.  

The discussion paper specifically identifies several promising technologies including: heat pumps, thermal storage facilities, the use of low embodied carbon materials and solar photovoltaic (PV) windows or tiles.

These technologies are at various stages of scientific and commercial development. However, the report predicts that most carbon reduction technologies will reach an advanced stage of commercial readiness by 2030. By this point many technologies will be either the subject of market competition, driving technological development, or regarded as bankable assets in the real estate sector.

Exemplifying the potential of these technologies, Frasers Property Australia utilised ground source heat pumps (GHSPs) to adopt geothermal heating and cooling in 800 homes in Blacktown, Western Sydney. The technology has resulted in large reductions in electricity usage from air-conditioning systems. While GHSPs are relatively common in the USA and Europe, they are less often utilised in Australia. This is likely due to Australia's relatively mild winter temperatures. However, the technology has a substantial emissions reduction potential in Australia's colder southern states¹³.

Challenges to reach zero carbon

A net zero carbon building should be one based on in-use, rather than modelled, energy performance. In this way, net zero carbon can be a process which demonstrates that a building's performance is being maintained at net zero carbon.

"Design for compliance" seems to be a short-term objective – compliance with regulations – is achieved without consideration of how the building will actually perform when in use. The consequences of this approach are evident in much of our existing building stock, with operational performance being lower than anticipated at design. The building achieves performance in theory but not in practice.

Operational energy consumption is often categorised into two key components. "Regulated" energy consumption results from controlled, fixed building services including heating and cooling, hot water, ventilation and lighting and "unregulated" energy consumption results from processes such as ICT equipment, lifts, refrigeration systems, cooking equipment and other "small power".

Retrofitting more existing building stock will also be needed in order to reach net zero carbon. One barrier to achieving this is commonly referred to as the "split incentive". This is where the landlord is responsible for the capital expenditure to make the efficiency improvements, but the tenant is the one who is likely to benefit from lower energy bills. Overcoming this barrier through both regulatory and voluntary measures will be key to making progress on this front.

Building regulations should be updated to signpost when verification of in-use energy consumption will become mandatory. We need to be able to compare energy predictions for a building against actual energy measured in-use.

(i) UK perspective

One of the well documented shortcomings of the current Part L of the Building Regulations calculation methodology is its omission of unregulated energy loads¹⁴. Although it can vary considerably by building type, unregulated energy can form up to 50 per cent of total operational energy¹⁵. The lack of consideration of unregulated energy at a regulatory level can lead to drastically different consumption to that estimated at the design stage.

From 1 April 2018 the Energy Efficiency (Private Rented Property) (England and Wales) Regulations 2015 ("MEES Regulations") prevent landlords from granting a new lease of premises unless the Energy Performance Certificate (EPC) has a rating of E or above. From 1 April 2020 landlords of domestic property are prohibited from continuing to let property and this will also apply to commercial property from 1 April 2023.

Working towards net zero carbon means that the minimum standard is likely to rise to an EPC rating of B in the near future in light of the government's recent consultation. However EPCs measure theoretical energy efficiency based on design performance and therefore is not an indicator of operational energy use. If the aim is to drive down energy consumption then it might be more appropriate to use a tool that measures actual energy consumption, for example, by reference to a Display Energy Certificate instead.

In relation to retrofitting, the London Energy Transformation Initiative (LETI) Climate Change Emergency Guide outlines requirements for new buildings and is aimed at developers, landowners, designers, policymakers and the supply chain to help define how to approach carbon reduction in the built environment and set clear Energy Use Intensity (EUI) targets. The guide also suggests areas for regulatory reform including:

• Measuring building performance in terms of energy instead of carbon.
• Setting clear future energy targets for both retrofit and new build from 2020 through to 2030.
• Encouraging local authorities to go beyond statutory building regulations and set energy consumption limits.
• Energy efficiency measures should be prioritised over on-site renewables to ensure robust and cost-effective routes to net zero carbon to ensure robust and cost-effective routes to net zero carbon.

(ii) Australian perspective

The Australian House of Representatives' Standing Committee on Infrastructure, Transport and Cities reported on sustainability transitions in existing cities, acknowledging several shortcomings in the nation's efforts to reduce the carbon emissions of the built environment¹⁶.

Notably, ASBEC and GBCA – both key bodies in the sustainability of Australia's built environment – criticised the National Construction Code (NCC) as outdated. The NCC establishes minimum standards for safety, health, amenity and environmental sustainability in the design, construction or renovation of buildings in Australia. The NCC regulates energy efficiency standards incorporating building materials and utilities.

The NCC has been criticised as failing to adapt to emissions reductions possibilities caused by technological innovations in the building sector. The minimum requirements imposed by the NCC are said to be too low, with the ever-widening gap between NCC standards and best practices enabled by new technologies noted in the inquiry.

A report prepared by ASBEC and ClimateWorks Australia builds on the Low Carbon, High Performance report discussed above and explores opportunities for the NCC to contribute to the decarbonisation of Australia's economy in line with Australia's obligations under the Paris Agreement¹⁷.

The Clean Energy Finance Corporation (CEFC) also highlights a wide range of clean energy technologies that are currently not prescribed by the NCC but are proven, readily available and can be deployed immediately¹⁸.

The Parliamentary inquiry also noted that there is little incentive for companies within the residential property sector to exceed the performance standards set by the NCC. While rating systems such as the GBCA's Green Star are designed to create such incentives, these systems have themselves been subject to criticism in the Australian context.

Recent academic criticism of the ratings systems has focused on the fact that most ratings tools are predictive and do not access a building's actual emissions once it is up and running. Additionally, the criteria against which a development is assessed has been criticised as unjustifiably narrow in failing to consider liveability factors such as access to public amenities¹⁹.

Conclusion

As real estate adapts to the challenge of global climate change, building owners and developers will no doubt be considering solutions that combine leading-edge technology with energy conservation. Ultimately, it seems that technology will continue to play a major part in reducing energy use, fighting climate change and creating better workplaces.

Authors: Thomas Kent (Trainee) and Leanne Mahly (Trainee)

1. UN Environment and International Energy Agency Global Status Report 2017.

2. Committee on Climate Change (2018). Reducing UK emissions – 2018 Progress Report to Parliament.

3. Royal Institution of Chartered Surveyors (RICS) (2017) Whole life carbon assessment for the built environment RICS professional statement, UK.

4. Department for Business, Energy and Industrial Strategy, 2019.

5. Lendlease Elephant Park Regeneration Fact Sheet 2018.

6. Technology Investment Roadmap Discussion Paper.

7. GRESB Real Estate Assessment 2019.

8. Low carbon, high performance.

9. Net Zero Momentum Tracker.

10. Carbon Neutral Adelaide: Status Report.

11. Green Building Council of Australia, A Carbon Positive Roadmap for the built environment.

12. Technology Investment Roadmap discussion paper..

13. Distributed Energy in the Property Sector – Today's Opportunities.

14. Building Zero Carbon – the case for action. UK Green Building Council.

15. CIBSE Journal – Unregulated Energy – Why we should care by Kate Dougherty.

16. Building Up & Moving Out.

17. Built to perform: An industry-led pathway to a zero carbon ready building code.

18. Energy in Buildings: 50 Best Practice Initiatives.

19. Greenwashing the property market: why "green star" ratings don't guarantee more sustainable buildings.