Enterprise Ireland
Whole life carbon in construction and the built environment in Ireland report
Marion Jammet, Head of Policy and Advocacy, Irish Green Building Council.

MARION JAMMET, Head of Policy & Advocacy, Irish Green Building Council, explains the key recommendations in Building a Zero Carbon Ireland: A Roadmap to Decarbonise Ireland’s Built Environment across its Whole Life Cycle.

A recent study by the Building in a Climate Emergency (BIACE) Research Lab at UCD, commissioned by the Irish Green Building Council (IGBC), shows that construction and the built environment account for 37% of Ireland’s greenhouse gas emissions, the same as agriculture. Projections to 2030, based on existing policies, are clear: Our sector cannot halve its emissions by then unless urgent actions are taken. These findings are worrying, and the decarbonisation of construction and the built environment will, no doubt, be challenging. However, it also presents an opportunity to improve people’s quality of life while making our sector more competitive and resilient.

Building a zero-carbon Ireland

Building a Zero Carbon Ireland: A Roadmap to Decarbonise Ireland’s Built Environment across its Whole Life Cycle, recently published by the IGBC, details a series of actions to accelerate the transformation of our built environment over the next decade.

Prioritise – Re-use – Reduce

In simple terms, to reach our 2030’s targets, the first step is to prioritise what is being built, re-use (as much as possible) our existing stock, and reduce the carbon intensity of new construction and renovation. Of the 37% of carbon emissions associated with the built environment in Ireland, one-third relates to embodied carbon emissions. These are the emissions associated with quarrying, transporting, and manufacturing building materials, in addition to constructing buildings and infrastructure.

Kingspan PowerPanel

Regulation of embodied carbon emissions

Unlike a growing number of European countries, embodied carbon emissions remain unregulated in Ireland. Without addressing them, it will simply be impossible for our sector to halve its emissions by 2030. The carbon modelling report shows that the Nearly Zero Energy Building (NZEB) standard and the implementation of the National Retrofit Plan should lead to a significant decrease in operational carbon emissions (ie, the emissions associated with the energy we use to heat, cool, and light buildings), but this will be negated by a significant rise in embodied carbon emissions due to an increase in infrastructure and homes being constructed.

Embodied carbon emissions are influenced by the total volume of construction and the carbon intensity per unit of construction. The roadmap advocates for prioritisation of what is being built to meet citizens’ housing, health, sustainable transport, economic and educational needs without blowing our carbon budget. More specifically, there is an urgent need to measure the whole-life carbon impact of all projects to be built under the National Development Plan. With household sizes decreasing, the mix of home sizes also needs to be re-evaluated. With a sufficiency of three- and four-bedroom homes likely already within the existing stock, integration of one- and two-bedroom homes into neighbourhoods could enable downsizing, freeing up family homes for those who need them. This would allow more homes to be built for less cost in manpower, materials, and carbon emissions. Our existing stock must also be better used, with a significant share of new homes needed to be sourced from the high level of vacant and under-used spaces, including above retail premises in our village, town and city centres.

This is key as embodied carbon of a deep retrofit is estimated to have approximately 25% of the carbon intensity of a new build.

Finally, the new homes we build must be highly energy efficient and deliver as per design, with the construction process itself being low carbon. A reduction in carbon intensity per square metre can initially be achieved by leaner design (ie, using commonly available materials, but using less by optimising building form factor, efficient structural design, and material use). But significant innovation is also needed to rapidly decarbonise the materials themselves and/or develop alternative low-carbon materials.

“To reach our 2030’s targets, the first step is to prioritise what is being built, re-use (as much as possible) our existing stock, and reduce the carbon intensity of new construction and renovation.”


Supporting policies

Policy and regulatory changes, as well as financial support, will be needed to deliver on these actions. As what is not measured cannot be improved, measurement of whole-life carbon for larger buildings should be mandated. This, introduced alongside a planned schedule of limits per square metre – getting stricter over time, will give the industry long-term certainty and support the drive for innovation.

Anecdotal evidence from our colleagues in France and the Netherlands suggests that embodied carbon regulation has led to innovation in low-carbon materials, including biobased materials in these markets. Technical guidance documents (TGDs) will need to be reviewed to support this transition. This includes TGDs K and M to accelerate the conversion of existing vacant space, and TGD B to address the limits placed on timber construction above three stories. The application of articles 27 and 28 of the EU Waste Framework Directive in Ireland must be urgently reviewed to enable the re-use of materials. Ireland, with a large agricultural sector, has a strategic interest to identify, encourage, and develop local low-carbon bio-based solutions from agriculture and forestry. This requires reviewing licensing for industrial hemp production and strategic government investment or risk sharing to create large export-orientated bio-based construction industries.

Finally, delivering on Ireland’s renovation targets will require further financial and technical support to make retrofits more affordable and accessible.

A collaborative approach

While critical, none of these policy changes can succeed without strong support and collaboration across the industry. Designers, manufacturers and suppliers, developers and contractors must all work together to accelerate Ireland’s transition to a zero-carbon built environment.

Your journey to net zero

To facilitate the implementation of the Roadmap, sector-specific strategies were developed in close cooperation with industry. These include simple steps that building owners, investors, developers, product manufacturers and suppliers, planners, design professionals, contractors and facility managers can take to accelerate their decarbonisation journey.

For instance, developers can drive the transition to zero-carbon buildings by the targets they set for the design team. The first step is to ensure all new projects are fossil-free and require a design-for-performance approach. Targets for whole-life carbon should be set to gradually reach net-zero carbon. This requires investing in innovation to ensure at least a certain percentage of new buildings integrate innovative construction products and processes.

Key role of product manufacturers

Product manufacturers and suppliers are key to the decarbonisation of construction. Materials and products can represent more than 80% of the embodied carbon of a new build. Irish product manufacturers can already receive support from Enterprise Ireland to develop Environmental Product Declarations (EPDs) and strategies to decarbonise the production process. Suppliers should request EPDs from them and international producers or suppliers to increase transparency in the market.

Key role of contractors

Contractors will play a key role in the transition to zero-carbon buildings with the expertise to advise at design stage on new low-carbon forms of construction and processes. They should engage proactively with the design team and subcontractors to propose optimisations of construction and lower-carbon options and drive the adoption of low-carbon modern methods of construction (MMC).

Improving carbon reporting from site activities and developing a strategy for zero-carbon sites is another important step. An inspiring example of the same is the “Olav Vs gate” project in Oslo, as all the machinery used on site – excavators, diggers, and loaders – were electric.

Decarbonisation roadmap

The whole-life carbon in construction and the built environment in Ireland report will inform the development of a roadmap to decarbonise Ireland’s built environment across its entire life cycle. The IGBC is currently developing the roadmap through extensive stakeholder engagement.

An initial set of recommendations was published in November 2021. This highlighted the need to develop a clear pathway and concrete actions to decarbonise the built environment and the construction industry. Preliminary recommendations included publishing a detailed timeline for mandating whole-life carbon assessment and limits through regulation to provide certainty to industry; streamlining building regulations and aligning all relevant policies and fiscal incentives to make adaptation and reuse of existing buildings easier; and mainstreaming innovative procurement approaches to help encourage and develop a low-carbon product sector, services, and supply chain.

As one of the largest contributors to Ireland’s emissions, the built environment has a vital role to play in achieving our emissions reduction targets. It is hoped that this new data will contribute to raising awareness about the urgency of addressing whole-life carbon in the built environment and that the roadmap will act as a blueprint for policy and industry to decarbonise our sector.

About the Building A Zero Carbon Ireland Roadmap

The Building a Zero Carbon Ireland roadmap was developed by the IGBC in close cooperation with over 200 key stakeholders from industry, academia and the public sector as part of #BuildingLife – a programme funded by IKEA and Laudes foundations. Training and tools have been developed by the IGBC to support you in your transition to net zero. These include the Carbon Designer Tool, a simple way to estimate the carbon impact of your project at an early stage of building design, which was developed with support from the EPA and the LDA.


The Roadmap is available to download at https://www.igbc.ie/building-a-zero-carbon-ireland/

Irish Construction News, Latest, Sustainability