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 some of the amendments in the recently launched Home Performance Index Version 3 and outlines key construction sustainability issues that need to be addressed in the year ahead.

Ireland should have the second-strongest rate of population growth in the EU over the coming decades, reaching a population of six million people by 2050. Housing this growing population without blowing our carbon budget presents significant challenges. The new homes we deliver must not only be highly energy efficient but they must also be built and renovated in a low-carbon way and be well-connected to local communities. This requires policy and regulatory changes, innovation and new financing mechanisms to make sustainable living the new norm.

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Towards decarbonised, comfortable, healthy homes

Energy price inflation and concerns about the security of supply have led to a renewed focus on energy efficiency as the “first fuel”.

In 2018, operational carbon emissions from the residential sector accounted for 16% of our national emissions. These are the emissions associated with the energy we use to heat and light our homes. New homes designed and constructed to the current Nearly Zero Energy Building (NZEB) standard should be highly energy efficient. However, post-occupancy data on actual energy use must be gathered to ensure they perform as per designed and any performance gaps can be addressed.

When it comes to tackling operational emissions, the real challenge lies in existing homes. Ireland has one of Europe’s most ambitious energy renovation strategies and targets. This will provide certainty to the industry, but much more is needed to deep retrofit over 50,000 homes a year. Energy renovation must become more accessible and affordable. This requires building capacity in the industry through a greater focus on apprenticeships and by incentivising and facilitating upskilling.

The Build Up Skills Advisor app is a tool developed to make it easier for building professionals and construction workers to identify training courses that suit their needs in a few clicks. Over time, the information collected through the app will be used to develop an Energy Renovation Advisor Register. This, in turn, should make it easier for homeowners to identify building professionals who have upskilled in that area.

Finance is another key element, and climate justice is critical to achieving our climate goals.

While there are existing supports for fuel-poor target households in income poverty, this assistance does not necessarily reach all households that need it. Hence, there is a need to review the SEAI Free Energy Upgrades scheme. Grants cannot be the entire solution, and the introduction of low-interest loans for the able-to-pay market is urgent. Interest-free loans, already available in Scotland, should become a reality here too. These are examples of actions needed to unlock Ireland’s energy renovation potential.

While the topic is complex, large-scale deep renovation is critical in addressing our sector’s emissions.

Rejuvenating our city, town, and village centres

The greenest home is often the one that already exists. This is because there are emissions associated with all life stages of a building, from raw materials extraction and production of construction materials to their demolition.

Embodied carbon emissions already account for 14% of Ireland’s emissions. These are the emissions associated with the manufacturing of building materials and the construction and renovation of buildings. With 400,000 homes to be delivered by 2030, our sector cannot reach its climate targets if embodied carbon emissions are not addressed. These emissions account for approximately 50% of the emissions of a new home across its whole life cycle. They largely happen before the home is occupied and cannot be retrofitted. In terms of scale and in a business-as-usual scenario, the construction of these new homes will be each year equivalent to bringing a new Moneypoint coal-burning power station online.

As highlighted in the IGBC’s roadmap to decarbonise Ireland’s built environment – Building a Zero Carbon Ireland – better use of our existing stock must be a priority. The embodied emissions of a deep retrofit in the residential sector account for an average of just one-quarter of the emissions associated with new builds. As many of these properties are located in city, town and village centres, bringing them back into use should also reduce our fastest-growing source of carbon emissions, transport.

Too often, our village and town centres are blighted with abandoned and underutilised buildings. Research by the Heritage Council shows that groundfloor commercial vacancy rates in towns in Ireland is 18-31%, the upper floors are at circa 80% – both levels unheard of in a European context. Bringing these properties back into use requires regulatory changes and new financing models. It also represents an opportunity to make our city, town, and village centres more vibrant, to enhance air quality and restore the cultural and aesthetic value of these areas.

Healthy, low-carbon homes in vibrant communities

With a growing population, a significant number of new homes and infrastructure must be built by 2030. This represents a challenge as our industry must halve its emissions by then. In simple terms, it means that all new homes must be extremely energy efficient. They must also be located in walkable and well-connected communities. And the construction process itself must be low carbon.

To support this transition, the IGBC recently launched version 3.0 of the Home Performance Index (HPI). The HPI is Ireland’s national certification for quality and sustainability in new residential developments. The certification goes well beyond the BER to address all of the environmental impacts of new homes, such as the production of building materials, impact on ecology, pollution, water consumption and flood risk.

One of the objectives of the update was to align the HPI with the European Union’s Taxonomy for sustainable activities. The Taxonomy outlines the key criteria to be met for an economic activity to be regarded as “green”. The more environmentally friendly a project is, the easier it should then be to obtain funding at a lower interest rate. As per the requirements of the Taxonomy, new homes certified under version 3.0 of the HPI must use 10% less energy than new homes built to the NZEB standard. Life cycle assessment (LCA) and ecology have also become mandatory indicators.

Conducting LCAs is a first step in addressing embodied carbon emissions. These are a factor of both the quantity of materials used and the carbon intensity of those materials. Reduction in these emissions can hence 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 this approach has its limits. It will need to be complemented by the decarbonisation of the materials themselves or the development of alternative low-carbon materials, such as bio-based construction materials.

Transitioning to more sustainable building materials and more compact urban growth should also contribute to better protecting biodiversity. 90% of biodiversity loss can be associated with extraction of materials, with 50% material extraction for use in construction. The IGBC has also estimated that current density recommendations and patterns of development could lead to the urbanisation of a land surface equivalent to a third of County Dublin by 2030.

In 2023, the IGBC will provide more training courses on LCA, launch a full LCA methodology and develop additional case studies. For the first time, we will also launch a webinar series on biodiversity and the built environment to support this transition. Construction companies are also encouraged to visit the “Building a Zero Carbon Ireland” webpage to endorse the roadmap and commit to three sector-specific actions to implement in 2023 to make their work more sustainable.


Further information on the Build Up Skills Advisor app, the Energy Renovation Advisor Register and the “Building a Zero Carbon Ireland” report is available at www.igbc.ie


 Further information on the Home Performance Index certification scheme is available at www.homeperformanceindex.ie


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/

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