Juan Morillas

– Act now: How contractors can play their part in reducing carbon emissions by decarbonising our buildings

Carbon Emissions
Lenny Antonelli, Membership Engagement Officer, Irish Green Building Council.

LENNY ANTONELLI, Membership Engagement Officer, Irish Green Building Council, sets out practical actions contractors can take immediately to start cutting carbon emissions, as set out in the IGBC’s Building a Zero Carbon Ireland: A Roadmap to Decarbonise Ireland’s Built Environment Across its Whole Life Cycle.

Here’s a surprising fact: Ireland has no unified national plan or target for cutting carbon emissions from the building sector. Yes, we have targets for cutting emissions from residential buildings (40% by 2030) and commercial buildings (45% by the same date), but these relate only to operational energy, the energy used for heating, lighting, and cooling. They don’t consider embodied carbon at all.

But embodied carbon – the carbon associated with the extraction and processing of building materials, their transport to site, and the building’s end-of-life stage – is responsible for 14% of our national emissions (operational emissions are another 23%).

In October 2022, the Irish Green Building Council (IGBC) sought to remedy this when we published ‘Building a Zero Carbon Ireland: A Roadmap to decarbonise Ireland’s Built Environment Across its Whole Life Cycle’. We first commissioned UCD’s Building in a Climate Emergency Research Group to determine the baseline emissions of Ireland’s building stock and infrastructure. Then, we modelled what actions would be needed to cut these emissions by 51% by 2030 (in line with national climate goals).

This modelling showed that the actions outlined in the Climate Action Plan would be insufficient and that this target would only be achieved via a significant cut in the carbon intensity of new construction plus large-scale reuse of vacant dwellings, as well as rethinking carbon-intensive projects and making much more efficient use of built space.

We then developed a roadmap of actions for each player in the built environment value chain – investors, developers, designers, contractors, surveyors – to play their part in hitting the 51% target.

For contractors, the roadmap lists practical actions for cutting carbon emissions that could be taken immediately.

IGBC Roadmap:  Eight immediate Actions contractors can take to cut carbon emissions

Contractors should have a strategy in place to ensure that all site personnel, including subcontractors, are upskilled in low-energy construction. By the end of 2025, all site personnel should be upskilled, and this should be a pre-condition for subcontractors. Thankfully, there is a large and growing ecosystem of training available for construction personnel, from the NZEB Centres of Excellence ( to the huge amount of practical and on-site training delivered by building product suppliers to academic courses on topics such as low-energy design, renovation and project management at further and higher education institutes.

  1. Be aware of whole life carbon (WLC), the EN 15978 standard for measuring WLC in buildings, and to meet or exceed WLC targets set by clients. WLC is the sum of operational and embodied carbon. The IGBC’s short, online ‘Embodied Carbon 101’ course provides a great primer on WLC and its measurement. See
  2. Engage proactively with the design team and subcontractors to propose optimisations of construction and lower carbon options. Collaborate early to eliminate unnecessary use of materials and make more efficient use of built space. The IGBC will organise workshops this autumn to encourage collaboration to cut carbon emissions on building projects. Keep an eye on the IGBC website for more details.
  3. Engage with subcontractors and design teams to drive the adoption of low-carbon MMC. By 2030, all contractors will be delivering low-carbon MMC at scale. Site-based building methods still dominate in Ireland, but MMC – which is encouraged in both the Climate Action Plan and Housing for All strategy – can reduce construction waste by up to 90%, facilitate the use of lower carbon materials, and provide a more controlled environment for the manufacture of highly energy efficient building components.
  4. Drive demand for Environmental Product Declarations (EPDs) by requiring that increasing percentages of products used in new projects have them. A growing number of construction products come with EPDs, which are a standardised way of providing information about the environmental impact of a product, including its global warming potential. By specifying materials with EPDs, you encourage manufacturers to be transparent about their carbon footprint, and to work to reduce it. See to learn more.
  5. Start to measure the carbon footprint of the construction process, share this data and plan to reduce this from 2025. The building life cycle stage A5, which covers the construction process itself, is one for which little good quality data is available. It’s critical that we start to gather this data in order to better understand and limit these emissions. The new Energy Performance of Buildings Directive will require the measurement and disclosure of WLC on larger buildings from 2028.
  6. Develop a roadmap to transition to fossil-fuel-free construction sites by 2035. In September 2019, the world’s first modern zero-emission construction site broke ground in Oslo. The project redesigned two city streets and used electric and battery-operated excavators and wheel loaders. The city is now aiming for all construction sites to have zero emissions by 2030.
  7. By 2025, contractors should have ensured the minimisation of waste on site, collaborating with suppliers on take-back schemes and circular business models, and by 2030 be achieving 95% waste diversion from landfill and incineration. Early planning can dramatically reduce waste from site, while digital tools like Smartwaste and the Construction Waste Portal can also help contractors with this critical goal.
IGBC wants your feedback on the actions you have taken to date

The IGBC would love to hear from contractors about the actions you are taking to reduce WLC and your feedback on our roadmap. We’re also asking contractors to join 167 other industry leaders who have endorsed our roadmap at

The roadmap is ambitious, but we have no choice now but to be ambitious when it comes to cutting carbon. The IGBC is here to help and support our member companies and organisations to decarbonise the built environment through education and training, communities of practice and various working groups.


To learn more or become a member of the Irish Green Building Council, visit www.


Lenny Antonelli is the Membership Engagement Officer with the Irish Green Building Council. His role is to support the building industry with decarbonisation. You can reach him at

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