Mark McAuley: Ireland must embrace low carbon timber building systems to reduce emissions from construction

We have to transition to a new low carbon-building model fast, for the sake of our future

Building timber-framed houses with the use of the latest technologies can reduce the carbon emissions of our construction industry. Photograph: Getty Images
Building timber-framed houses with the use of the latest technologies can reduce the carbon emissions of our construction industry. Photograph: Getty Images

With the energy crisis at the forefront of people’s consciousness globally, renewable energy and the decarbonisation of building operations is a clear social imperative. In Ireland, the day-to-day running or operational carbon of our buildings currently equates to 24 per cent of our national emissions annually.

However, solving operational carbon is not the silver bullet: it is only a part of the vast challenge that faces us. The traditional methods used to construct our built environment are now being challenged by a rising awareness of climate change, and by the gradual but increasing policy focus on whole life carbon.

Whole life carbon is the combination of the operational and embodied carbon in a building through a 50-year period, which equates to 51 per cent and 49 per cent of a building’s whole life carbon emissions respectively. Ireland’s Climate Action Plan provides a detailed plan for taking decisive action to achieve a 51 per cent reduction in overall greenhouse gas emissions by 2030 and sets us on a path to reach net-zero emissions by no later than 2050.

Ireland’s built environment currently represents 37 per cent of overall annual greenhouse gas emissions with 14 per cent of this being embodied carbon, the carbon required to construct the built environment. These are the emissions associated with the traditional construction methods and materials we currently use. It is recognised that the decarbonisation of our built environment needs to address the wider impact of embodied emissions and to respond, Ireland urgently needs to embrace low-carbon construction methodologies on a meaningful scale.

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Timber has the lowest embodied carbon of any mainstream building material, and acts as an ideal substitute for the more carbon-intensive traditional alternatives

EU regulations for whole life carbon emissions are on the horizon and several member states, including the Netherlands, Denmark, France and Germany have already introduced regulation. The Danish require that all new buildings document their environmental impact over a lifespan of 50 years through a Life Cycle Analysis calculation, and that new buildings above 1,000 sq m must comply with strict carbon targets with maximum levels of carbon dioxide equivalent per square meters, per year allowable. France has mandated that all public buildings must be made from a minimum 50 per cent of wood or similar sustainable materials by 2022.

Timber has the lowest embodied carbon of any mainstream building material, and acts as an ideal substitute for the more carbon-intensive traditional alternatives. Europe has recognised this and has embraced mass timber as one of the most innovative and lowest carbon building systems available on the market.

Mass timber is a construction product comprising layers of timber boards bonded together to form high-performance structural panels, which are then used for walls, floors and roof structures. Commonly referred to as Glulam or CLT, these technologies were developed in the 1990s and are now extensively used throughout Europe for medium and high-rise residential and commercial applications. The tallest buildings now exceed 80 metres or 20 storeys.

The popularity of mass timber has risen as the industry looks to futureproof by using technologies that deliver the lowest carbon footprint but meet the most stringent safety requirements. These systems are prefabricated off-site to stringent quality control procedures, so they can be erected on site much faster. This reduces the project delivery programme, while also producing less on-site waste and environmental pollution.

2022: Forestry sector hails €1.3bn State cash for tree plantingOpens in new window ]

Funding of more than €1.3 billion was recently announced for a new forestry programme to 2027. This represents the single largest ever investment by the State in forestry. Irish wood fibre supply is forecast to double from current levels to 7.9 million m3 by 2035, as significant additional volumes come to the market.

The climate emergency requires forestry to play a more central and innovative role, as global demand for wood and wood-based alternatives increases significantly, thereby raising demand and opportunities for innovative low carbon building solutions to be developed locally.

Using local sustainably-managed forest resources to produce construction timber will deliver more sustainable buildings, supporting the drive to decarbonize and meet Ireland’s climate targets, while also addressing our ambitious housing targets by providing a faster means of delivering homes for our citizens.

It can be observed that the EU’s and our own Government’s environmental policies are rapidly outpacing our building regulations, which provide guidance and define how we can build. The result of this will have significant knock-on repercussions from a social, environmental, and economic perspective, if it is not addressed now.

The climate emergency requires forestry to play a more central and innovative role as global demand for wood and wood-based alternatives increases significantly

Currently, our building regulations limit the use of combustible material to a height of 10 metres or three storeys, with recent proposed amendments raising this limit to 11 metres (also three storeys). This approach significantly inhibits demand for a technology that is being widely adopted above these limits internationally and with it any appetite for investment in local production.

Today, 90 per cent of mass timber worldwide is manufactured in Europe. Why is it that our neighbours, with similar stringent regulations, are embracing this technology and we are not?

The State needs to include a range of measures to facilitate, support and drive the necessary innovations and technology adoptions for timber-based modern methods of construction. A fast-track approach is required to develop more advanced regulations, standards and statutory guidance documents that allow the adoption of low carbon timber building systems whilst ensuring the highest degree of building safety.

Other jurisdictions are already advancing their timber revolution. We now need to transition to a new low-carbon building model fast, for the sake of our future.

Mark McAuley is director of Forest Industries Ireland