With a persistent housing crisis and big targets to finally get to grips with the problem, the Irish construction sector will undergo a lot of change in coming years.
In addition, there will be a shift to provide green buildings not as a nice-to-have, but they will be required under increasingly demanding EU directives.
“We need to move from recycling and recovery to prevention and reuse,” says Pat Barry, chief executive of the Irish Green Building Council (IGBC). He was speaking at the launch of Building a Circular Ireland, the council’s roadmap for a resource-efficient circular built environment.
The ambitious document sets out several strategic frameworks and initiatives to transform Ireland’s linear economic model of “take-make-waste” to a more circular one where materials are reused and buildings are designed for adaptability.
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More than 29 per cent of global biodiversity loss is due to the extraction and processing of natural resources for construction.
And in Ireland, construction and the built environment are responsible for 37 per cent of our national emissions – 23 per cent of which is operational carbon – generated during the operational phase (ie, heating, cooling, lighting of buildings) – and 14 per cent of which is embodied carbon, which includes the emissions from building materials and during construction processes (extraction, manufacturing, transportation, installation and demolition).
It is this embodied carbon – and the 8.3 million tonnes of construction and demolition waste generated annually – that needs to be reduced to put our construction industry on a more sustainable footing.
“It’s about the reuse of buildings and more intense use of our schools, homes and offices. It’s about designing for adaptability and disassembly and optimising material use,” Barry says.
The roadmap also calls for better planning and a mix of house types and sizes because more compact developments reduce the carbon intensity of buildings and infrastructure.
For instance, greenfield sites, which have not been previously built on, require 32 per cent more embodied carbon than brownfield sites – that is, previously developed sites.
Tackling vacancy, dereliction and demolition of existing buildings is another priority, as the often quoted maxim states “the most sustainable building is the one that already exists”.
The IGBC also point out many of the three- and four-bedroom homes within the existing housing stock are under-occupied, with 67 per cent of people in Ireland and 88 per cent of those over 65 living in under-occupied homes. This is double the European average and the third highest in Europe.
One solution to tackling under-occupancy of larger homes, according to the IGBC, would be to integrate one and two-bedroom homes into neighbourhoods to enable downsizing so that larger homes could be freed up for those who need them.
“The transition to more compact forms of development, such as apartments and terraced homes, would allow more homes to be built for less cost in manpower, materials, operational energy and carbon emissions,” the report states.
Some more recent urban developments are already embracing these more dense mixed accommodation styles, but arguably many more are needed – ideally in refurbished existing buildings.
The background to all of this is the revised European Energy Performance of Buildings Directive, which will require member states to count embodied carbon in all new buildings by 2030. Member states must publish a roadmap with targets on how to reduce emissions from buildings by 2027.
But there are several stumbling blocks along the way before many of the visionary goals in the IGBC’s new document can be achieved. The first of these is the current Irish building regulations, which prevent the use of combustible construction timber in floors of buildings higher than 10m (three storeys).
The use of timber in taller buildings is one valuable way to reduce embodied carbon. The Timber in Construction Working Group was formed in 2023 to address some of the cultural and regulatory issues which is preventing the use of timber in mid to high-rise buildings in Ireland.
Current fire safety regulations are one barrier, insufficient training in the use of timber in construction is another. Yet in many other European countries, mass-engineered timber is highly regarded as a building material and timber-framed buildings are allowed up to 80m (24 storeys).
Another issue is that the reuse of materials from buildings that are to be demolished is not yet the norm in Ireland.
More than 97 per cent of the materials flowing through the Irish economy are from virgin sources.
The Environmental Protection Agency’s recent re-categorisation of soil and stone as a byproduct rather than waste is a step in the right direction. Yet, such byproducts can only be used for roads and landscaping rather than in construction. And, there are many more potentially useful demolition materials going to landfill or incineration.
John Casey, construction engineer and founder/managing director of Cora Consulting Engineers, is one of the few operators in the construction industry actively seeking to reuse materials.
“The reuse of steel on the Google Treasury building on Lower Grand Canal Street was the first time steel was reused in Ireland,” Casey explains. And while the company did get re-certification (CE Mark) for the reused steel, he says it was not required as the steel was being reused in the same building from which it was taken.
Casey also reused raised access floor tiles in the redesigned Google building, which saved money for the client. “The fact that the client owned the building and was the sole occupant made it easier. Developers who are renting or selling a building are more wary of how reused materials are perceived,” he adds.
The absence of companies in Ireland that will recertify materials taken from buildings for reuse in other buildings is not helping. The use of so-called secondary materials has become so popular in London that reused raised access floor tiles are more expensive than new ones, according to experts watching circular economy activities elsewhere.
The recertification of secondary/reusable building materials is one of the essential steps to develop a marketplace for such materials. And while the IGBC developed a pilot construction materials exchange (CMEx) digital platform, this is no longer functioning.
“There was a lot of interest in the red granite that we put up on CMEx, but in the longer term, there needs to be more foresight so that materials such as steel beams, concrete blocks and precast concrete floors and timber can be taken off the building and given straight to the customer,” Casey says.
The addition of circular economy statements and pre-demolition audits (now mandatory in London) would allow early material mapping to keep products in circulation at their highest value.
Christian van Maaren operates a successful excess materials exchange in the Netherlands with product passports using QR codes and radio frequency identification tags to give potential buyers instant access to material composition, condition, location, quantity and life cycle of products.
In Ireland, “Loop your Spare” is a new digital platform for the reuse of surplus materials between construction projects. Organisations like the IGBC and others will hope that such a platform can be a model for the construction industry to embrace more sustainable practices.
