Modern Methods of Construction (MMC) have become an important part of the government’s strategy to combat the ongoing Irish housing crisis. Adopting MMC is a key part of Pillar 1 of the current housing strategy: Delivering Homes, Building Communities, which was released last year. In this blog, I will evaluate MMC, including TASC’s own contribution, to understand some of its benefits, issues relating to MMC, and whether it’s an effective solution to the housing crisis.
MMC refers to building systems that are manufactured off-site and assembled on-site. It aims to improve consistency, speed and sustainability across a home’s life-cycle. There are 7 categories of MMC that relate to structural systems or labour reduction improvements. The most commonly used categories are 1, 2, 5 and 7:
Category 1: Pre-manufacturing – 3D primary structural systems. These are structures built in factories that are delivered to sites to be installed. This can include a single apartment and a common area space on a block.
Category 2: Pre-manufacturing – 2D primary structural systems. These are flat panels, such as walls, roofs and floors that are built in a factory and installed on-site.
Category 5: Pre-manufacturing – non-structural assemblies and sub-assemblies. These include partition walls, waterproofing or insulation roofing equipment assemblies. These are known as pods.
Category 7: Site process-led labour reduction or productivity assurance improvements. This includes drones, robotics and insulated concrete formwork.
MMC in the Irish context is relatively new. It emerged in significance in 2015 when the Minister for Environment, Alan Kelly, announced the creation of 500 rapid built homes for homeless families. Since then, government housing plans have projected an increased use of MMC in the construction industry. The current plan, Delivering Homes Building Communities 2025-2030, sets the target of at least 25% of all new build social and affordable housing to use MMC.
There are many benefits to MMC for Ireland. One significant benefit relates to the environment. It’s estimated that 37% of Ireland’s carbon emissions come from the building environment. 14% is from the embodied carbon from production, transport, maintenance, repair and disposal. The other 23% comes from the general use of buildings. The use of timber in the construction of housing can reduce the embodied carbon emitted by the sector. Timber can also be used in factories, which allows for the optimisation of products to reduce wastage. Timber frame growth has increased massively since the 20th century. In 1992, the National Standards Authority of Ireland reported that timber frames accounted for 5% of new dwellings. This has now increased to 48% in 2021 and 61% in 2025, showing that timber is a much more widely used material in construction costs. It will be interesting to see if this continues to grow as time goes on.
Since 2025, the Department of Housing, Local Government and Heritage has been tracking companies' usage of MMC, so as time goes on, more data will be available to analyse MMC evolution. MMC is becoming one of the best ways to deliver net-zero solutions to housing. This is because of the increased efficiency in construction and improved quality of housing, which should reduce overall energy consumption over its lifespan.
Another benefit of MMC is the construction of high-quality homes at a faster pace, which is desperately needed in Ireland. MMC is estimated to reduce construction time up to 8 weeks. Since components can be produced in a factory, the only thing occurring on the construction site is the installation of panels, walls or structures. This reduces onsite construction times and prevents additional risks of onsite delays, which is beneficial considering the unpredictable weather Ireland receives. With the components being built in factories, there can be standards introduced to improve quality control. This is compared to on-site construction and the increased amount of variables involved when building.
In other countries like Sweden and Japan (see appendix 1), higher quality is seen as one of the major benefits of MMC adoption. Sweden has the highest amount of MMC usage, at 45%. This is due to the environment in Sweden and the abundance of timber. Since there is severe weather in Sweden, with long winters and high amounts of rainfall, there is little time to construct housing efficiently on site. Combined with the fact that 70% of Swedens land is covered in forests, and MMC is a big incentive in Sweden. The Swedish government has also been encouraging MMC to reduce the environmental impact of the construction sector. Japan’s usage is at 15%, but their population is significantly higher than Swedens. Japan has shorter life expectancies on housing units at 26 years, and Japanese households like to build their own houses. This makes MMC an incentive as the housing can be customised to the individual household and have fast delivery, with some companies offering a full redevelopment of a property in 50 days. When looking at Sweden and Japan the commonalities of MMC is the speed of delivery and the high quality of housing produced. These 2 benefits are also highlighted in the current Irish housing plan, signifying the government's interest in MMC and the benefits it can provide.
However, there are barriers to MMC that have been discussed. In 2024, TASC published a report in collaboration with CIOB (The Chartered Institute of Building) on Modern Methods of Construction: barriers and benefits for Irish housing. The aim of this report was to understand barriers to the construction supply chain in implementing further use of MMC. One issue that arose was the costs for the contractor. While the benefits of fast delivery and sustainability are clear, the lack of a market keeps costs high. Manufacturers have difficulties with the compliance costs of MMC. Many of the products are untested since it’s a new market, and there are higher costs with re-testing products compared to tried and tested traditional construction. Another issue is around the building of social housing. The issue relating to MMC is that Local Authorities use different styles when contracting social housing units and have the power to deviate from national guidelines. Local authorities want to use MMC to speed up delivery, but targets for MMC social housing units aren’t high enough to see economies of scale.
The current housing strategy details some policy changes that address concerns identified by the TASC report. The strategy outlines how the government hopes to provide support to reduce the time span for MMC to comply. Another target is to have 25% of social and affordable housing constructed using MMC. As part of the strategy, the government has provided funding for MMC projects on 36 sites, which will deliver around 1500 social housing units across 13 Local Authorities by 2027. This 25% target benefits the compliance and economies of scale, as with state backing, businesses will be encouraged to invest in MMC in order to build the housing units.
MMC seems promising. It has grown in significance over the past 10 years, with new innovations and more research and funding being put into it. It will be interesting to follow the data the Department of Housing is collecting to see how MMC evolves over the next few years. MMC has benefits for the environment and provides high-quality homes at a faster rate. An indicator of the success of MMC will be whether it assists the government in reaching its target of 300,000 homes by 2030.
Nathan Hart
My name is Nathan Hart. I am a master's student in UCD studying Public Policy. My interests include housing, infrastructure and climate policy
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