The growing climate crisis and the challenging housing market are some of the most pressing challenges society faces today. Efforts have been, and are being, made across various industries to address these issues, including in the construction industry.

Contrary to the belief of some, the construction industry can offer both a sustainably focused and cost-effective means of helping to address these issues, through the use of mass timber. In this article, both the benefits and risks associated with this material are analysed.

Mass timber is a wood product, created when thick layers of wood are laid across one another and compressed to form durable, structural panels that can be used in the construction of homes and buildings as a base material.

There is evidence of an increased use of mass timber in the construction industries in several jurisdictions and we expect to see a continued uptake in Ireland. The Timber in Construction Steering Group was recently established in Ireland. This consists of representatives from industry bodies and governmental departments and has as its goal “to increase the use of timber in construction whilst ensuring the highest degree of building safety and property protection; to examine regulatory and standardisation challenges; and to maximise the use of home-grown timber in construction.”

In light of the growing momentum to incorporate timber into construction projects, there are a number of benefits and risks, of which all parties in the industry (developers, contractors, funders and insurers alike) should be aware before delivering a project which utilises mass timber as a base material.

Benefits

First, timber, when utilised as a raw material in building, has a far less adverse impact on the environment than the traditional building materials typically used. The importance of prioritising a renewable and sustainable raw material in construction projects is heightened in light of the Government’s commitment to reduce greenhouse gas emissions by 51% in 2030, with net-zero emissions to be achieved by 2050. Indeed, the Recast Energy Performance of Buildings Directive will mandate a new standard of zero-emissions for all new builds by 2030. Mass timber will certainly provide a pathway to assist Ireland in meeting these EU requirements.

Secondly, the process for manufacturing mass timber is typically undertaken off-site, with the finished product delivered to the site ready for immediate incorporation into the construction project. Off-site production facilitates cost savings for developers, by removing the time spent on assembling raw materials on-site, reducing the number of workers required and ultimately lowering fees under construction contracts. This of course also carries with it a reduced carbon impact for the project overall. The efficiency and sustainability of mass timber may also be a welcome development for the delivery of public housing and other publicly owned buildings, given the backdrop of high demands to construct more residential and commercial buildings in already densely populated cities throughout the country.

Risks

Mass timber is certainly not without its risks, but once effectively managed by all parties, these risks should not prove insurmountable to its increased uptake in projects.

It will come as no surprise to anyone that timber is a far more flammable substance than traditional building materials. The risks surrounding the fire resistance levels and general durability of mass timber, when exposed to weather conditions, will need to be properly accounted for and allocated between developers and contractors when entering construction contracts. Professional indemnity insurance premia may rise considerably beyond the market standard for parties such as contractors, fire safety consultants and other professionals who are required to provide a collateral warranty or certificate of compliance during or at the end of a construction project. Insurers may have understandable concerns about insuring projects involving such a combustible material.

However, when mass timber is treated sufficiently during manufacturing and maintained on an ongoing basis post-construction, it is possible to increase its fire resistance, as well as longevity, to a level with which all parties could get comfortable.

A further risk associated with mass timber stems from the nature of its off-site manufacturing. When choosing mass timber as a base material, a developer will need to engage a supplier/contractor who will be responsible for assembling the material off-site. This supplier/contractor may also be responsible for sourcing this material and carrying out further services such as treating the timber, or ensuring that it has been treated, with fire-resistant properties. It is expected that fees will be required up-front to fund these services, which leaves the employing party exposed to the risk of non-delivery should the supplier/contractor become insolvent prior to delivery. This risk of course arises with off-site manufacturing generally and can be managed through appropriate mechanisms such as vesting certificates and/or bonds.

Takeaways

It appears that the main risks associated with the use of mass timber stem from a lack of awareness in the construction industry of its potential and a lack of understanding of how to best navigate and mitigate its hazards. This is of course to be expected given its limited use in projects at this stage. Although the NSAI has provided national standards for the manufacturing of timber frames in Ireland and the guidance documents, supplementary to the Irish Building Regulations, reference a number of Irish and European standards on timber, there remains a lack of detailed guidance on constructing with this material. For example, a fire-resistant certified testing standard for mass timber products, as well as further technical instruction for timber buildings, would be welcomed by all parties involved in construction. These advances might assist the industry in getting comfortable with using mass timber, as well as pave the way for a review of the current regulatory framework which prohibits the construction of timber buildings above three storeys.

With governments across the UK, Europe, the US and Canada all regulating for the increased use of mass timber in construction and our own public bodies setting new targets for the material (in particular, Coillte aims to increase the amount of timber homes across the country “from 20% to 80% by 2050”), there is evidence of a consensus on a global level that the use of timber is a very attractive option in combatting high construction demands while minimising environmental impacts.

Whether long-term benefits outweigh risks will become clearer with further research and direction on the parameters of the use of mass timber. The real test will be in whether we see an uptick in the levels of manufacture and deployment of mass timber alongside the more traditional materials prevalent in the industry.

The author would like to acknowledge Sorcha Ryder’s contribution to this article.

Author: Shane O’Neill, Partner www.arthurcox.com

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