With the worldwide construction sector being responsible for one-third of carbon dioxide emissions, as well as forty percent of the world’s energy use and waste production, a shift to sustainable and renewable construction techniques is crucial. Engineered timber, champion of sustainable construction materials, has evolved to a stage that enables the construction of not only family housing but also taller buildings commonly built from concrete or steel.

In the scope of the European Green Deal and the new emission targets set by the European Commission (55 percent reduction by 2030 and carbon neutrality by 2050), it is imperative that the building sector changes dramatically. Increased use of timber in construction forms a cornerstone of that transition. To achieve a sufficient share of timber buildings, it is necessary to use timber not only for family houses but also for taller multistorey buildings that make up a major part of the global construction sector. Timber building design codes are still in development, and a substantial part of building design legislation is subject to national regulation that is uncorrelated to timber building demands. Therefore, there is a great need for pan-national design guidelines, founded on holistic assessment of timber buildings, that provide integrated design principles. Documents available today give only partial information and do not consider the number of possible issues and design collisions originating from different building design fields.

COST Action HELEN – “Holistic design of taller timber buildings” is working on tackling the challenges related to the design of taller buildings made from timber. It is a project funded by the COST (European Cooperation in Science and Technology Association, which is working towards optimized holistic approaches to improve the performance of taller timber buildings and to widen their competitiveness and use across the EU and the rest of the world. COST is a funding organisation for research and innovation networks. COST Actions help connect research initiatives across Europe and beyond and enable researchers and innovators to grow their ideas in any science and technology field by sharing them with their peers. COST Actions are bottom-up networks with a duration of four years that boost research, innovation and careers.

COST Action HELEN has over 300 participants in 46 countries around the world, of which 34 are COST member countries. The project will last 4 years, beginning in October 2021 and ending in October 2025. The grant holder and administrator of the project is the InnoRenew CoE from Izola, Slovenia.

The main objective of this COST Action is to address taller multi-storey timber buildings from a collaborative and interdisciplinary perspective, considering static, dynamic, fire, acoustic, human health and other aspects in parallel and not in isolation. The second objective is to change the paradigm of building construction research, shifting R&D from isolated topics to an integrated interdisciplinary approach, which is critically necessary to safely design and build, as well as correctly maintain and recycle taller timber buildings.

COST Action HELEN is organized into 4 interdisciplinary working groups to achieve our goals in the field of multi-storey timber building design. The Action is a unique opportunity that brings together all engineering and non-engineering fields to assess these buildings from an interdisciplinary perspective and address topics such as robustness, adaptability, repairability, and reusability of taller timber buildings.

This COST Action goes beyond the design codes which for the most part only focus on individual design fields or specifics. It brings together a spectrum of engineering fields that are involved in a building’s design, along with the architects and builders. The Action also strives to bring investors, municipalities, and policymakers on board.

Through an interdisciplinary debate, the potential issues multistorey buildings may face can be identified more quickly, easily, and more importantly before they occur in practice. The practice has already come a long way, however with the European as well as global efforts to increase timber construction, we will be running into new challenges – this Action strives to be one step ahead of these challenges.

COST Action HELEN produced a state-of-the-art report to assess the current state of things and identify challenges in midrise timber buildings. This four-part report, nearly 400 pages long, gives an overview of a wide range of topics that contemporary multistorey timber buildings face (or will face soon). The first part deals with design for robustness, adaptability, disassembly, reuse, and repairability; the second part with deformations and vibrations; the third part with accidental loads; and the fourth with sustainability and durability. Download the report.

This state-of-the-art forms a base for further discussions within the interdisciplinary group in COST Action HELEN. Data will be further supported by future activities, including interdisciplinary interactive surveys, workshops and training schools, and short-term scientific missions that are planned in the upcoming years.

COST Action HELEN will change the paradigm of building construction research, shifting R&D from isolated topics to an integrated interdisciplinary approach, which is critically necessary to safely design and build as well as correctly maintain and recycle taller timber buildings. Namely, designing taller buildings made from timber is much more demanding than their concrete and steel counterparts.

It is therefore crucial to address taller multi-storey timber buildings from a collaborative and interdisciplinary perspective, considering static, dynamic, fire, acoustic, human health and other aspects in parallel and not in isolation. Only through interdisciplinary analysis and interaction can a set of holistic design guidelines be developed that will enable safe construction of taller timber buildings, as well as respect human well-being demands.

The next step is to identify the interactions that are missing. Soon we will be releasing a survey to identify these design “collision areas”. It will be open to anyone who wants to contribute! Watch our website and social media for the survey.

Each year COST Action HELEN provides opportunities for Action participants to network and work towards our goals. Events include Meetings, Training Schools, Short-Term Scientific Missions (STSM) and Conference grants.

In June 2024, COST Action HELEN held a Training School – Sustainability of Taller Timber Buildings in Zagreb, Croatia. 8 Trainers educated 24 Trainees about the Sustainability of Taller Timber Buildings and provided the opportunity to learn more about timber building durability, environmental key performance indicators, and the evaluation and validation of timber data. Additionally met fellow researchers from other European universities for networking.

In May 2024, the 4th Working Group Meeting & MC Meeting was held in Hasselt, Belgium. 105 participants from at least 26 countries met in person and online to work towards the goals of the Action.

When the Action finishes, it will be providing the timber construction industry, building investors and users with guidelines that will enable safer, more robust, and more comfortable multistorey timber buildings with optimal raw material use.

COST Action HELEN has many opportunities for collaboration, including joining the Action; attending events like Meetings and Training Schools; participating in a Short-term Scientific Missions (host or researcher); applying for a Conference grant; downloading resources on the website; and following the Action on LinkedIn.

Author: Amy Simmons