Background: Pathway towards greener timber construction
Today, the broad policy frameworks at EU and national levels are all aligned towards the implementation of the Green Transition, which requires a profound transformation of the economy, industry, society, and social behaviours. In this context, timber as a construction material has gained considerable attention in recent years, not only as an efficient way towards achieving carbon neutrality in the construction sector, but also for its potential in generating significant economic opportunities.
Timber construction systems in Nordic and Baltic countries are highly advanced despite many continuing to associate wooden buildings with being old-fashioned, low-tech, small-scale, or less durable. The industry is proving these misgivings wrong. Modern timber buildings can meet the highest standards of quality, and design and can be built of nearly any dimension.
Modern timber construction systems use either elements and modules (volumes), and/or engineered wood products (Mass Timber) which are prefabricated offsite. Modules are LEGO-like building blocks in human scale that can come out from the factory with all electrical installations, heating, plumbing, and air-conditioning systems (Picture 1). Mass timber are structural materials made by gluing wood, veneers, panels, strands, or fibres together to build the frame of buildings and even bridges (Picture 2). The key advantages of these systems, aside from replacing concrete and steel, is that they can be used to build in height (multi-storey buildings) and can be highly industrialised (up to 95% completion offsite) to scale-up production cutting costs and energy, and replacing the slow and cumbersome process of building onsite. 
Despite the clear opportunities, greening the construction sector by increasing the adoption of timber building systems, will not be achieved via technological innovation alone. Innovation and industrialisation of modern timber construction systems has been a gradual process that has taken over a century.
Changes to legislation introduced from the 1990’s and onwards in different countries, have opened the door for multi-storey buildings made of timber. This is a game-changer for the industry. Yet, the increase in market share has been much slower than expected.
Sweden took the lead by removing all bans on multi-story building in 1995 and formulated a national strategy that came into effect in 2005 to support timber construction. Substantial efforts were mobilised to aid innovation and industrialisation, generate knowledge, skills, and experience. Yet, creating market conditions also required great efforts from policy, industry, research, and ‘place leaders’ (irrespective of their formal position). The unchallenged hegemony of well-established systems consolidated over time a strong network of actors along supply-chains that reinforce the status quo. In addition, planning systems, finance and business models, insurance conditions, among other nodes in the system, are specifically tied to the establishment, challenging the emergence of alternative systems.
After decades of hard work, timber construction has made its way into the market in Nordic and Baltic countries (beyond an already established market for single-family homes), initially with pilot projects and often iconic buildings aimed at shaking up societal perceptions, such as Sara Cultural Centre in Skellefteå, Sweden (Picture 3) or the Pelgulinna Highschool in Tallinn, Estonia (Picture 4). But in several countries, timber buildings have now created a market niche within the ‘regular’ market of multi-story buildings. Timber buildings in Sweden have reached a 20% share, in the apartment building market, which provides a sufficient foundation for reassuring investors and regulators of the technical and financial viability of this emerging industry. 