More Timber in Construction: Unanswered Questions and Future Challenges

Can Australian plantation forest carbon offset methods increase carbon storage and timber supply? A case study from the Green Triangle plantation forestry region in Australia

The plantation forestry estate in Australia has been in decline for a decade or more. Previous studies attribute observed investment inertia to factors including the long-term nature of forestry investments, high up front establishment cost and more recently water resource constraints. The introduction of plantation forestry methods as part of the Australian Carbon Credit Unit Scheme in 2017 has generated renewed interest in plantation forestry as a carbon abatement option. To assess this opportunity, we performed high spatial resolution bioeconomic modelling of southeastern Australia's Green Triangle forestry region to understand the joint influence of site productivity, species selection and spatially variable costs including agricultural land prices and transport distances on land use change and additional future timber flows. We found that additional plantations may be economically viable at a carbon price of AU$39/t CO2e. New softwood (P. radiata) plantations provide the lowest cost option across the region when compared to hardwood (E. globulus). However, at carbon prices below AU$50/t CO2e comparatively little technically feasible abatement is possible for both plantation species with only 632,000 t CO2e from hardwood and 12.9 Mt CO2e, from softwood under economically optimised conditions which equates to 0.13 and 2.5 percent of Australia's 2023 emissions respectively. We found however that this may translate to significant additional timber flows for the region's processing industry even at lower carbon prices. We estimated an additional 62,600 green metric tonnes of hardwood (1 percent of annual Australian plantation hardwood harvest) and 6.6 million m3 of cumulative softwood (44 percent supply of annual Australian plantation softwood harvest) over a 50-year period at AU$40/t CO2e. However, the results were found to be sensitive to discount rate assumptions. The discussion focuses on the economic and policy factors that may enable/limit the use of carbon markets to expand the Australian plantation forestry estate.

Carbon footprint of low-energy buildings in the United Kingdom: Effects of mitigating technological pathways and decarbonization strategies

There is a limited comprehensive analysis of the effectiveness of adopted carbon mitigation strategies for buildings over their life cycle, that are concerned with temporal perspectives of emissions. Accordingly, this paper explores a life cycle assessment (LCA) to address the concerns regarding mitigating the carbon footprint of a UK timber-frame low-energy dwelling. In particular, it aims to investigate the potential greenhouse gas (GHG) emission reduction in terms of three different heating and ventilation options, and to analyze the influence of decarbonization of electricity production as well as the technological progress of the waste treatment of timber on the building's environmental performance. Thus, the whole life‑carbon of the building case studies was evaluated for a total of eight investigated prospective scenarios, and they were compared to the LCA results of the baseline scenario, where the existing technology and context remained constant over time. Results show that using a compact heat pump would lead to a significant whole life-cycle emission reduction of the dwelling, by 19 %; while GHG emission savings can be reinforced if the assessed systems are employed simultaneously with grid decarbonization, exhibiting a 25 %-60 % reduction compared to the baseline scenario. Moreover, technological changes in the waste treatments of timber products could substantially reduce the buildings' embodied emissions, representing 3 %-23 %. From these emission-saving measures, the contribution of material efficiency strategies to achieve more embodied carbon savings should be highlighted in future construction practices.

An Experimental Investigation of Hardwoods Harvested in Croatian Forests for the Production of Glued Laminated Timber

The aim of this study was to assess the potential of hardwoods harvested in Croatian forests for the production of glued laminated timber (glulam), mainly of those species for which there is no published performance assessment. Nine sets of glulam beams were produced: three sets using lamellas from European hornbeam, three sets from Turkey oak, and three sets from maple. Each set was characterized by a different hardwood species and surface preparation method. The surface preparation methods included planing, planing followed by sanding with fine grit, and planing followed by sanding with coarse grit. The experimental investigations included shear tests of the glue lines in dry conditions and bending tests of the glulam beams. The shear tests showed satisfactory performance of the glue lines for the Turkey oak and European hornbeam, but not for the maple. The results of the bending tests showed superior bending strength of the European hornbeam compared to the Turkey oak and maple. Planing followed by rough sanding of the lamellas was shown to have a significant influence on the bending strength and stiffness of the glulam from Turkey oak.

Climate Adaptation and Indoor Comfort Improvement Strategies for Buildings in High-Cold Regions: Empirical Study from Ganzi Region, China

The improvement of building and living conditions in high-cold areas has always been an issue worthy of attention, but there is currently no research using field survey data for evaluation. The Ganzi region, based in the western plateau of China, is a typical example for such a study. Restricted by factors such as natural conditions and economic level, the winter indoor thermal environment of western plateau houses is generally poor. Taking the new residential houses in the Ganzi region as a case study, the authors of this paper conducted field research and analyses. First, the authors analyzed the construction technology and functional layout of the building through thermal environment testing and investigation; second, the authors analyzed the user’s activity path according to the production and lifestyle; thirdly, the authors comprehensively evaluated the indoor thermal comfort through questionnaires and a predicated mean vote (PMV)-predicted percentage dissatisfied (PPD) evaluation model. The research results showed that: (1) the construction technology, functional layout, and temperature distribution of the new residential building were consistent with the user’s activity path, which could effectively improve thermal insulation ability and thermal comfort; (2) compared to the developed eastern regions, the users in the building showed a stronger tolerance and wider acceptable temperature range in the extreme climate environment; and (3) under certain cooperative work conditions, an indoor temperature of 10–14 °C could meet basic thermal environment requirements and thus lower the limits of the standards. The author’s method was proven to be more resilient than current standards in dealing with climate change. Therefore, this research can provide a practical reference for the improvement of peoples’ living conditions and sustainable development in cold regions and other harsh areas.

Mind the Gap: A Policy Gap Analysis of Programmes Promoting Timber Construction in Nordic Countries

The construction sector is one of the main contributors to greenhouse gas emissions and consumers of energy, making it one of the most relevant sectors when planning reduction strategies and policies. The use of timber in the built environment has been identified as a key strategy to reduce the carbon footprint of the construction sector. In this paper, we use the concept of policy gap analysis to identified underlying challenges in the implementation of timber construction on three Nordic countries, Finland, Norway, and Sweden. We carried out a series of semi-structured interviews with experts from the countries of study. The interviews came from industry, government, and construction companies. The use of the gap analysis approach was useful not only to identify areas that are being targeted but also those areas that were not covered by any programme at the time of study. The results showed that the studied programmes have a large level of coverage and congruence with the identified challenges. Moreover, they also showed that challenges related to fire safety regulations and insurance policies for timber buildings still need to be addressed, whereas the challenges of high price variability and lack of promotion are being addressed by multiple programmes. With this work, we have seen how timber construction is gaining momentum and how the challenges have been addressed systematically.

Coherent Investigation on a Smart Kinetic Wooden Façade Based on Material Passport Concepts and Environmental Profile Inquiry

Wood is one of the most fully renewable building materials, so wood instead of non-renewable materials produced from organic energy sources significantly reduces the environmental impact. Construction products can be replenished at the end of their working life and their elements and components deconstructed in a closed-loop manner to act as a material for potential construction. Materials passports (MPs) are instruments for incorporating circular economy principles (CEP) into structures. Material passports (MPs) consider all the building’s life cycle (BLC) steps to ensure that it can be reused and transformed several times. The number of reuse times and the operating life of the commodity greatly influence the environmental effects incorporated. For a new generation of buildings, the developing of an elegant kinetic wooden façade has become a necessity. It represents a multidisciplinary region with different climatic, fiscal, constructional materials, equipment, and programs, and ecology-influencing design processes and decisions. Based on an overview of the material’s environmental profile (MEP) and material passport (MP) definition in the design phase, this article attempts to establish and formulate an analytical analysis of the wood selection process used to produce a kinetic façade. The paper will analyze the importance of environmentally sustainable construction and a harmonious architectural environment to reduce harmful human intervention on the environment. It will examine the use of wooden panels on buildings’ façades as one solution to building impact on the environment. It will show the features of the formation of the wooden exterior of the building. It will also examine modern architecture that enters into a dialogue with the environment, giving unique flexibility to adapt a building. The study finds that new buildings can be easily created today. The concept of building materials passport and the environmental selection of the kinetic wooden façade can be incorporated into the building design process. This will improve the economic and environmental impact of the building on human life.