To date, in the literature, there has been no study on the comparison of hybrid (timber and concrete) buildings with counterparts made of timber and concrete as the most common construction materials, in terms of the life cycle assessment (LCA) and the carbon footprint. This paper examines the environmental impacts of a five-story hybrid apartment building compared to timber and reinforced concrete counterparts in whole-building life-cycle assessment using the software tool, One Click LCA, for the estimation of environmental impacts from building materials of assemblies, construction, and building end-of-life treatment of 50 years in Finland. Following EN 15978, stages of product and construction (A1–A5), use (B1–B6), end-of-life (C1–C4), and beyond the building life cycle (D) were assessed. The main findings highlighted are as following: (1) for A1–A3, the timber apartment had the smallest carbon footprint (28% less than the hybrid apartment); (2) in A4, the timber apartment had a much smaller carbon footprint (55% less than the hybrid apartment), and the hybrid apartment had a smaller carbon footprint (19%) than the concrete apartment; (3) for B1–B5, the carbon footprint of the timber apartment was larger (>20%); (4) in C1–C4, the carbon footprint of the concrete apartment had the lowest emissions (35,061 kg CO₂-e), and the timber apartment had the highest (44,627 kg CO₂-e), but in D, timber became the most advantageous material; (5) the share of life-cycle emissions from building services was very significant. Considering the environmental performance of hybrid construction as well as its other advantages over timber, wood-based hybrid solutions can lead to more rational use of wood, encouraging the development of more efficient buildings. In the long run, this will result in a higher proportion of wood in buildings, which will be beneficial for living conditions, the environment, and the society in general.

Purpose: This study examined data from 13 international tall residential timber building case studies to increase our understanding of the emerging global trends.Design/methodology/approach: Data were collected through literature surveys and case studies to examine the architectural, structural and constructional points of view to contribute to knowledge about the increasing high-rise timber constructions globally.Findings: The main findings of this study indicated that: (1) central cores were the most preferred type 10 of core arrangements; (2) frequent use of prismatic forms with rectilinear plans and regular extrusions were identified; (3) the floor-to-floor heights range between 2.81 and 3.30 m with an average of 3 m; (4) the dominance of massive timber use over hybrid construction was observed; (5) the most used structural system was the shear wall system; (6) generally, fire resistance in primary and secondary structural elements exceeded the minimum values specified in the building codes; (7) the reference sound insulation values used for airborne and impact sounds had an average of 50 and 56 dB, respectively.Originality/value: There is no study in the literature that comprehensively examines the main architectural and structural design considerations of contemporary tall residential timber buildings.

As a result of increasing urbanization, the need for sustainable housing, e.g., tall (over eight-story) timber apartments, is increasing in Finland. Leveraging the experience of key Finnish professionals plays a significant role in the transition and expansion of sustainable timber housing as an essential part of the forest-based bioeconomy. This interview-based study will serve to fill a gap by examining the views of key professionals with experience in tall timber residential construction, using Finland as a case study. The 21 interviews primarily highlighted that: (1) the construction cost was the most important parameter affecting the architectural and structural design; (2) the most critical consideration influencing the overall design was reported to be the structural system selection and structural design, followed by city planning and client control; (3) key professionals assessed the building’s form and the main dimensions of the building’s mass as the most significant parameters affected by timber construction; (4) the main structural considerations that needed to be developed for tall timber housing were the bracing solutions and fittings, the structures of the intermediate floors, and load-bearing vertical/partition structures; (5) construction preconceptions, the lack of cost-competitiveness, and the lack of construction expertise/actors were considered to be major obstacles; (6) the most important parameters for the future of tall timber apartment buildings were reported to be education, timber construction marketing and public awareness, land delivery conditions, the unification of public administration, and financial support; (7) tall timber building design was reported to be a complex subject that requires close collaboration, especially between the architect, the structural designer and the wood supplier. This paper will help us to understand the boundary conditions affecting the design, the development needs in solutions, the importance of design parameters, the design parameters affected by timber construction, and the prospects, measures and obstacles to tall timber apartments from the perspectives of key Finnish professionals, thereby aiding the sound planning and development of tall timber housing projects.

This paper examined wood preservation practices and outlook considering climate change from the perspective of Finnish experts through interviews. Key findings highlighted that: (1) pressure impregnated wood will continually evolve and secure its market, and it seems worthy of developing modified wood products, especially with the increasing attention to recyclability and lifecycle concepts; (2) demand for highly processed surface treatment products is high; (3) opportunities for more sustainable and environmentally friendly wood preservation methods, and thus production volume will increase in the future; (4) increasing mold problems in Finland due to climate change make surface treatment more important than ever; (5) demands for fire protection treatments are increasing, but fire testing fees and processes have slowed product development; (6) although the possibility of the spread of termites triggered by global warming to Finland seems to be a future scenario, this issue needs to be considered in products exported to hot countries; and (7) preservatives have become more critical to protect untreated wood from the adverse effects of climate change. It is believed that this study will help accelerate the transition of innovative and environmentally friendly wood treatments on the Finnish market, thereby promoting the use of wood in the building construction industry.

Purpose: The paper aims to understand Finnish architects' attitudes towards the use of timber as a structural material in multi-storey (over two--storeys high) residential construction.Design/methodology/approach: The study was conducted through a literature survey mainly including international peer-reviewed journals and similar research projects. Furthermore, the literature survey informed the generation of the web-based survey questionnaire design to gather information on architects' perceptions, attitudes and interest in the use of wood in multi-storey (over two-storeys high) residential buildings.Findings: The paper's findings are as follows: (1) respondents perceived the most important advantages of wood as a lightweight, local and ecological material; (2) wood construction (compared to concrete) included perceived concerns about it being more costly and needing more complex engineering and (3) respondents had a favourable overall attitude towards the use of wood particularly in low-rise residential construction, whilst their perception of tall housing, including timber ones, was mostly negative.Originality/value: No studies have evaluated the use of wood in tall residential buildings and architects' perceptions in Finland.

Due to increasing urbanization, the need for sustainable housing, e.g., sustainable timber housing, is increasing in Finland, as in other countries. Understanding residents’ perceptions plays a critical role in the transition to sustainable housing as an important part of the forest-based bioeconomy. This study examined the change over time in Finnish residents’ attitudes towards multi-story timber apartment buildings. To do this, findings from surveys among residents in 1998–1999 and 2017 were compared with each other. Results mainly highlighted that: (1) residents’ attitudes towards timber apartment buildings remained positive over time; (2) participants of both surveys were satisfied with functionality of the apartment unit, immediate surroundings of the building, and number of furnishings and appliances; (3) positive perception regarding sound insulation, indoor climate, and coziness did not change over time; (4) dominant preferences to move to detached and one-or-two story terraced houses gradually gave way to two-story housing and apartment buildings; (5) demand for more timber inside the building and more timber apartments continued over time; and (6) while fire and environmental properties were evaluated positively, impact sound insulation was still seen as a problem. These findings will assist in understanding contemporary housing needs and provide a direction to relevant stakeholders for Finnish housing development.