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Entry

Wooden Additional Floor in Finland

by
Anu Soikkeli
1,
Hüseyin Emre Ilgın
2,* and
Markku Karjalainen
2
1
School of Architecture, University of Oulu, FI-90014 Oulu, Finland
2
School of Architecture, Faculty of Built Environment, Tampere University, P.O. Box 600, FI-33014 Tampere, Finland
*
Author to whom correspondence should be addressed.
Encyclopedia 2022, 2(1), 578-592; https://0-doi-org.brum.beds.ac.uk/10.3390/encyclopedia2010038
Submission received: 3 February 2022 / Revised: 25 February 2022 / Accepted: 3 March 2022 / Published: 7 March 2022
(This article belongs to the Collection Encyclopedia of ZEMCH Research and Development)
Browse Figures
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Definition

:
One of the most effective ways to cover real estate development and renovation processes by improving functionality and energy efficiency is wooden additional floor construction. This entry maps out, organizes, and collates scattered information on the current state of the art and the benefits of this practice including its different stages, focusing on the case of Finland. The entry presents this topic in an accessible and understandable discourse for non-technical readers. By highlighting the benefits and opportunities of this sustainable application, the entry will contribute to increasing the awareness of wooden additional floor construction, which has many advantages, and therefore to gain more widespread use in Finland and other countries.

1. Introduction

Among the targets of the European Union’s 2050 Energy Roadmap are the decarbonization of increasing energy resources, making more use of renewable energy, and improving energy efficiency [1,2]. In line with these sustainable goals, Finnish building regulations were revised and developed, allowing new construction methods to be more energy-efficient [3,4,5]. Most of Finland’s building stock consists of buildings that were erected before the 1990s, have very low energy efficiency, and are mostly in the renovation era [6,7]. More than 30% of residences, which constitutes a substantial part of the building inventory in Finland, are apartment buildings constructed in the Finnish suburbs in the 1960s and 1970s and need refurbishment [8,9,10].
The thermal insulation of these Finnish suburban apartments was poor, and at that time, no regulations or targets were set for this in Finland, and as a result, these buildings needed a serious energy upgrade [11]. Energy upgrade strategies, especially for the old housing inventory, should be adopted as an important approach to increase energy efficiency because, with the erection of new buildings, the rate of renewal of the building stock has not even reached two percent per year [12]. Overall, besides the lack of equipment and poor technical conditions, among the most important problems of Finnish suburban apartments is poor energy efficiency [13,14].
As in many other countries, it takes a lot of investment and government subsidies to renovate a building by increasing its energy efficiency in Finland [15,16,17,18]. Additionally, it is difficult to find a contractor who can undertake or is willing to undertake suburban apartment renovations, and it is often necessary to seek and hire more than one contractor for a project in Finland [19]. Real estate and housing companies play a key role in renovating old apartments in Finland [20]. There are more than 60,000 flats where almost half of Finland’s population resides [6]. Real estate and housing companies that require financing instruments to refurbish and improve their properties often play an important role in the maintenance and modernization of apartments [21]. In addition, renovation projects involve excessive work and strong coordination of residents as well as building managers and housing companies [22]. In practice, building renovations are a slow, expensive, dirty, and destructive process [23]. This is mainly because refurbishment projects in Finland often use operational models created for new construction [24].
It is worth mentioning here a local Finnish challenge stems from the ownership of buildings [25]. Single people have their flats and a piece of land below. They co-manage housing companies that must make a joint decision to fund their new investments, where redevelopments are often financed by a bank loan. This amount is then directly attributed to the occupant’s share of the total renovation costs. Parking space is another challenging issue if parking lots need to be constructed to replace old parking lots and offer additional parking spaces.
In Finland, one of the most effective ways to cover real estate development and renovation processes by improving functionality and energy efficiency is the construction of an additional floor [24] (Figure 1). When the building height and the number of building stories increase or the roof form changes, the terms additional floor, roof, or elevation construction are used [26]. Furthermore, additional floor construction provides numerous opportunities and benefits such as increased owner income, short-term income to housing companies by selling the building rights or areas of additional floors, as well as a relatively lower carbon footprint, increased gross floor area, and improved building appearance [26,27,28] (see Section 3).
Important issues requiring special attention in additional floor projects in the Finnish context are as follows [29]: (i) Economic feasibility: This consideration, which has become more important with the sale of building rights to the outside party that built the additional floor, poses a significant problem if the commercial return of the additional floors is not properly estimated, which means the targeted profit for the project will not be achieved; (ii) change in the city plan or deviation from the city plan: This issue, which directly affects the right to build on the land, also has an impact on the amount of property tax; (iii) finding a suitable contractor: As the cost of maintaining the property increases over time, it is very important to find a contractor who will build the additional floors as soon as possible; (iv) obtaining expert opinion: The presence of an expert is especially important for identifying and then minimizing risks. In some municipalities in Finland, the procedure for making changes to the city plan is suspended unless the relevant expert is included in the project.
The intensification of Finnish urban environments is an adopted Eurocentric goal in tackling climate change, driven by the needs of continued urbanization and the environmental impact of low-density urban structures. In this sense, European building retrofit and urban renewal applications have shown that the expansion of building volumes, such as the construction of additional floors, has significant potential [25].
Technical features (e.g., structural and architectural issues) of reinforced concrete apartment blocks built between the 1960s and 1980s in Finland generally allow the construction of additional floors, often designed as lightweight structures [29]. They are suitable for these implementations with both their structural capacity and flat roof. The current Finnish fire code also gives the green light to the construction of additional floors [30]. The Finnish fire regulations make it possible to construct the top floor of a class P1 building with a timber-framed additional floor without automatic extinguishing equipment if the building has no more than seven stories. Two additional stories require a sprinkler system on the topmost old floor and additional floors (Figure 2). There are three main fire classes, P0, P1, and P2, used for apartments in Finland [30]. While the P1 fire class represents the structural frame in which non-combustible materials such as concrete are used, wooden load-bearing systems are classified in the P2 category. On the other hand, the P0 category is based on the calculation method and is used when deviating from standard table values.
Material selection is important for refurbishment in terms of sustainability. Considering sustainable construction concerns, the renovation materials must be environmentally friendly, long-lasting, renewable, reusable, and their production must require the least amount of energy and produce a minimum amount of greenhouse gas emissions [31,32,33,34]. Studies in the literature have indicated that timber has numerous benefits over traditional building materials such as brick, concrete, and steel, and with its environmentally friendly properties in particular, timber is a suitable material for renovation [35,36,37,38,39,40,41].
In this context, wooden structures are considered lower carbon structures and represent lower embodied energy consumption compared to non-wood structures [42,43,44,45,46,47]. In addition, buildings using concrete and steel structural systems embody and consume 20% and 12% more energy, respectively, compared to buildings with wooden structures, so structural material selection plays an essential role in the amount of embodied carbon [48]. Furthermore, both in production and on-site construction, concrete and steel structures utilize 50% and 7% more resources compared to wooden structures, generating 16% and 6% more solid waste, respectively [49]. Overall, the construction of wooden buildings is in line with the sustainability goals of the European Union [50], where timber as a building material is considered to lower carbon emissions in the building construction sector and is a method of transitioning to a sustainable bio-economy.
The construction phase of timber buildings can deliver considerable savings with over 50% faster assembly times compared to traditional construction materials [51]. Timber construction offers light and prefabricated alternatives with various size and thermal insulation options to respond to special demands [52,53,54]. The prefabrication process ensures that facade elements such as doors and windows are integrated into the prefabricated units (Figure 3) [55]. In addition to being used as a construction material, after completing its service life, timber can be reused as a raw material for other buildings, or it can be burned instead of fossil fuels as a last resort [56,57,58].
The attitudes of residents towards new construction methods (e.g., a wooden additional floor) have an important role in the spread of these practices [59]. Moreover, the positive attitude of residents is a critical aspect in the effective execution of extensive refurbishment [60]. In this sense, the survey by Karjalainen et al. [25] showed that participants generally assessed the construction of wooden additional floors positively and thought that it would contribute to the attractiveness of the residential area.
The combustibility of timber may limit its use as a construction material in Finland, as in many countries, due to constraints on building regulations [61,62,63]. Various studies have been carried out recently on the fire behavior of wooden buildings around the world, aiming to provide fundamental data on the safe use of wood (e.g., [64]). As a result of extensive testing, new fire design concepts and models were developed, and existing advanced knowledge in the fire design area of wooden structures together with technical precautions, especially well-equipped fire services and sprinkler systems, ensure the safe use of wood in a wide range of applications as seen in the building code relaxations introduced in recent years [65]. In this sense, fire safety engineering and performance-based design offer benefits and challenges for the use of timber in buildings, where the performance-based approach is primarily based on the use of fire engineering principles, calculations, and modeling instruments (e.g., structural models, thermal models) to meet building regulations, considering fire modeling, full-scale structural fire experiments, and experience from fire accidents in timber structures [66,67,68,69]. Additionally, the following considerations stand out in terms of the implementation of fire safety design in wooden structures [70,71,72,73]: Manual firefighting, sprinklers, encapsulation, fire retardants, fire performance and fall-off times of protective systems, the fire performance of connections between structural timber elements, details to prevent the internal spread of fire, external fire spread in the same building, and quality assurance. Furthermore, timber and steel structures have some similarities and differences in terms of fire safety measures [65,74]. Some fire regulations, such as those in Canada, encourage full encapsulation of timber frames to ensure equivalent fire safety to the non-combustible steel frame structure. In terms of performance-based design, performance-based formulations of requirements for timber structures can be considered to provide a fire-safety equivalent to regulatory steel structures. Regarding structural modeling, wooden structures are usually easier to model than steel structures because the wood has poor thermal conductivity and does not undergo considerable thermal expansion. In the manual fire extinguishing strategy, the fire risk will be greatly reduced if immediate action is taken to contain the fire, and this reduction in fire load is adjusted for steel frames. This method is also permissible for timber structures. Moreover, in terms of external fire spread in the same building, timber facades can also be used as fire-resistant facade cladding in steel structures.
Issues with wooden structures, especially sound insulation and moisture, require special insulation and protection techniques. To obtain good air-borne sound insulation, the partitioning wall and intermediate floor structures should be built in layers and the layers should be separated from each other so that the sound does not pass through the structure [75,76]. On the other hand, humidity issues lead to both reduced durability and mold growth, which can affect indoor air quality and have adverse health consequences [77]. The best strategy for providing a moisture-resistant structure is to ensure that the wood is not exposed to water or high relative humidity for extended periods. Neglecting moisture safety can mean a high risk of damage, with extensive costs and consequent time delays for research, decontamination, or material replacement [78].
Wood-based composite materials and wood frame-based hybrid structures are among the important topics in today’s wood construction literature. In general, owing to the destruction of forest resources and recently developed technologies for wood-based composite materials in particular, engineered wood products have gradually replaced traditional materials for residential construction [79]. These materials are produced from similar materials based on wood products, e.g., timber or lumber processed into boards, or wood chips [80], and the residential and commercial building construction industry is among the areas where wood-based composites are most in-demand [81,82]. On the other hand, the idea of hybrid structures that combine multiple materials, such as timber, along with steel and/or concrete, is gaining increasing acceptance in the engineering community [83]. Moreover, hybridizing timber with other structural materials is one of the most popular approaches for designing high-rise timber buildings [84,85,86,87] as in the case of Brock Commons Tallwood House (Vancouver, BC, Canada, 2017) [88].
The three critical components of timber frame construction are the floor, the roof, and the load-bearing wall, which have significant effects on occupants’ comfort. The wood floor, the most common system component, is in frequent physical contact with building inhabitants [89]. The dynamic movement of people or objects caused by defects or deficiencies in the structural performance of the floor can cause occupant discomfort. Movements, e.g., walking, running, jumping, can create structural vibrations on the wooden floor, which adversely affect the efficiency of work and quality of life [90]. However, environmental excitation and impact excitation vibration tests as well as comfort analyses of timber floors offer solutions to these undesirable situations [91]. In addition, particularly nowadays, when standard structures are supported by contemporary technologies such as wooden floors combined with underfloor heating, it is necessary to meet technical guidelines and specifications during the operation of the floor as a whole [92]. Moreover, in line with the ‘smart building’ concept, wood, namely wood flooring, is used as an ideal material to be applied in triboelectric nanogenerators for large-scale applications in smart houses [93]. This ensures that mechanical energy (for example, the movements of residents) is directly converted into useful electricity [94,95,96,97].
Although there are numerous research studies on different construction solutions with the use of engineered timber products with related technical features (e.g., [98,99,100,101,102,103,104,105,106,107,108,109]), several studies have focused on the use of wood as a building material from the viewpoint of construction professionals (e.g., [110,111,112,113,114,115,116,117,118,119]) and consumers or users (e.g., [120,121,122]). On the other hand, to date, there has been a limited number of studies on wooden additional floor applications, especially in the housing construction industry.
This entry maps out, organizes, and collates scattered information on the current state of the art, as well as benefits and challenges of wooden additional floor projects with their different stages, focusing on the case of Finland, and presents it in an accessible and understandable discourse for non-technical readers. This entry also provides a methodical literature analysis on international peer-reviewed studies and research projects. By highlighting the advantages and opportunities of these sustainable practices, the entry will contribute to an increase in the awareness of wooden additional floor construction, which has many advantages and therefore help to gain more widespread use in Finland and other countries.
In this entry, timber or wood refers to engineered timber products [123,124], e.g., cross-laminated timber ((CLT) is a wood panel product made from gluing together layers of solid-sawn lumber), laminated veneer lumber ((LVL) is produced from veneer and is designed for structural framing where high strength and rigidity are required), and glue-laminated timber (glulam) ((GL) consists of layers of dimensional lumber glued together with durable, moisture-resistant structural adhesives).
The remainder of this entry is composed as follows: First, a literature survey is provided. This was followed by a section on the benefits, challenges, and drawbacks of wooden additional floor construction. Finally, the conclusions and prospects of the research are presented.

2. Literature Survey

As mentioned above, there are a limited number of studies on wooden additional floor construction. Among them, Karjalainen et al. [29] analyzed the different stages of wooden additional floors in old apartments from the standpoint of housing and real estate firms in Finland via interviews with involved professionals. Their result indicated (a) meticulous scrutiny of commercial conditions was critical to a profitable investment; (b) a change in the city plan, finding a suitable contractor, and involving an expert were among the highlights; (c) for the feasibility phase, the importance of parking space, load-bearing capacity, and compatibility with building regulations was emphasized; (d) during the project planning phase, attention was drawn to the importance of current building regulations and building rights concerning taxes and fees; (e) during the implementation planning process, city plan changes and different tender conditions came to the fore; and (f) effective information sharing between parties was a critical parameter for the successful completion of the construction phase.
Similarly, highlights of the study by Karjalainen et al. [125] were (a) the feasibility study emphasized the property’s condition and potential targets for improvement, as well as relevant codes and regulations in force; (b) construction cost, profit, and sales of building rights were among the issues that were frequently discussed during the project planning phase; (c) building rights, changes in the city plan, and conditions of the company managing the property were reported as significant issues during the implementation planning phase, and (d) regular and frequent updating of building occupants on the progress of the construction process was the backbone of the construction phase.
On the other hand, Karjalainen et al. [26] conducted a survey and discussed the residents’ approach to wood facade renovation and additional floor construction from Finnish residents’ standpoint. Their study highlighted the following regarding additional floor construction: (a) Residents’ attitudes were mostly positive; (b) younger and more educated people approached these practices much more positively; (c) respondents generally thought that additional floor construction will increase the attractiveness of residential areas; and (d) apartment owners positively appreciated the housing association’s decision for additional floors to finance the facade refurbishment.
Soikkeli and Sorri [19], Soikkeli et al. [23], and Soikkeli [24] presented a research project (Finnish national research project, User- and Business-oriented Suburb Renovation Concept [KLIKK]) targeted to develop an industrial-scale, viable, and effective method for refurbishing and implementing additional floors to old apartment buildings. The technical solutions that form part of the concept were actively taking advantage of the opportunity offered by the new Finnish fire codes for the use of timber structures during renovations.
Cronhjort et al. [25] discussed obstacles and benefits for the utilization of wood-based approaches for infill development and building extensions in Finland by examining architecture and engineering master’s theses. Their findings highlighted (a) there was a potential for infill development in the Finnish municipalities; (b) the applicability of vertical extensions that increase the functionality and quality of life was also demonstrated; (c) the added value of using timber-based prefabricated solutions in each case was shown; and (d) environmental, financial, and social advantages of infill construction, which is one of the Finnish national targets in provincial and land use, were evident in the case studies.
In addition, there are several studies on the vertical extension of buildings conducted in other countries. Prominent among these studies, Leskovar et al. [126] aimed to verify the effect of a structural lightweight wood–glass upgrade module and building a vertical extension on the energy efficiency of the selected renovated building concerning the relationship between the volume sizes of the existing building and different types of upgrade modules in Slovenia. The results showed great potential to reduce the energy consumption of existing inefficient buildings and simultaneously addressed the problem of urban sprawl by enabling the concentration of usable floor space in urban centers. Sundling et al. [127] evaluated and compared four refurbishment approaches to find an economically feasible model using life cycle profit analysis and life cycle impact assessment, based on a study of six similar buildings constructed in Gothenburg (Sweden) in 1971. The findings showed that vertical extension promotes the energy-efficient renovation of buildings, and the combination of low energy and vertical extension has the highest return on investment and lowest environmental impact. Artes et al. [128] focused on the regeneration of city centers by identifying high proportions of the buildable area remaining on roofs (approximately 2500 buildings making up 800,000 square meters of buildable area in Barcelona, Spain) using two-dimensional panels and three-dimensional partitioning made of wood and steel. Their construction methods made it possible to undertake the upgrading of existing buildings and to provide, in at least seven cases, new high-quality homes that improved the quality of life for the community. Dind et al. [129] introduced the Workspace project aiming to develop a new prefabricated timber structure system tailored to the vertical extension of existing office buildings through a pilot project carried out in Lausanne (Switzerland). The results allowed the technical and architectural suitability of the system to be validated, particularly in terms of its typological flexibility and economic feasibility, with prefabrication, transportation, and assembly of large elements and a building in operation, in a dense urban context.

3. Wooden Additional Floor Construction

Additional floors (Figure 4) increase the building height and the number of building stories or change the shape of the roof, as one of the most effective ways to cover real estate development and renovation processes by increasing energy efficiency and functionality [25]. The benefits, challenges, and drawbacks of additional floor construction can be summarized as follows [23,24,25,26,27,28,130,131,132,133,134,135]:
(1)
As an efficient and environmentally friendly construction method, it provides beneficial development of the building stock and increases the income of property owners.
(2)
Renovation and upgrading of old building stock were more beneficial in terms of the carbon footprint than new construction and demolition. For example, Huuhka et al. [27] reported that renovation and upgrading works with additional floors have a 20% lower negative impact on the environment in terms of carbon footprint compared to new construction and demolition.
(3)
Additional floor construction provides short-term income to housing companies by selling the building rights or areas of additional floors. Revenues from additional floors could be used to cover the renovation cost of the old building.
(4)
Additional floors considerably increase the total floor area without significantly affecting the total energy consumption of the upgraded building.
(5)
As energy-efficient passive structures, additional floors can substantially improve the energy efficiency of existing buildings, especially if the upper floors have not been renovated for a long time.
(6)
Additional floors improve the appearance of the building and can have a substantial impact on the architectural impression.
(7)
Considering that the renovation process is a slow and uncomfortable process for the residents, the construction of an additional floor using prefabricated elements minimizes this discomfort of the building occupants and speeds up the process.
(8)
To minimize disturbance to residents, it makes sense to build wooden additional floors from box-like module elements. However, module elements are difficult to design and construct because the upper ceiling tile cannot usually be loaded, so the loading must be aligned with the load-bearing walls below the floor, which may be few in number.
(9)
To manage the renovation costs and use the insufficient autumn and winter capacities of the housing factories, wooden additional floor projects, especially during the winter months, face difficulties in the construction site conditions, especially in humidity control.
(10)
Additional floor construction, which not only ensures energy efficiency but also brings the existing building to modern standards, is a complicated process consisting of several stages mentioned below that are technically more difficult.
(11)
The socio-economic consequences of densification due to additional floors were brought to the agenda in several studies (e.g., [133,134,135]).
(12)
Increased use of infrastructure, green space, and common appliances can be considered as the drawbacks of additional floor construction.
The construction of a wooden additional floor can be divided into four main stages [29,125]: (i) The feasibility phase, (ii) project planning, (iii) implementation planning, and (iv) construction. During the feasibility phase, construction professionals and real estate sectors are contacted, and construction conditions of additional floors are evaluated. At the project planning stage, the project conditions, course, and scope of the project are determined. During implementation planning, steps are taken to enhance the construction plans and expand the building rights, allowing the construction of additional floors. The terms and conditions of the city plan change, building rights, and the company managing the property are among critical issues for this phase. As the final stage, the construction of wooden additional floors begins. Effective flow of information between residents and stakeholders and the appointment of a representative of the housing or real estate firm to join site meeting organizations and discuss suitable schedules for the construction process are important considerations at this stage.

4. Conclusions and Prospects

This entry aimed to map out, organize, and collate scattered information on the current state of the art, as well as benefits and challenges of wooden additional floor projects with their different stages, focusing on the case of Finland, and presents it in an accessible and understandable discourse for non-technical readers.
Endorsing positive market development, informing people about efficient energy use and energy savings from building refurbishments including the construction of additional floors, providing different forms of financial support for these sustainable practices, conducting more research and creating more investment, and encouraging new modes of energy contracts are actions that play important roles for future applications of additional floor construction.
In terms of both building construction technology and tendering procedures, wooden additional floor projects have great development potential. Especially with regard to construction technology, the use of prefabricated wooden elements, e.g., volumetric modular elements, can make construction faster and reduce construction-related disturbances, which is a major problem for building occupants, contributing to the diffusion of additional floor construction, as in Finland. For example, the experience and expertise gained in these projects, which have become widespread in the last ten years in the Tampere region of Finland, paved the way for further improvement in contract and technical-based issues [29,125].
All stages of wooden additional floor projects need dedication and investment, as well as advanced communication and collaboration between all relevant stakeholders and housing or real estate professionals. This entry will contribute to the increase in awareness of the construction of wooden additional floors, which has environmental, financial, energy-efficient, and aesthetic benefits in Finland and other countries.

Author Contributions

Conceptualization, H.E.I., A.S. and M.K.; methodology, H.E.I., A.S. and M.K.; software, H.E.I. and A.S.; formal analysis, H.E.I., A.S. and M.K.; investigation, H.E.I. and A.S.; data curation, H.E.I., A.S. and M.K.; writing—original draft preparation, H.E.I.; writing—review and editing, H.E.I., A.S. and M.K.; visualization, H.E.I. and A.S.; supervision, A.S. and M.K.; project administration, A.S. and M.K.; All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Not applicable.

Conflicts of Interest

The authors declare no conflict of interest.

Entry Link on the Encyclopedia Platform

https://encyclopedia.pub/21629.

References

  1. European Commission. Energy Roadmap 2050 Impact Assessment and Scenario Analysis, Brussels. 2011. Available online: https://ec.europa.eu/energy/sites/ener/files/documents/roadmap2050_ia_20120430_en_0.pdf (accessed on 25 February 2022).
  2. Donoghue, H. 2050 Energy Roadmap: Energy Policy & Innovation: Energy Roadmap 2050. Eur. Energy Clim. J. 2012, 2, 32–37. [Google Scholar]
  3. Kuittinen, M.; Häkkinen, T. Reduced carbon footprints of buildings: New Finnish standards and assessments. Build. Cities 2020, 1, 182–197. [Google Scholar] [CrossRef]
  4. Allard, I.; Nair, G.; Olofsson, T. Energy performance criteria for residential buildings: A comparison of Finnish, Norwegian, Swedish, and Russian building codes. Energy Build. 2021, 250, 111276. [Google Scholar] [CrossRef]
  5. Energy Policies of The International Energy Agency (IEA) Countries: Finland 2018 Review. 2018. Available online: https://www.connaissancedesenergies.org/sites/default/files/pdf-actualites/situation_energetique_de_la_finlande.pdf (accessed on 25 February 2022).
  6. European Commission. Long-Term Renovation Strategy 2020–2050 Finland, Report According to Article 2a of Directive (2010/31/EU) on the Energy Performance of Buildings, as Amended by Directive 2018/844/EU. 10 March 2020. Available online: https://ec.europa.eu/energy/sites/default/files/documents/fi_2020_ltrs_en.pdf (accessed on 25 February 2022).
  7. Simson, R.; Fadejev, J.; Kurnitski, J.; Kesti, J.; Lautso, P. Assessment of Retrofit Measures for Industrial Halls: Energy Efficiency and Renovation Budget Estimation. Energy Procedia 2016, 96, 124–133. [Google Scholar] [CrossRef]
  8. Kaasalainen, T.; Huuhka, S. Homogenous homes of Finland: ‘standard’ flats in non-standardized blocks. Build. Res. Inf. 2016, 44, 229–247. [Google Scholar] [CrossRef]
  9. Hirvonena, J.; Jokisaloa, J.; Heljo, J.; Kosonena, R. Towards the EU emissions targets of 2050: Optimal energy renovation measures of Finnish apartment buildings. Int. J. Sustain. Energy 2019, 38, 649–672. [Google Scholar] [CrossRef]
  10. The Housing Finance and Development Centre of Finland (ARA), The Suburban Innova Block of Flats Is Being Renovated into a Passive House. Available online: https://www.ara.fi/en-US/Housing_development/Development_projects/The_suburban_Innova_block_of_flats_is_be%2817681%29 (accessed on 25 February 2022).
  11. Soikkeli, A.; Sorri, L. A New Suburb Renovation Concept. Int. J. Archit. Environ. Eng. 2014, 8, 647–655. [Google Scholar]
  12. Soikkeli, A.; Hagan, H.; Karjalainen, M.; Koiso-Kanttila, J.; Kurnitski, J.; Viljakainen, M.; Hotakainen, T.; Jäntti, T.; Murtonen, N.; Sakki, R.; et al. Puun Mahdollisuudet Lähiöiden Korjauksessa. Oulu: Oulun Yliopisto, Arkkitehtuurin Osasto. Haettu Osoitteesta. 2011. Available online: https://www.oulu.fi/ark/tiedostot/puun_mahdollisuudet_lahioiden_korjauksissa_web.pdf (accessed on 25 February 2022). (In Finnish).
  13. The Finnish Timber of Council (Puuinfo). Available online: https://puuinfo.fi/?lang=enç (accessed on 25 February 2022).
  14. Huttunen, H.; Blomqvist, E.; Ellilä, E.; Hasu, E.; Perämäki, E.; Tervo, A.; Verma, I.; Ullrich, T.; Utriainen, J. The Finnish Townhouse as a Home. Starting Points and Interpretations. Habitat Components—Townhouse. Final Report. Aalto University Publication Series CROSSOVER 8/2017. Helsinki, Finland. 2017. Available online: https://aaltodoc.aalto.fi/bitstream/handle/123456789/30185/isbn9789526071220.pdf?sequence=1&isAllowed=y (accessed on 25 February 2022).
  15. United Nations Economic Commission for Europe United Nations Human Settlements Programme, Good Practices for Energy-Efficient Housing in the Unece Region, UNITED NATIONS, New York and Geneva. 2013. Available online: https://unece.org/fileadmin/DAM/hlm/documents/Publications/good.practices.ee.housing.pdf (accessed on 25 February 2022).
  16. Streimikiene, D.; Balezentis, T. Innovative Policy Schemes to Promote Renovation of Multi-Flat Residential Buildings and Address the Problems of Energy Poverty of Aging Societies in Former Socialist Countries. Sustainability 2019, 11, 2015. [Google Scholar] [CrossRef]
  17. Paiho, S.; Abdurafikov, R.; Hoang, H.; Castell-Rüdenhausen, M.Z.; Hedman, Å.; Kuusisto, J. Business Aspects of Energy Efficient Renovations of Sovietera Residential Districts A Case Study from Moscow, VTT Technology 154 ISSN-L 2242-1211 ISSN 2242-122X (Online), VTT Technical Research Centre of Finland, Espoo, Finland. 2014. Available online: https://www.vttresearch.com/sites/default/files/pdf/technology/2014/T154.pdf (accessed on 25 February 2022).
  18. Official Statistics of Finland (OSF). Homeowners and Housing Companies Repaired by EUR 6.0 Billion in 2019. 2019. Available online: http://www.stat.fi/til/kora/2019/01/kora_2019_01_2020-06-11_tie_001_fi.html%20 (accessed on 25 February 2022).
  19. Soikkeli, A.; Sorri, L. A New Suburb Renovation Concept. In Proceedings of the ICAE 2014: XII International Conference on Architectural Engineering, Copenhagen, Denmark, 12–13 June 2014; International Science Index 90; World Academy of Science, Engineering and Technology: Paris, France, 2014; pp. 636–644. [Google Scholar]
  20. KTI Finland. The Finnish Property Market. 2019. Available online: https://kti.fi/wp-content/uploads/The-Finnish-Property-Market-2019.pdf (accessed on 25 February 2022).
  21. Farahani, A.S. Maintenance, Renovation and Energy Efficiency in the Swedish Multi-Family Housing Market; The Division of Building Services Engineering, Chalmers University of Technology: Gothenburg, Sweden, 2017; Available online: https://core.ac.uk/download/pdf/198056482.pdf (accessed on 25 February 2022).
  22. Ferrante, A.; Prati, D.; Fotopoulou, A. Triple A-Reno: Attractive, Acceptable and Affordable Deep Renovation by a Consumers Orientated and Performance Evidence Based Approach. In WP4–Task 4.2 Analysis and Design of the Business Module; Huygen Installatie Adviseurs: Maastricht, The Netherlands, 2018. [Google Scholar]
  23. Soikkeli, A.; Sorri, L.; Koiso-Kanttila, J. New Concept for User-Orientated Suburb Renovation. In Proceedings of the World SB14, Barcelona, Spain, 28–30 October 2014; pp. 1–7. [Google Scholar]
  24. Soikkeli, A. Additional floors in old apartment blocks. Energy Procedia 2016, 96, 815–823. [Google Scholar] [CrossRef]
  25. Cronhjort, A.; Soikkeli, T.; Tulamo, T.; Junnonen, J. Urban Densification in Finland: Infill Development And Building Extensions With Timber Based Solutions. WIT Trans. Ecol. Environ. 2015, 193, 319–330. [Google Scholar]
  26. Karjalainen, M.; Ilgın, H.E.; Metsäranta, L.; Norvasuo, M. Residents’ Attitudes towards Wooden Facade Renovation and Additional Floor Construction in Finland. Int. J. Environ. Res. Public Health 2021, 18, 12316. [Google Scholar] [CrossRef] [PubMed]
  27. Huuhka, S.; Vainio, T.; Moisio, M.; Lampinen, E.; Knuuttinen, M.; Bashmakov, S.; Köliö, A.; Lahdensivu, J.; Ala-Kotila, P.; Lahdenperä, P. To Demolish or to Repair? Carbon Footprint Impacts, Life Cycle Costs and Steering Instruments, Publications of the Ministry of the Environment 2021:9. Built Environment. 2021. Available online: https://julkaisut.valtioneuvosto.fi/bitstream/handle/10024/162862/YM_2021_9.pdf?sequence=4&isAllowed=y (accessed on 25 February 2022).
  28. Bojić, M.; Miletić, M.; Malešević, J.; Djordjević, S.; Cvetković, D. Influence of additional storey construction to space heating of a residential building. Energy Build. 2012, 54, 511–518. [Google Scholar] [CrossRef]
  29. Karjalainen, M.; Ilgın, H.E.; Somelar, D. Wooden Additional Floors in Old Apartment Buildings: Perspectives of Housing and Real Estate Companies from Finland. Buildings 2021, 11, 316. [Google Scholar] [CrossRef]
  30. The National Building Code of Finland—Structural Fire Safety, Decree of the Ministry of the Environment. 2017. Available online: https://ym.fi/en/the-national-building-code-of-finland (accessed on 25 February 2022).
  31. Green, M. The Case for Tall Buildings: How Mass Timber Offers a Safe, Economical, and Environmentally Friendly Alternative for Tall Building Structures; MGB Architecture and Design: Vancouver, BC, Canada; Toronto, ON, Canada, 2012. [Google Scholar]
  32. Myers, F.; Fullera, R.; Crawford, R.H. The Potential to Reduce the Embodied Energy in Construction through the Use of Renewable Materials. In Proceedings of the ASA2012: The 46th Annual Conference of the Architectural Science Association (Formerly ANZAScA)—Building on Knowledge: Theory and Practice, Gold Coast, Australia, 14–16 November 2012. [Google Scholar]
  33. Construction Industry Progress towards Sustainability with Renewable Materials. Recycling Magazine. 2020. Available online: https://www.recycling-magazine.com/2020/04/14/construction-industry-progress-towards-sustainability-with-renewablematerials/ (accessed on 25 February 2022).
  34. Lammert, L. Circular Economy in Architecture—Sustainable Principles for Future Design. Master’s Thesis, Oulu School of Architecture, Faculty of Technology, University of Oulu, Oulu, Finland, 2018. Available online: https://figbc.fi/wpcontent/uploads/sites/4/2020/05/nbnfioulu-201811233096.pdf (accessed on 25 February 2022).
  35. Robati, M.; Oldfield, P.; Nezhad, A.A.; Carmichael, D.G.; Kuru, A. Carbon value engineering: A framework for integrating embodied carbon and cost reduction strategies in building design. Build. Environ. 2021, 192, 107620. [Google Scholar] [CrossRef]
  36. Hart, J.; D’Amico, B.; Pomponi, F. Whole-life embodied carbon in multistory buildings: Steel, concrete and timber structures. J. Ind. Ecol. 2021, 25, 403–418. [Google Scholar] [CrossRef]
  37. Soikkeli, A. Possibilities in the Renovation of Suburban Apartment Buildings. Case: Porvoonportti. In Improving the Quality of Suburban Building Stock; COST Action TU0701; Unifepress: Ferrara, Italy, 2012; pp. 127–140. [Google Scholar]
  38. Churkina, G.; Organschi, A.; Reyer, C.P.O.; Ruff, A.; Vinke, K.; Liu, Z.; Reck, B.K.; Graedel, T.E.; Schellnhuber, H.J. Buildings as a global carbon sink. Nat. Sustain. 2020, 3, 269–276. [Google Scholar] [CrossRef]
  39. Franzini, F.; Toivonen, R.; Toppinen, A. Why Not Wood? Benefits and Barriers of Wood as a Multistory Construction Material: Perceptions of Municipal Civil Servants from Finland. Buildings 2018, 8, 159. [Google Scholar] [CrossRef]
  40. Geng, A.; Yang, H.; Chen, J.; Hong, Y. Review of carbon storage function of harvested wood products and the potential of wood substitution in greenhouse gas mitigation. For. Policy Econ. 2017, 85, 192–200. [Google Scholar] [CrossRef]
  41. Hafner, A.; Schäfer, S. Comparative LCA study of different timber and mineral buildings and calculation method for substitution factors on building level. J. Clean. Prod. 2017, 167, 630–642. [Google Scholar] [CrossRef]
  42. Dong, Y.; Qin, T.; Zhou, S.; Huang, L.; Bo, R.; Guo, H.; Yin, X. Comparative Whole Building Life Cycle Assessment of Energy Saving and Carbon Reduction Performance of Reinforced Concrete and Timber Stadiums—A Case Study in China. Sustainability 2020, 12, 1566. [Google Scholar] [CrossRef]
  43. Bergman, R.; Puettmann, M.; Taylor, A.; Skog, K.E. The Carbon Impacts of Wood Products. For. Prod. J. 2014, 64, 220–231. [Google Scholar] [CrossRef]
  44. Pierobon, F.; Huang, M.; Simonen, K.; Ganguly, I. Environmental benefits of using hybrid CLT structure in midrise nonresidential construction: An LCA based comparative case study in the U.S. Pacific Northwest. J. Build. Eng. 2019, 26, 100862. [Google Scholar] [CrossRef]
  45. Ritter, M.; Skog, K.; Bergman, R. Science Supporting the Economic and Environmental Benefits of Using Wood and Wood Products in Green Building Construction; General Technical Report FPL-GTR-206; U.S. Department of Agriculture, Forest Service, Forest Products Laboratory: Madison, WI, USA, 2011; pp. 1–9. [Google Scholar]
  46. Wang, L.; Toppinen, A.; Juslin, H. Use of wood in green building: A study of expert perspectives from the UK. J. Clean. Prod. 2014, 65, 350–361. [Google Scholar] [CrossRef]
  47. Rinne, R.; Ilgın, H.E.; Karjalainen, M. Comparative Study on Life-Cycle Assessment and Carbon Footprint of Hybrid, Concrete and Timber Apartment Buildings in Finland. Int. J. Environ. Res. Public Health 2022, 19, 774. [Google Scholar] [CrossRef] [PubMed]
  48. Skullestad, J.L.; Bohne, R.A.; Lohne, J. High-rise Timber Buildings as a Climate Change Mitigation Measure—A Comparative LCA of Structural System Alternatives. Energy Procedia 2016, 96, 112–123. [Google Scholar] [CrossRef]
  49. CWC. Energy and the Environment in Residential Construction; Sustainable Building Series No.1; Canadian Wood Council: Ottawa, ON, Canada, 2007; Available online: https://cwc.ca/wp-content/uploads/publications-Energy-and-the-Environment.pdf (accessed on 25 February 2022).
  50. European Commission. A Sustainable Bioeconomy for Europe: Strengthening the Connection between Economy, Society and the Environment; Publications Office of the European Union: Luxembourg, 2018. [Google Scholar]
  51. Liang, S.; Gu, H.; Bergman, R.; Kelley, S. Comparative life-cycle assessment of a mass timber building and concrete alternative. Wood Fiber Sci. 2020, 52, 217–229. [Google Scholar] [CrossRef]
  52. Sandberg, K.; Orskaug, T.; Andersson, A. Prefabricated Wood Elements for Sustainable Renovation of Residential Building Façades. Energy Procedia 2016, 96, 756–767. [Google Scholar] [CrossRef]
  53. Gustavsson, L.; Joelsson, A.; Sathre, R. Life cycle primary energy use and carbon emission of an eight-storey wood-framed apartment building. Energy Build. 2010, 42, 230–242. [Google Scholar] [CrossRef]
  54. Jussila, J.; Lähtinen, K. Effects of institutional practices on delays in construction—Views of Finnish homebuilder families. Housing Stud. 2020, 35, 1167–1193. [Google Scholar] [CrossRef]
  55. Onyszkiewicz, J.; Sadowski, K. Proposals for the revitalization of prefabricated building facades in terms of the principles of sustainable development and social participation. J. Build. Eng. 2022, 46, 103713. [Google Scholar] [CrossRef]
  56. Werner, F.; Taverna, R.; Hofer, P.; Richter, K. Carbon pool and substitution effects of an increased use of wood in buildings in Switzerland: First estimates. Ann. For. Sci. 2005, 62, 889–902. [Google Scholar] [CrossRef]
  57. Kutnar, A.; Hill, C. Life Cycle Assessment—Opportunities for Forest Products Sector. Bioprod. Bus. 2017, 2, 52–64. [Google Scholar]
  58. Bergman, R.D.; Falk, R.H.; Gu, H.; Napier, T.R.; Meil, J. Life-Cycle Energy and GHG Emissions for New and Recovered Softwood Framing Lumber and Hardwood Flooring Considering End-of-Life Scenarios; Research Paper FPL-RP-672; U.S. Department of Agriculture, Forest Service, Forest Products Laboratory: Madison, WI, USA, 2013; p. 35. [Google Scholar]
  59. Karjalainen, M.; Ilgın, H.E. The Change over Time in Finnish Residents’ Attitudes towards Multi-Story Timber Apartment Buildings. Sustainability 2021, 13, 5501. [Google Scholar] [CrossRef]
  60. Jagarajan, R.; Abdullah Mohd Asmoni, M.N.; Mohammed, A.H.; Jaafar, M.N.; Lee Yim Mei, J.; Baba, M. Green retrofitting—A review of current status, implementations and challenges. Renew. Sustain. Energy Rev. 2017, 67, 1360–1368. [Google Scholar] [CrossRef]
  61. Östman, B. National Fire Regulations for the Use of Wood in Buildings—Worldwide Review 2020. Wood Mater. Sci. Eng. 2021, 1–4. [Google Scholar] [CrossRef]
  62. Kincelova, K.; Boton, C.; Blanchet, P.; Dagenais, C. Fire Safety in Tall Timber Building: A BIM-Based Automated Code-Checking Approach. Buildings 2020, 10, 121. [Google Scholar] [CrossRef]
  63. Xu, H.; Pope, I.; Gupta, V.; Cadena, J.; Carrascal, J.; Lange, D.; McLaggan, M.S.; Mendez, J.; Osorio, A.; Solarte, A.; et al. Large-scale compartment fires to develop a self-extinction design framework for mass timber—Part 1: Literature review and methodology. Fire Saf. J. 2022, 128, 103523. [Google Scholar] [CrossRef]
  64. Östman, B. Fire Safety in Timber Buildings—Technical Guideline for Europe; SP Technical Research Institute of Sweden: Stockholm, Sweden, 2010; p. 19. [Google Scholar]
  65. Östman, B.; Brandon, D.; Frantzich, H. Fire Safety Engineering in Timber Buildings. Fire Saf. J. 2017, 91, 11–20. [Google Scholar] [CrossRef]
  66. Su, L.; Wu, X.; Zhang, X.; Huang, X. Smart performance-based design for building fire safety: Prediction of smoke motion via AI. J. Build. Eng. 2021, 43, 102529. [Google Scholar] [CrossRef]
  67. Siddiqui, A.A.; Ewer, J.A.; Lawrence, P.J.; Galea, E.R.; Frost, I.R. Building Information Modelling for performance-based Fire Safety Engineering analysis—A strategy for data sharing. J. Build. Eng. 2021, 42, 102794. [Google Scholar] [CrossRef]
  68. Qiu, J.; Anwar Orabi, M.; Usmani, A.; Li, G. A computational approach for modelling composite slabs in fire within OpenSees framework. Eng. Struct. 2022, 255, 113909. [Google Scholar] [CrossRef]
  69. Liu, K.; Chen, W.; Ye, J.; Jiang, J. Full-scale fire and post earthquake fire experiments of CFS walls with new configurations. Structures 2022, 35, 706–721. [Google Scholar] [CrossRef]
  70. Medved, S. Buildings Fires and Fire Safety. In Building Physics; Springer International Publishing: Berlin/Heidelberg, Germany, 2021; pp. 407–451. [Google Scholar] [CrossRef]
  71. Liu, J.; Fischer, E.C. Review of large-scale CLT compartment fire tests. Construct. Build. Mater. 2022, 318, 126099. [Google Scholar] [CrossRef]
  72. Gasparri, E. 9—Unitized Timber Envelopes: The future generation of sustainable, high-performance, industrialized facades for construction decarbonization. In Woodhead Publishing Series in Civil and Structural Engineering, Rethinking Building Skins; Gasparri, E., Brambilla, A., Lobaccaro, G., Goia, F., Andaloro, A., Sangiorgio, A., Eds.; Woodhead Publishing: Cambridge, UK, 2022; pp. 231–255. [Google Scholar] [CrossRef]
  73. Tian, F.; Xu, D.; Xu, X. Synergistic Effect of APP and TBC Fire-Retardants on the Physico-Mechanical Properties of Strandboard. Materials 2022, 15, 435. [Google Scholar] [CrossRef]
  74. Buchanan, A.H.; Östman, B.; Frangi, A. Fire Resistance of Timber Structures; NIST White Paper: Washington, DC, USA, 2014. [Google Scholar]
  75. Caniato, M.; Bettarello, F.; Ferluga, A.; Marsich, L.; Schmid, C.; Fausti, P. Thermal and acoustic performance expectations on timber buildings. Build, Acoust. 2017, 24, 219–237. [Google Scholar] [CrossRef]
  76. Asdrubali, F.; Ferracuti, B.; Lombardi, L.; Guattari, C.; Evangelisti, L.; Grazieschi, G. A review of structural, thermo-physical, acoustical, and environmental properties of wooden materials for building applications. Build. Environ. 2017, 114, 307–332. [Google Scholar] [CrossRef]
  77. Olsson, L. Moisture safety in CLT construction without weather protection—Case studies, literature review and interviews. E3S Web Conf. 2020, 172, 10001. [Google Scholar] [CrossRef]
  78. Mjörnell, K.; Olsson, L. Moisture Safety of Wooden Buildings—Design, Construction and Operation. J. Sustain. Architect. Civil Eng. 2019, 24, 29–35. [Google Scholar] [CrossRef]
  79. Renner, J.S.; Mensah, R.A.; Jiang, L.; Xu, Q.; Das, O.; Berto, F. Fire Behavior of Wood-Based Composite Materials. Polymers 2021, 13, 4352. [Google Scholar] [CrossRef]
  80. Robert, J.; Bush, P.A.A. Changes and Trends in the Pallet Industry: Alternative Materials and Industry Structure. Memphis. Hardwood Mark. Rep. 1998, LXXVI, 11–14. [Google Scholar]
  81. Trouy, M.C.; Triboulot, P. Materiau bois: Structure et caractéristiques. Technol. Ingénieur Constr. Bois 2019, 253, 11–18. [Google Scholar] [CrossRef]
  82. Upton, B.; Miner, R.; Spinney, M.; Heath, L.S. The greenhouse gas and energy impacts of using wood instead of alternatives in residential construction in the United States. Biomass Bioenergy 2008, 32, 1–10. [Google Scholar] [CrossRef]
  83. Fast, P.; Jackson, R. A Case Study for Tall Timber. Struct. Mag. 2017, 50–52. [Google Scholar]
  84. Gohlich, R.; Erochko, J.; Woods, J.E. Experimental testing and numerical modelling of a heavy timber moment-resisting frame with ductile steel links. Earthq. Eng. Struct. Dynam. 2018, 47, 1460–1477. [Google Scholar]
  85. Andreolli, M.; Piazza, M.; Tomasi, R.; Zandonini, R. Ductile moment-resistant steel–timber connections. Proc. Inst. Civil Eng. Struct. Build. 2011, 164, 65–78. [Google Scholar] [CrossRef]
  86. Li, Z.; Wang, X.; He, M. Experimental and analytical investigations into lateral performance of cross-laminated timber (CLT) shear walls with different construction methods. J. Earthq. Eng. 2020, 1–23. [Google Scholar] [CrossRef]
  87. Yang, R.; Li, H.; Lorenzo, R.; Ashraf, M.; Sun, Y.; Yuan, Q. Mechanical behaviour of steel timber composite shear connections, Construct. Build. Mater. 2020, 258, 119605. [Google Scholar] [CrossRef]
  88. Iqbal, A. Developments in Tall Wood and Hybrid Buildings and Environmental Impacts. Sustainability 2021, 13, 11881. [Google Scholar] [CrossRef]
  89. Yang, X.; Tang, X.; Ma, L.; Sun, Y. Plastic composite sound insulation performance of structural wood wall integrated with wood. J. Bioresour. Bioprod. 2019, 4, 115–122. [Google Scholar] [CrossRef]
  90. Zhang, Y.; Xie, L. Inspection and Evaluation of Wooden Frame Constructions; Chinese Academy of Forestry: Beijing, China, 2011. [Google Scholar]
  91. Ding, Y.; Zhang, Y.; Wang, Z.; Gao, Z.; Zhang, T.; Huang, X. Vibration test and comfort analysis of environmental and impact excitation for wooden floor structure. Bioresources 2020, 15, 8212–8234. [Google Scholar] [CrossRef]
  92. Kankovsky, A.; Dedic, M. Wood flooring in combination with underfloor heating systems. IOP Conf. Ser. Mater. Sci. Eng. 2021, 1203, 22043. [Google Scholar] [CrossRef]
  93. Sun, J.; Tu, K.; Büchele, S.; Koch, S.M.; Ding, Y.; Ramakrishna, S.N.; Stucki, S.; Guo, H.; Wu, C.; Keplinger, T.; et al. Functionalized wood with tunable tribopolarity for efficient triboelectric nanogenerators. Matter 2021, 4, 3049–3066. [Google Scholar] [CrossRef]
  94. Song, Y.; Wang, H.B.; Cheng, X.L.; Li, G.K.; Chen, X.X.; Chen, H.T.; Miao, L.M.; Zhang, X.S.; Zhang, H.X. High-efficiency selfcharging smart bracelet for portable electronics. Nano Energy 2019, 55, 29–36. [Google Scholar] [CrossRef]
  95. Parida, K.; Xiong, J.Q.; Zhou, X.R.; Lee, P.S. Progress on triboelectric nanogenerator with stretchability, selfhealability and bio-compatibility. Nano Energy 2019, 59, 237–257. [Google Scholar] [CrossRef]
  96. Hao, S.F.; Jiao, J.Y.; Chen, Y.D.; Wang, Z.L.; Cao, X. Natural wood-based triboelectric nanogenerator as self-powered sensing for smart homes and floors. Nano Energy 2020, 75, 104957. [Google Scholar] [CrossRef]
  97. Chandrasekhar, A.; Vivekananthan, V.; Khandelwal, G.; Kim, W.J.; Kim, S.J. Green energy from working surfaces: A contact electrification-enabled data theft protection and monitoring smart table. Mater. Today Energy 2020, 18, 100544. [Google Scholar] [CrossRef]
  98. Tulonen, L.; Karjalainen, M.; Ilgın, H.E. Tall Wooden Residential Buildings in Finland: What Are the Key Factors for Design and Implementation? IntechOpen: London, UK, 2021. [Google Scholar]
  99. Zwerger, K. Recognizing the Similar and Thus Accepting the Other: The European and Japanese Traditions of Building with Wood. J. Tradit. Build. Archit. Urban. 2021, 2, 305–317. [Google Scholar] [CrossRef]
  100. Ilgın, H.E.; Karjalainen, M.; Koponen, O. Dovetailed Massive Wood Board Elements for Multi-Story Buildings. In Proceedings of the LIVENARCH VII Livable Environments & Architecture 7th International Congress OTHER ARCHITECT/URE(S), Trabzon, Turkey, 28–30 September 2021; Volume I, pp. 47–60. [Google Scholar]
  101. Yusof, N.M.; Tahir, P.M.; Lee, S.H.; Khan, M.A.; James, R.M.S. Mechanical and physical properties of Cross-Laminated Timber made from Acacia mangium wood as function of adhesive types. J. Wood Sci. 2019, 65, 20. [Google Scholar] [CrossRef]
  102. Karjalainen, M.; Ilgın, H.E.; Yli-Äyhö, M.; Soikkeli, A. Complementary Building Concept: Wooden Apartment Building: The Noppa toward Zero Energy Building Approach; IntechOpen: London, UK, 2021. [Google Scholar]
  103. Li, M.; Zhang, S.; Gong, Y.; Tian, Z.; Ren, H. Gluing Techniques on Bond Performance and Mechanical Properties of Cross- Laminated Timber (CLT) Made from Larix kaempferi. Polymers 2021, 13, 733. [Google Scholar] [CrossRef]
  104. Ilgın, H.E.; Karjalainen, M. Preliminary Design Proposals for Dovetail Wood Board Elements in Multi-Story Building Construction. Architecture 2021, 1, 56–68. [Google Scholar] [CrossRef]
  105. Bahrami, A.; Nexén, O.; Jonsson, J. Comparing Performance of Cross-Laminated Timber and Reinforced Concrete Walls. Int. J. Appl. Mech. Eng. 2021, 26, 28–43. [Google Scholar] [CrossRef]
  106. Ilgın, H.E.; Karjalainen, M.; Koponen, O. Various Geometric Configuration Proposals for Dovetail Wooden Horizontal Structural Members in Multistory Building Construction; IntechOpen: London, UK, 2022. [Google Scholar]
  107. Sun, Z.; Chang, Z.; Bai, Y.; Gao, Z. Effects of working time on properties of a soybean meal-based adhesive for engineered wood flooring. J. Adhes. 2021, 1–20. [Google Scholar] [CrossRef]
  108. Karjalainen, M.; Ilgın, H.E. A Statistical Study on Multi-Story Timber Residential Buildings (1995–2020) in Finland. In Proceedings of the LIVENARCH VII Livable Environments & Architecture 7th International Congress OTHER ARCHITECT/URE(S), Trabzon, Turkey, 28–30 September 2021; Volume I, pp. 82–94. [Google Scholar]
  109. Ilgın, H.E.; Karjalainen, M.; Koponen, O. Review of the Current State-of-the-Art of Dovetail Massive Wood Elements; IntechOpen: London, UK, 2021. [Google Scholar]
  110. Aaltonen, A.; Hurmekoski, E.; Korhonen, J. What about Wood?—“Nonwood” Construction Experts’ Perceptions of Environmental Regulation, Business Environment, and Future Trends in Residential Multistory Building in Finland. For. Prod. J. 2021, 71, 342–351. [Google Scholar] [CrossRef]
  111. Ilgın, H.E.; Karjalainen, M. Perceptions, Attitudes, and Interest of Architects in the Use of Engineered Wood Products for Construction: A Review; IntechOpen: London, UK, 2021. [Google Scholar]
  112. Roos, A.; Woxblom, L.; McCluskey, D. The influence of architects and structural engineers on timber in construction—Perceptions and roles. Silva Fenn. 2010, 44, 871–884. [Google Scholar] [CrossRef]
  113. Karjalainen, M.; Ilgın, H.; Tulonen, L. Main Design Considerations and Prospects of Contemporary Tall Timber Apartment Buildings: Views of Key Professionals from Finland. Sustainability 2021, 13, 6593. [Google Scholar] [CrossRef]
  114. Hemström, K.; Gustavsson, L.; Mahapatra, K. The sociotechnical regime and Swedish contractor perceptions of structural frames. Constr. Manag. Econ. 2017, 35, 184–195. [Google Scholar]
  115. Karjalainen, M.; Ilgın, H.E.; Metsäranta, L.; Norvasuo, M. Suburban Residents’ Preferences for Livable Residential Area in Finland. Sustainability 2021, 13, 11841. [Google Scholar] [CrossRef]
  116. Markström, E.; Kuzman, M.K.; Bystedt, A.; Sandberg, D.; Fredriksson, M. Swedish architects view of engineered wood products in buildings. J. Clean. Prod. 2018, 181, 33–41. [Google Scholar] [CrossRef]
  117. Karjalainen, M.; Ilgın, H.E.; Metsäranta, L.; Norvasuo, M. Wooden Facade Renovation and Additional Floor Construction for Suburban Development in Finland; IntechOpen: London, UK, 2022. [Google Scholar]
  118. Ilgın, H.E.; Karjalainen, M.; Pelsmakers, S. Finnish architects’ attitudes towards multi-storey timber-residential buildings. Int. J. Build. Pathol. Adapt. 2021. ahead-of-print. [Google Scholar]
  119. Häkkänen, L.; Ilgın, H.E.; Karjalainen, M. The Current State of the Finnish Cottage Phenomenon: Perspectives of Experts. Buildings 2022, 12, 260. [Google Scholar] [CrossRef]
  120. Gold, S.; Rubik, F. Consumer attitudes towards timber as a construction material and towards timber frame houses—Selected findings of a representative survey among the German population. J. Clean. Prod. 2009, 17, 303–309. [Google Scholar] [CrossRef]
  121. Lähtinen, K.; Harju, C.; Toppinen, A. Consumers’ perceptions on the properties of wood affecting their willingness to live in and prejudices against houses made of timber. Wood Mater. Sci. Eng. 2019, 14, 325–331. [Google Scholar] [CrossRef]
  122. Kylkilahti, E.; Berghäll, S.; Autio, M.; Nurminen, J.; Toivonen, R.; Lähtinen, K.; Vihemäki, H.; Franzini, F.; Toppinen, A. A consumer-driven bioeconomy in housing? Combining consumption style with students’ perceptions of the use of wood in multi-story buildings. Ambio 2020, 49, 1943–1957. [Google Scholar] [CrossRef] [PubMed]
  123. Wang, Z.; Yin, T. Cross-Laminated Timber: A Review on Its Characteristics and an Introduction to Chinese Practices; IntechOpen: London, UK, 2021. [Google Scholar]
  124. Rahman, T.; Ashraf, M.; Ghabraie, K.; Subhani, M. Evaluating Timoshenko Method for Analyzing CLT under Out-of-Plane Loading. Buildings 2020, 10, 184. [Google Scholar] [CrossRef]
  125. Karjalainen, M.; Ilgın, H.E.; Somelar, D. Wooden Extra Stories in Concrete Block of Flats in Finland as an Ecologically Sensitive Engineering Solution, Ecological Engineering—Addressing Climate Challenges and Risks; IntechOpen: London, UK, 2021. [Google Scholar]
  126. Leskovar, V.Ž.; Nedelko, M.L.; Premrov, M. Building refurbishment by vertical extension with lightweight structural modules. In Proceedings of the 1st Latin American SDEWES Conference, Rio de Janeiro, Brazil, 28–31 January 2018. [Google Scholar]
  127. Sundling, R.; Blomsterberg, Å.; Landin, A. Enabling energy-efficient renovation: The case of vertical extension to buildings. Construct. Innov. 2019, 19, 2–14. [Google Scholar] [CrossRef]
  128. Artés, J.; Wadel, G.; Martí, N. Vertical Extension and Improving of Existing Buildings. Open Construct. Build. Technol. J. 2017, 11, 83–94. [Google Scholar] [CrossRef]
  129. Dind, A.; Lufkin, S.; Rey, E. A Modular Timber Construction System for the Sustainable Vertical Extension of Office Buildings. Designs 2018, 2, 30. [Google Scholar] [CrossRef]
  130. Janda, K.B. Building communities and social potential: Between and beyond organizations and individuals in commercial properties. Energy Policy 2014, 67, 48–55. [Google Scholar] [CrossRef]
  131. Mills, B.; Schleich, J. Residential energy-efficient technology adoption, energy conservation, knowledge, and attitudes: An analysis of European countries. Energy Policy 2012, 49, 616–628. [Google Scholar] [CrossRef]
  132. Nilsson, R. Vertical Extension of Buildings. Licentiate Thesis, Division of Construction Management, Lund University, Lund, Sweden, 2017. [Google Scholar]
  133. Turok, I. Deconstructing density: Strategic dilemmas confronting the post-apartheid city. Cities 2011, 28, 470–477. [Google Scholar] [CrossRef]
  134. Nabielek, K. Urban densification in The Netherlands: National spatial policy and empirical research of recent developments. In Proceedings of the 5th Conference of International Forum on Urbanism, Global Visions: Risks and Opportunities for the Urban Planet, National University of Singapore, Singapore, 24–26 February 2011. [Google Scholar]
  135. Quastel, N.; Moos, M.; Lynch, N. Sustainability-as-density and the return of the social: The case of Vancouver, British Columbia. Urban Geogr. 2021, 33, 1055–1084. [Google Scholar] [CrossRef]
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Figure 1. Wooden additional floor project examples: (a) (Image courtesy of Aino Hirvilammi, Eetu Salminen, and Joel Lehtola); (b) (Image courtesy of Risto Piirainen and Silja Suitiala).
Figure 1. Wooden additional floor project examples: (a) (Image courtesy of Aino Hirvilammi, Eetu Salminen, and Joel Lehtola); (b) (Image courtesy of Risto Piirainen and Silja Suitiala).
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Figure 2. Two-story-high wooden additional floor (Image courtesy of Petri Pettersson).
Figure 2. Two-story-high wooden additional floor (Image courtesy of Petri Pettersson).
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Figure 3. Additional floor project with wooden prefabricated units (Image courtesy of Simo Rasmussen).
Figure 3. Additional floor project with wooden prefabricated units (Image courtesy of Simo Rasmussen).
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Figure 4. Wooden additional floor project examples: (a) An example where the shape of the roof has changed (Image courtesy of Samu Rantanen, Elissa Helminen, and Linnea Lindberg); (b) an example where the shape of the roof has not changed (Image courtesy of Johanna Partanen, Laura Lamberg, and Riina Hagren).
Figure 4. Wooden additional floor project examples: (a) An example where the shape of the roof has changed (Image courtesy of Samu Rantanen, Elissa Helminen, and Linnea Lindberg); (b) an example where the shape of the roof has not changed (Image courtesy of Johanna Partanen, Laura Lamberg, and Riina Hagren).
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MDPI and ACS Style

Soikkeli, A.; Ilgın, H.E.; Karjalainen, M. Wooden Additional Floor in Finland. Encyclopedia 2022, 2, 578-592. https://0-doi-org.brum.beds.ac.uk/10.3390/encyclopedia2010038

AMA Style

Soikkeli A, Ilgın HE, Karjalainen M. Wooden Additional Floor in Finland. Encyclopedia. 2022; 2(1):578-592. https://0-doi-org.brum.beds.ac.uk/10.3390/encyclopedia2010038

Chicago/Turabian Style

Soikkeli, Anu, Hüseyin Emre Ilgın, and Markku Karjalainen. 2022. "Wooden Additional Floor in Finland" Encyclopedia 2, no. 1: 578-592. https://0-doi-org.brum.beds.ac.uk/10.3390/encyclopedia2010038

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