Perceptions, Attitudes, and Interests of Architects in the Use of Engineered Wood Products for Construction: A Review

Increased use of engineered wood products (EWPs) and thus decreasing share of non-biobased materials such as concrete reduces the impact of buildings on the climate by mitigating the primary energy use and greenhouse gas emissions in construction. A construction project includes many parameters, where the selection of construction material is one of the crucial decisions with its numerous criteria e.g. cost, strength, environmental impact. Furthermore, this complicated process includes different parties such as architects, engineers, contractors. Architects are among the key decision-makers in material selection, and their perceptions influence what they propose and hence an increase in wood construction. In literature, many studies have been conducted on the technological, ecological, economic aspects of EWPs, while limited studies are focusing on EWPs for construction from stakeholders’ perspective. In this chapter, architects’ attitudes towards the use of EWPs in buildings were scrutinized

Tall Wooden Residential Buildings in Finland: What Are the Key Factors for Design and Implementation?

This chapter examines tall residential buildings using engineered wood products (EWPs) in Finland. As specified in the National Building Code of Finland, ‘tall wooden building’ is defined as a structure with more than 8-story. Currently, there are two wooden residential buildings, 14-story Lighthouse Joensuu (2019) with laminated veneer lumber (LVL) structure and 13-story HOAS Tuuliniitty (under construction) with cross laminated timber (CLT) structure, that fit the definition above. This study analyses the phenomena associated with the design and implementation processes of these remarkable buildings, the starting points for the projects as well as the prospects of tall wooden housing in Finland through the case study method and interviews with the key actors in the projects. These cases are mapped with extremely detailed information, comprising a valuable source both for designers, engineers as well as developers. As a result, the current state-of-the-art and the critical factors influencing the design and implementation of these challenging sustainable projects in Finland have been identified. It is believed that this chapter will aid and direct key stakeholders in the construction industry in the sound planning and development of tall wooden residential projects in Finland

Review of the Current State-of-the-Art of Dovetail Massive Wood Elements

Engineered wood products (EWPs) have been progressively more being utilized in the construction industry as structural materials since the 1990s. In the content of EWPs, adhesives play an important role. However, because of their petroleum-based nature, adhesives contribute to toxic gas emissions such as formaldehyde and Volatile Organic Compounds, which are detrimental to the environment. Moreover, the frequent use of adhesives can cause other critical issues in terms of sustainability, recyclability, reusability, and further machining. In addition to this, metal connectors employed in EWPs harm their end-of-life disposal, reusability, and additional processing. This chapter is concentrating on dovetail massive wood elements (DMWE) as adhesive- and metal connector-free sustainable alternatives to commonly used EWPs e.g., CLT, LVL, MHM, Glulam. The dovetail technique has been a method of joinery mostly used in wood carpentry, including furniture, cabinets, log buildings, and traditional timber-framed buildings throughout its rich history. It is believed that this chapter will contribute to the uptake of DMWE for more diverse and innovative structural applications, thus the reduction in carbon footprint by increasing the awareness and uses of DMWE in construction

Complementary Building Concept: Wooden Apartment Building: The Noppa toward Zero Energy Building Approach

Increasing the construction of wooden apartment buildings has its place as part of preventing climate change. This chapter aims to explore the possibilities of expanding the construction of wooden apartment buildings on plots owned by the City of Helsinki in the Mellunkylä area by developing a series-produced wooden apartment building concept suitable for complementary construction—The Noppa concept. The sustainability of this approach is considered from the perspective of materials, construction methods, adaptability of the designed spaces, and housing design flexibility. In this study, the Noppa wooden apartment building concept with cross-laminated timber (CLT) elements has been developed varying in its facilities and architectural design features through architectural modeling programs to be used for complementary construction. The research findings are based on a theoretical approach that has not yet been practically tested but is proposed considering existing construction practices that need further investigation. It is believed that this chapter will contribute to the spread of wooden apartments to achieve a low-carbon economy as one of the key tools in tackling climate change problems. Particularly, proposed architectural design solutions will contribute to decarbonization of buildings as well as zero energy building (nZEB) approach

Space Efficiency in Tapered Super-Tall Towers

In modern skyscraper architecture, the preference for incorporating tapered building configurations is on the rise, constituting a prominent trend in the industry, particularly due to their structural and aerodynamic benefits. The efficient utilization of space is a critical consideration in the design of tapered skyscrapers, holding significant importance for sustainability. Nevertheless, the existing body of scholarly work falls short in providing an all-encompassing investigation into the space efficiency of super-tall towers featuring tapered configurations, despite their prevalent adoption. This research endeavors to rectify this notable void by undertaking an exhaustive examination of data derived from 40 case studies. The key findings are as follows: (1) average space efficiency was about 72%, with values fluctuating between a minimum of 55% and a maximum of 84%; (2) average ratio of core area to the gross floor area (GFA) registered about 26%, encompassing a spectrum ranging from 11% to 38%; (3) most tapered skyscrapers employed a central core design, primarily tailored for mixed-use purposes; (4) an outriggered frame system was the prevailing structural system, while composite materials were the most commonly used structural materials; and (5) significant differences in the influence of function and load-bearing systems on the space efficiency of tapered towers were not observed. The author anticipates that these results will offer valuable direction, particularly to architectural designers, as they work towards advancing the sustainable development of tapered skyscrapers

Süper yüksek binalarda taşıyıcı sistemin potensiyel ve sınırlılıkları: mimarlar için tasarım kılavuzu.

In the past, the forms used in design were restricted but currently freedom in the design of supertall buildings has significantly increased, along with a contemporary widening of the form spectrum in design. Owing to the advancements particularly in architectural design methods and innovations in computer technologies, today’s supertall buildings could be realized with exceedingly daring forms that are almost never found in their predecessors. Increasing demand for "iconic" supertall buildings in new urban developments - challenging race for inserting the most extraordinary tall building among big metropolis’ thorough the world in their urban silhouettes, and contemporary architect’s enthusiasm for creating unconventional building forms - has begun to define the state of the architecture of today’s skyscrapers. Contemporary approaches in supertall building design sometimes bring about exaggeration of aesthetic concern in architectural design, which can pose adverse outcomes in structural design because of the inadequacy or lack of an advance level of interdisciplinary collaboration, specifically between architectural and structural designers. In other words, abovementioned attitude may cause the problems in the structural design addressed after the architectural form articulation, which unavoidably limits the structural design role to solving the issue rather than handling the structural architectural design together. On the other hand, it must be known that the structural costs of tall buildings can constitute up to nearly 30% of the total construction cost and increase significantly with height. The architects of today who design supertall buildings must be aware of the fact that some forms, especially unconventional ones, could be put into practice with only certain types of structural systems in order to catch the feasibility and efficiency in structural, aerodynamic, technical and of course last but not least financial/economic concerns. Because of these reasons, the architects inevitably must have profound knowledge of potentials and limitations of supertall building structural systems. Consequently, today, the role of the architect in the development of supertall buildings’ form has become progressively a major concern. Such a role presents the architect with an even greater challenge to realize the conceptual ideas as not only visually pleasant, but also as viable from the structural and constructional points of view.Ph.D. - Doctoral Progra

Space Efficiency in Contemporary Supertall Residential Buildings

Space efficiency is one of the most important design considerations in any tall building, in terms of making the project viable. This parameter becomes more critical in supertall (300 m+) residential towers, to make the project attractive by offering the maximum usage area for dwellers. This study analyzed the space efficiency in contemporary supertall residential buildings. Data was collected from 27 buildings, using a literature survey and a case study method, to examine space efficiency and the main architectural and structural design considerations affecting it. The results of this research highlighted that: (1) central core was the most common type of design parameter; (2) prismatic forms were the most preferred building forms; (3) the frequent use of reinforced concrete was identified, compared to steel and composite; (4) the most common structural system was an outriggered frame system; (5) the space efficiency decreased as the building height increased, in which core planning played a critical role; (6) when building form groups were compared among themselves, no significant difference was found between their effects on space efficiency, and similar results were valid for structural systems. It is believed that this study will help and direct architects in the design and implementation of supertall residential projects

Use of aerodynamically favorable tapered form in contemporary supertall buildings

Today, supertall buildings can be constructed in unusual forms as a pragmatic reflection of advances in construction techniques and engineering technologies, together with advanced computational design tools for architectural design. As with many other buildings, architectural and practical principles play a crucial role in the form of a supertall building, where aerodynamic behavior shaped by wind-induced excitations also becomes a critical design input. Various methods are used to meet the functional needs of these towers and reduce excitations, including aerodynamic modification methods directly related to the building form. Tapered forms are one of the most frequently used and most effective methods in today's skyscrapers, which significantly affect architectural design. To date, no study has been conducted in the literature that provides an understanding of the interrelationships between tapered building forms and main planning criteria, considering the aerodynamic design concerns of the tapering effect in supertall buildings (≥300 m). This important issue is explored in this article with data gathered from 41 supertall case studies, considering location, function, structural system, and structural material as well as the aerodynamic taper effect. The main findings of the study highlighted the following: (1) Asia was where tapered towers were most favored, with a wider margin in all regions; (2) mixed-use was the most preferred function in selected supertall buildings with tapered form; (3) outriggered frame systems were mainly used; (4) tapered supertall cases were mostly built in composite; (5) the sample group included 17 cases that used the tapering effect with aerodynamic design concerns, some of which were accompanied by corner modifications. It is believed that this study will be a basic guide for design and construction professionals including architectural and structural designers, and contractors

The change over time in finnish residents’ attitudes towards multi-story timber apartment buildings

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 multistory 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.publishedVersionPeer reviewe

Wood Preservation Practices and Future Outlook : Perspectives of Experts from Finland

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 con-cepts; (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.publishedVersionPeer reviewe