The Ipê Building features a linear layout and is primarily structured with transverse frames made of MLC elements, which provide bracing in the shorter direction. A concrete core connected to the frames by longitudinal MLC beams ensures stability in the other direction. Vertical loads are transferred from the CLT and DLT slabs to the frames, which then transmit them to the reinforced concrete foundations. The frames have the distinctive feature of including one of their beams as a tied beam, which ensures greater structural lightness near the glass front façade.
DORMF + STRELKA
The United Nations (2019) projected that by 2050, there will be 2.5 billion new urban residents worldwide (in Brazil, it is estimated that 92.4% of the population will be urban), which will necessitate the production of a large volume of new housing units over the coming decades. At the same time, the study by Churkina et al. (2020) shows that, under a construction scenario similar to the current one (99.5% of buildings made of steel and concrete), the accumulated carbon emissions for producing these materials could reach 4.4 Gt of carbon to meet the global demand for new housing. This highlights the need for a paradigm shift in the construction industry. More optimistic scenarios have been proposed and studied, involving the use of engineered wood products (CLT and MLC) in new constructions to varying degrees. Based on life cycle analyses, it has been concluded that, in addition to significantly reducing carbon emissions through the large-scale adoption of wood, wooden buildings themselves could become true carbon reservoirs. Throughout their lifespan, they store the carbon sequestered by the wood during tree growth. Thus, wood construction emerges as an alternative with great environmental potential, particularly concerning carbon emissions. However, this requires proper forest management, certification programs, stringent environmental legislation and oversight, as well as appropriate measures to ensure durability and protection, aiming to produce and preserve structures with long lifespans. Indeed, according to Miotto (2009), using certified wood in structures is beneficial for the environment, considering that wood is a renewable, reusable material and an excellent carbon sink, meeting all fundamental requirements to mitigate the environmental impacts caused by construction activities. In this context, the study of new wooden construction typologies, particularly residential ones—given the significant demand for new urban housing—is essential to foster a broad debate between academia and society, aiming to move urgently toward the necessary paradigm shift
In this proposal, we present three multifamily building projects that make significant use of engineered wood structural systems and explore a possible configuration of a typical urban block, also incorporating commercial and community activities.
Our effort aims to achieve balance and beauty within the urban fabric. We believe in the importance of streets with high pedestrian activity, fostering the joy of unexpected encounters and all forms of social interaction. Our proposal is based on relatively small, porous, and interconnected urban blocks featuring avant-garde architecture. The project explores the interiority of the blocks, offering alternatives for faster, quieter, and more serene pathways while complementing the peripheral promenades, richly filled with shops and restaurants. A low-rise, linear construction connects the residential buildings, helping to shape legible spaces within the block while simultaneously providing areas for commercial and community activities, which we consider essential complements to housing. Above these, residents have access to abundant communal terraces for sunbathing and socializing. Vegetation plays an important role, serving not just a decorative purpose but as an integral part of the landscape, without overshadowing the fundamentally urban and active essence of the proposal.
Regarding architecture, the project respects the plasticity and specific material qualities of each building, emphasizing their expressiveness through subtle manipulations in the arrangement of façade elements. The layouts are flexible in essence, using façades not only for lighting, ventilation, and thermal and acoustic insulation (given the excellent thermal properties of CLT) but also as an integral part of the structural system, especially for the bracing of the buildings. The façades are also utilized as solutions for storage, worktables, and kitchen counters. The external CLT panels are protected by waterproof membranes and clad to enhance durability. Wet areas are arranged linearly, optimizing construction while leaving ample open zones for the main spaces of the apartments. This ensures flexibility, not only for unit layout changes but also for reconfigurations of entire floors if necessary, allowing the buildings to accommodate changes in use over a much longer period.
The three proposed buildings prioritize the use of mass timber structural elements, particularly glued laminated timber (GLT) and cross-laminated timber (CLT). Some common features of the buildings are:
Exterior Protection of CLT Panels: The external walls made of CLT panels are protected by waterproof membranes and clad with sawn wood slats, which are treated with natural preservatives or the shou sugi ban technique. This technique involves the superficial charring of the wood to increase its durability. These CLT walls contribute to the thermal and acoustic insulation of the buildings and, in some cases, assist the structural system, especially in bracing.
Protection Against Rising Damp: All wooden elements are protected from direct contact with the ground through the use of reinforced concrete foundations and connections made of metal components, which were not detailed at this stage of the project.
Non-Structural Interior Walls: These are composed of lightweight partition panels (aiming to achieve the desired architectural flexibility) structured with sawn timber studs or laminated veneer lumber (LVL). They include thermal and acoustic insulation within and are finished with OSB panels and gypsum boards.
Vertical Concrete Cores: The buildings feature reinforced concrete cores in the vertical circulation areas, aiming to create a barrier against fire propagation in escape routes. It is known that massive wood elements perform well structurally under fire conditions (Pinto, 2001), as the formation of a charred layer thermally insulates the interior, maintaining its structural properties intact and allowing fire resistance times to be predicted during the design phase. However, it is also true that wood is a flammable material, which makes it prudent to build protected escape routes. Lastly, it is worth noting that these concrete cores also significantly contribute to the bracing systems of the buildings.
