Norman Foster Foundation Kharkiv Housing Challenge - Blooming Towards the Sun

The Kharkiv Housing Challenge is an international architecture competition organized by Buildner and co-initiated by the Kharkiv City Council, the United Nations Economic Commission for Europe (UNECE), the Norman Foster Foundation, and Arup, aiming to transform damaged residential areas through modular and innovative solutions into safe, energy-efficient communities, with winning designs to be implemented and replicated to support the city's long-term recovery. The competition received 259 submissions from 53 countries, with only one First Prize, one Second Prize, and one Third Prize awarded. PILLS was awarded Second Prize, and was the only Chinese team among the winners of this international competition. - Background Kharkiv, an industrial city in northeastern Ukraine with a population of 1.4 million, is currently facing multiple challenges brought by the war, including risks to food security. The city has approximately 1,900 square kilometers of arable land, accounting for about 5.9% of Ukraine’s total arable land, and plays an important role in the country’s agricultural exports. As of September 18, 2024, the Russia–Ukraine conflict had lasted 936 days, and its profound impact on civilians continues. Amid ongoing uncertainty, people are being forced to adapt to living alongside war. The significance of post-war reconstruction extends beyond physical recovery; it is also a process of emotional and psychological healing. It involves restoring each individual’s sense of agency in life, as well as rebuilding collective confidence in the future. Reconstruction must reconnect dispersed families and communities, restore production, and revitalize everyday life. - Concept Generation Based on research and analysis of local communities in Kharkiv and the surrounding region, we identified a set of typical challenges faced by post-war communities and proposed a comprehensive reconstruction strategy that responds to multiple dimensions of need. Taking the community as the basic unit, the strategy integrates modular housing, vertical farming, public landscapes, and a community library. It addresses issues such as housing shortages caused by destroyed homes, dispersed communities, stalled agricultural production, employment difficulties, and psychological trauma. The goal is to rebuild a community with resilience and agency at the levels of architectural structure, socio-economic systems, and cultural psychology． The proposal restores building volumes through a self-supporting structural framework while introducing a prestressed steel strand system to reinforce the original precast concrete slab structure. The integration of the new and existing structures creates a continuous interstitial layer which, combined with the renovated façade, forms a vertical greenhouse. This layer buffers temperature fluctuations caused by changing weather conditions while providing abundant communal planting spaces. Sunflowers are cultivated on rooftop and gable-end farms, with crops collected via a vertical transport system and processed on designated production floors. Sunflower Roof: National Symbol in Reconstruction Ukraine is the world’s largest exporter of sunflower seeds and related processed products. As a national symbol, the sunflower holds not only agricultural and economic significance, but also cultural, ecological, and emotional value, representing prosperity, sunshine, and a spirit of optimism. However, due to the Russia–Ukraine conflict, Ukraine’s sunflower production has declined sharply, creating a significant gap in the market. In response, the design strategy introduces the concept of a “Sunflower Farm,” aiming to repair physical space while addressing the shortage in post-war agricultural production and conveying the Ukrainian people’s hope for the future and their longing for peace. The project uses sunflowers as a medium to integrate a vertical farming system into architectural restoration, reconnecting nature, community, and production activities. Sunflowers grow in rooftop and gable farms. Mature crops are collected through a vertical transport system to a dedicated processing layer for threshing and preliminary pressing, continuing Ukraine's industrial logic of "local pressing, exporting sunflower oil and meal." Meanwhile, sunflower by-products such as acoustic panels and husk boards can be fully utilized, directly serving architectural restoration and spatial construction, forming a local closed loop of agriculture-processing-construction. The sunflower processing level acts as a buffer between the rooftop farms and the residential areas. It supports the operation of the farms while also providing a shared setting for collective work and interaction within the community. Over time, the “Sunflower Farm” will become an important place for resident engagement, strengthening community cohesion and encouraging collective development and shared emotional rebuilding. Airspace: Structural Repair & Climate Interface We adopt a self-supporting structural frame combined with a prestressed steel strand system to reinforce and extend the volume of the original building, creating a continuous vertical air cavity between the new structure and the remnants of the existing concrete slabs. This cavity not only achieves structural integration between the old and the new but also generates a microclimatic space capable of buffering climate fluctuations and regulating temperature. Together with the renovated exterior facade system, this cavity forms a vertical greenhouse that mitigates temperature variations caused by weather changes while providing ample public space for diverse activities—such as sunflower cultivation and community agricultural practices—allowing structural rehabilitation and ecological regeneration to unfold simultaneously within the same spatial dimension. Modular System: Adaptive Structure and Functional Regeneration The buildings on site exhibit varying degrees of damage—some have only their facades affected, while others have experienced complete collapse of their structure and overall volume. Based on the original precast concrete slab structure, the restoration strategy introduces a modular system that offers a flexible, "menu-style" selection of options. Through a layered reconstruction approach tailored to different levels of damage, the scheme not only maintains overall harmony and unity but also endows each building with its own distinct public spaces and visual character. Following extensive research, the proposal establishes prefabricated assembly and integrated modules as the foundational logic of the modular system. A. Integrated Prefabrication The production of prefabricated building components within a controlled manufacturing environment offers significant advantages. It not only reduces on-site labor demand and construction time, but also allows factories to maintain optimal working conditions year-round. This ensures higher precision in component fabrication and improves the overall quality of the construction system. B. Modular Construction Modular construction refers to the use of independent three-dimensional units or partially completed components that can be expanded spatially through stacking or side-by-side connection. As one of the most complete forms of prefabricated construction, modular building systems typically allow up to 95% of construction and interior finishing to be completed in the factory. The proposed modular system consists of four primary categories: façade balcony units, residential units, vertical agriculture units, and prefabricated shelter units. Depending on the extent of structural damage and functional requirements, each building can flexibly select and combine components from these four module types, establishing a clear and adaptable pathway for reconstruction. Taking Building 82 as an example, this structure is among the most severely damaged buildings on the site. As a twin-tower configuration, the two volumes were originally arranged in mirror symmetry. However, in one of the towers, the upper half of the building and its vertical circulation system were severely damaged by an explosion. In response, and following overall structural reinforcement, modules E1–E3 are introduced to restore the building volume and residential units, while modules C1–C2 reconstruct the stair cores. Modules A1–B4 are applied to renew the façade design, and modules D1–D2 are incorporated to create a vertical sunflower farm, adding ecological functionality to the building. This strategy not only effectively addresses the extensive damage to Building 82 but also provides a replicable framework for the rehabilitation of other damaged buildings on the site. Notably, on the more severely damaged side, the remaining lower portion of Building 82 forms a recessed spatial void. The proposal retains this space and transforms it into a community “Valley Library,” creating a three-dimensional public interlayer that connects the new and existing residential units while revealing the distinctive aesthetic created by the interweaving of old and new structures. Through an assessment of the damage conditions of the other four buildings on the site, corresponding module combinations and reconstruction pathways were developed for each. At the façade level, modular compositions introduce a strong horizontal rhythm and cadence. The iconic sunflowers gleam across the development, forming what appears to be a continuous golden ribbon that ties the entire community together. Community Rebuilding: Emotional Connection in Spatial Restoration This prolonged state of emergency has profoundly reshaped everyday life. Many people now face the loss of homes, interrupted education, agricultural contamination, and economic stagnation. The sustained psychological pressure has left deep and lasting impacts on the community. The significance of post-war reconstruction lies not only in physical recovery, but also in emotional healing—restoring each individual’s sense of agency in life while rebuilding collective confidence in the future. Reconstruction must reconnect dispersed families and communities, restore production, and revitalize daily life. We are committed to recycling and repurposing post-war construction debris, transforming it into a series of multifunctional public spaces. These spaces not only enhance the public landscape but also provide the community with libraries, greenhouses, playgrounds, and other essential venues. Serving both as memorials to history and as sites of new beginnings, these spaces evolve over time—as vegetation gradually thrives amidst the ruins, the memories of war intertwine with the new lives of residents. Through community activities and shared experiences, these spaces become vessels for remembrance and commemoration, while simultaneously fostering collective healing and social recovery, imbuing the ruins with renewed meaning and hope. The proposal also reconstructs the existing commercial district using modules E1–E3, while introducing underground shelters using Module F. These shelters are integrated with the commercial spaces: in times of peace they serve as storage areas for ground-level shops, and in emergencies they provide safe refuge for residents. - Conclusion From an architectural perspective, the damaged buildings are not only repaired but also strengthened and upgraded through the modular system, achieving improved climate adaptability while addressing the diverse needs of the community. Functionally, the system integrates urban sunflower agriculture with residential spaces, promoting economic recovery and agricultural security while providing places for healing, collaboration, and social exchange within the community. In an uncertain era, it helps create a collective environment with greater agency, resilience, and cohesion. Under sunlight, the golden sunflowers shine brightly, forming a "sunlit ribbon" that weaves through the entire community. This image symbolizes not only the reconstruction of physical space but also the restoration of individual emotions and shared cultural memory. The competition therefore represents not only a reflection on how to build better architecture, but also an exploration of how to collectively shape a resilient community—one that continues to bloom toward the sun.

Project Information Project Name: Kharkiv Housing Challenge Project Location: Kharkiv, Ukraine Organizer: Kharkiv City Council; United Nations Economic Commission for Europe (UNECE); Norman Foster Foundation; Arup; KharkivProject Institute Competition Organizer: Buildner Design Firm: PILLS Principal Architect: Zigeng Wang Technical Advisor: Yu Yan Design Team: Canqi Mu, Yu Lei, Yurong Jin, Yi Xu Jinyu Wei Consultants: Leilei Gao, Tao Han, Yinxuan Zhang Visualizations: SAN