The proposed structure is situated beneath the deck of the Lisbon bridge Ponte 25 de Abril, connecting two banks across the Tejo River. The location results from an analysis of the opportunities and threats of the construction site, where favorable conditions regarding services and transportation encourage the expansion of residential areas. However, due to the complex and dense network of infrastructure and built-up areas, it is not possible to further develop this area parcel-wise. Therefore, the opportunity arises to use the existing footprint under the bridge.

The primary intention of the construction is to provide housing in the city center. Economic conditions call for the care of accommodation for young people and the workforce. Therefore, the aim, besides the housing function, is to fulfill the idea of a self-sufficient city suspended under the bridge. The goal is to create housing for communities that can suffice with the functions and uses of the areas that are part of the design, thus becoming their own community and city district. Functions such as culture, sports, market, playgrounds, community gardens, and parks should fully meet basic human needs and could contribute to self-sufficiency from the surrounding city functions. The location itself perfectly utilizes the existing services in the vicinity, eliminating the need to replace deficiencies and instead complementing and elevating the locality to a different level of living.

The placement in the terrain was not a design topic, as the entire structure, except for the entrance core, is suspended from the bridge deck. The solution of suspension was chosen due to the free floor plan, connection to the structure, and utilization of significant floor areas even above the river. The urban aspect relied more on ensuring adequate integration into the surroundings. The bridge itself is an enormous steel structure, exposing its framework, materials, and static solution. Thus, the idea emerged to integrate literally under the wings of the existing construction, leveraging its qualities and characteristics.

Furthermore, the purpose was to utilize any possibilities from the construction site for renewability and self-sufficiency in terms of energy and ecological footprint. The design reflects efforts to install photovoltaic panels, as well as consideration and planning of utility systems. Additionally, wastewater treatment plants, water-to-air heat pumps, waste and rainwater management systems, etc., were included. This way, the building would perfectly blend into the surroundings as an independent entity, enhancing the city center and improving the quality of housing near the historical core.

The residential units are designed to be simple and functional, with each unit offering views of the eastern side of the Tejo River. The interiors feature light and cheerful colors, with the entrance hall finished in warm wooden materials. The bathroom is decorated with Portuguese mosaic patterns in shades of yellow. The living room and kitchen are finished in darker tones to balance the strong sunlight from the eastern exposure with the interior colors. An external steel staircase leads to the living spaces on the second floor, which maintain the same design style. This allows for customization of the interior according to individual preferences. The basic palette of colors and materials not only offers flexible use but also creates a dignified and representative, minimalist space.

The exterior areas serve various functions depending on the level and zone of the floor. Social areas are designed for residents and visitors to meet and relax, with spaces available for baristas and small vendors. These areas are not strictly laid out, allowing for flexible arrangement of furniture. Market areas provide supplies and small livelihoods for residents. Sports areas are designated for recreation and leisure, and playgrounds cater to children's entertainment. The design also includes technical facilities such as photovoltaic panels, water treatment plants, and public toilets. Additionally, park areas serve as visual relief from the heavy and brutalist structures of the bridge.

These functional areas are alternated across different height platforms to provide visitors with the most comfort and a variety of experiences. Street elevators and staircases interconnect these platforms, forming a cohesive and self-sufficient community under the bridge. The goal is not to isolate residents but to enrich their lives, making them a unique and independent urban community within Lisbon.

The construction and material solution is based on the existing structures of the bridge itself. The aim is to achieve maximum integration of the new construction with the existing structure, creating the impression that the building has long been part of the rich panorama. The basis for the design is the steel structure of the suspension bridge, to which the new construction is connected using a group of tension rods. The suspended platforms are made of special steel beams and grids, achieving the required strengths while minimizing the load. Steel structures are complemented by additional metal cladding, and poured floors and surfaces lighten the heavy and cold metallic materials.

Additional materials include acoustic panels, terrazzo tiles, concrete, and rubber surfaces for sports zones. The living units are of a skeletal system, with special modular cladding made of safety tempered and clear glass. Interiors are designed in pastel colors. The intention was to create a rough base for housing that could be easily modified according to the character and habits of individual residents. Therefore, simple wooden and ceramic surfaces with understated painting and simple motifs are used. The use of glass, ceramics, and terrazzo is also in line with traditional materials for Lisbon. An important point was to choose materials that are sustainable, durable, and easily recyclable in the event of aging. Renewability and recycling were integral to the design development.