The study aims to present, compare, and assess three different types of buildings considered as flood-resilient construction: building on piles (also called static elevation), amphibious building (also called can-float), and floating building in terms of their performance in the context of a semiwild river in a large city. The comparative multiple-case study covers three objects realized between 2014 and 2017 at the Vistula riverbanks in Warsaw, Poland: pile founded Beach Pavilion, amphibious Boulevard Pavilion, and floating Water Tram Terminal. The research was based on the blueprints analysis as well as on on-site observations in the phase of construction and operation and interviews. The general characteristic of the three resilient typologies has been confirmed in the study. The pile building has an almost unlimited range of operation regarding the water level on the cost of a relatively remote location from the river, but during an exceptionally extreme flood, it will be flooded. Floating buildings provide the best visual and physical contact with water, cannot be flooded, and may be relocated but access to them from land is hampered, especially during very low and very high water levels. Amphibious buildings seem to be a compromise of water proximity and reliability of operation in all circumstances. A closer look reveals technical problems with buoyant structures. In the case of the floating terminals, problems with mooring on the semiwild freezing river remain a challenge. The amphibious buildings are still in the phase of implementation, waiting for their first test in natural flooding conditions.

Dynamic development in practically all fields of science and engineering has not passed over shipbuilding. In last years, engineers got to their use computer software which makes it possible to perform strength and hydrodynamic calculations as well as to visualize design projects in 3 D space [1-4]. At their disposal they have full spectrum of modern solutions associated with the use of advanced materials and technologies [5-7]. More and more attention is also paid to impact onto the natural environment [8,9]. Every new object must influence the environment as low as possible, beginning from building phase through its service life up to final utilization - such approach is called „green-shipping“. However, not only practical reasons are important. Clients, i.e. ship owners and passengers of ships paid more and more attention to image of floating units. During decision taking on that from whom a transport service has to be ordered, the most modern ships of an attractive image matching with place and time, are often taken into consideration. Such situation has become a basis for an idea of working out a concept of a new ferryboat for National Maritime Museum. As the ferry has to navigate in „the heart of the town“, then, apart from strictly marine and engineering aspects, an important factor of its designing is its expected image - a set of significant meanings and emotions written in architecture language. The new ferryboat, like its historical predecessors, will never leave urban water routes.

Since the beginning of the 21st century floating buildings have been growing in popularity in Poland. According to market research and quantitative studies, the majority of operative Polish floating buildings serve for commercial purposes, such as short-term rentals, vacation houses and floating marinas. Simultaneously, despite the increasing demand, the development of floating buildings in Poland is limited by the inconsistent legislation, government policy and, most importantly, natural conditions of Polish inland waters. The most attractive sites for floating architecture are the semi-natural lakeshores and riverbanks. At the same time, low water levels and poor maintenance of many Polish basins require special architectural and engineering solutions. The article presents our experience with meeting the market’s demand for small cost-effective floating commercial buildings despite the local shortcomings of inland waters on the example of the floating apartment built in 2019 on the Roś Lake in Pisz, Poland. The presented building was intended as a water-based extension of the existing hotel on land. It was designed as a “modern barn” with all-glazed gable wall allowing for a spectacular view to the lake. With a 50 sqm footprint, the one-story house with a mezzanine has a small draft of 33 cm and meets the stability criteria defined for inland waters. The presented case study shows that integrating the naval architecture theory, Building Information Modeling simulation along with cutting-edge construction techniques such as Scottsdale Construction System (SCS) and polyurethane spray insulation, can bring significant progress into the development of the floating buildings market in Poland.

Usually, the concept of sufficient stability of a floating structure is connected with the capacity to keep a small heel angle despite the moment of heeling. The variable responsible for these characteristics is the initial metacentric height, which is the relation between the hydrostatic features of the pontoon and the mass properties of the entire object. This article answers the questions of how heavy the floating system should be, what the minimum acceptable draft is, and whether it is beneficial to use internal fixed ballast. To cover various technologies, a theoretical model of a cuboid float with average density representing different construction materials was analysed. The results indicate that the common practice of using heavy and deep floating systems is not always reasonable. In the case of floating buildings, which, unlike ships, can be exploited only under small heel angles, the shape and width of the submerged part of the object may influence the stability more than the weight or draft.

The aim of this study was to assess the feasibility of creating a prototype of a self-sufficient houseboat that is capable of prolonged independence from power grids and freshwater sources. In this design, electricity demand is met by a photovoltaic installation, and the energy is stored in batteries. Fresh water for living needs may be obtained from many sources, depending on the environmental conditions, such as through purifying outboard water, desalinating seawater, and collecting and storing rainwater. No waste production of the vessel can be achieved in two ways: waste can be treated and discharged into a body of water, or processed into fertiliser for later use in agriculture. Four possible locations were analysed: Rome, Lisbon, Gdańsk and Stockholm. The findings reveal that the length of time for which the unit is autonomous and emission-free depends on the geographical location of the facility. In periods when there is overproduction of energy, the system can produce hydrogen, donate energy to the grid, use it for the needs of its own movement, or perform other useful work, e.g. cleaning or aerating the water body on which it is floating.