Introduction The daily life of inhabitants of Hagonoy, the Philippines, is affected by tidal and fluvial floods. Ground subsidence is the main cause of a worsening trend of these floods. Excessive uncontrolled groundwater subtraction creates a ground level decrease up to 5 cm per year. In combination with yearly six to nine typhoons raging over the country, this leads to unliveable conditions. In order to contribute to the improvement of living conditions of the inhabitants, a modular amphibious structure is designed to keep buildings above the water level. Part I -Background In order to design a suitable amphibious foundation for Hagonoy, a research is done into modular, circular building concepts. Hereby a desired translation of the Dutch building concept of Finch Buildings into a Filipino concept can be made. In combination with criteria concluded from research into floating behaviour of structures and from an analysis of the location, a number of criteria is listed, on which the design of the floating modules and the connections is based. Part II – Structural design By analysing and rating several floating construction types and connection types, a concept design for a modular prefabricated amphibious foundation is made. Timber frame, filled with recycled 200L barrels is the basis for a flexible building concept. Three scenarios in which the foundation must give a proper structural performance, are outlined. Due to change in water depth, the structure must be able to function in a dry, a just-floating and a floating position. Since this foundation must be able to carry varying configurations of buildings, multiple load cases can occur. The most unfavourable load cases occur during typhoons, due to high wind pressure and high and long wind generated waves. By creating a parametric visualization and calculation model, a first insight in dimensions, and width and length of the amphibious foundation is determined. This concept design for both foundation modules and connections between modules is elaborated more in detail. A timber structure of 1,20m x 2,40m holds eight 200L barrels in place. Due to brackish water, the timber structural elements must be protected against shipworm attack. In a brief research several possible solutions are described, of which wrapping structural elements with coir is determined to function best, according to previously stated criteria. In this design, barrels can be replaced in case of damages. Prefabricated foundation modules can be connected by a combination of a U-shaped bottom connection, and a relative fast fixable upper connection. By this connection a rigid wide body can be built in order to provide stability for all scenarios. Two case-studies, one being a foundation with a single building and the second being a foundation with a configuration of eight buildings, are tested by means of SCIA Engineer. For the foundation with a single building in floating position, deflections are too high due to extreme wind-generated wave loads. By increasing the width and length, deflections decreases. The largest bending moments and shear forces occur when the foundation with a configuration of eight buildings touches the soil on one side, due to a large heeling moment. These occurring bending moments and shear forces form an input for optimization of both the foundation module and the connection. In order to reduce the demand for groundwater, and thereby to contribute to reduce of ground subsidence, a design is made for making use of rainwater, and store it in the foundation. In addition waste water can be cleaned by integrated helophyte filters. Bamboo mooring piles create horizontal stability. By replanting bamboo, poles can be replaced over years. Part III - Conclusions A design for a prefabricated modular amphibious structure that is applicable in and adjusted to a flood and typhoon prone area, such as Hagonoy is delivered. Concluded from theory of floating behaviour and a rough cost estimation, a foundation for a single building is not recommended. In order to start building the pilot version, knowledge of actual behaviour of wind generated waves, optimization in the field of structural behaviour and costs are recommended.