Solar Still Pavilion for bespoke global event

One of the goals of the SDGs is the simple yet significant challenge of "providing safe water and toilets around the world.” Life was born, civilization developed, and the present society exists in an ecosystem that cannot survive without water. It is an undeniable reality that the present society is neglecting the very source of life, even though it is a part of the ecosystem as one of its organisms. Water is an opportunity to rethink the world and how we relate to this larger ecosystem. Water is also at times a frightening presence. More recently, we have come to realize that water is a scarce resource. We propose a pavilion about “water” as its main theme.

Building, Layout, and Circulation
The roof composed of a circular membrane structure covers the entire site situated next to the main street. Under this roof, there is an inverted concave acrylic water vessel. By pumping into this vessel the seawater from adjacent bay with impurities removed, water evaporated by the heat of the hot midsummer sun condenses on the roof membrane. The condensation droplets form along the roof as filtered water and trickles down from the circular edge. This is a low-tech system that uses the principle of solar-still water purification to produce fresh water even in the absence of electricity. A pool forms on the ground, acting also as a water table, where the dripping water accumulates. Rainwater also accumulates in this pool. The various spaces that are distributed to support this acrylic water vessel and membrane become public spaces that can be approached from any direction, with no front or back. A circulation scheme was designed to allow access to the various programs, such as the information centers, indoor rest areas, and a security station, which are located along the main street side to increase visibility. The restrooms and first aid station are located in a quiet area set back from the main street, with access from the service road taken into consideration. The security center is distributed on two levels with a system that is fully linked to the police boxes. Each of them can be approached by a separate circulation path from the different spaces. The center, which can be reached through the indoor rest area, is a raised ground with a shape similar to the roof and acrylic, and will be considered as a central space for gathering as well as linked to rest areas. It will be a magical space where light and water interweave, where visitors can watch the shimmering of water in the vessel and salt crystals forming at the bottom during the evaporation process. This indoor resting area will also have a second floor, and will be planned as a special scenic place, different from the main street and the first floor, where the water and salt crystals in the water vessel are highly reflective. The drinking area is a place where drops of water from the membrane are collected and served as drinking water. One can experience the cyclic activity of water by purely experiencing fresh water made from seawater.

Structures
Various structural compartments are planned to be made of steel for its lightweight and resilient qualities. Acrylic glass, which is used in aquariums, has a lighter specific gravity than glass and is stronger. The volume of the various spaces and the water vessel rely on each other in the structural orchestration to achieve an uncanny equilibrium. NLT is used for the flooring material on some of the second floors to reduce costs and CO2 emissions while maintaining strength, and ETFE membrane is used as a roofing material for its versatility, light weight, durability, and easy maintenance, as well as its prevalent use in tents, walls, and desalination technology.

HVAC
The plan is to save energy by placing equipments in the upper space of the facility rooms and selecting high-efficiency equipments. The water collected in the water vessel is used for cooling and miscellaneous water in various rooms to conserve water. Water in the vessel will be circulated to ensure sanitation. 

Environmental Considerations
We will hybridize passive environment strategy using natural energy without relying solely on mechanical equipments. We can achieve a comfortable space where the water in the vessel is evaporated by solar heat, the filtered water accumulates in a membrane, and falls onto the water table as a water curtain, further lowering the temperature of the ground surface through evaporation heat. Inside the wall, the wall surface can be cooled by water running through pipes and also circulating pool water. The hydrophilic space is not only refreshing and cool to look at, but also relaxing to experience firsthand. During the event that spans from Spring to Autumn, a comfortable space to rest against the intense Summer heat will be provided, while at the same time reducing the burden on the equipment and reducing energy consumption. Performance can be achieved without spending more energy than necessary.

Disaster Prevention and Security
In the event of a disaster, the area under the large roof can serve as a gathering space to shelter from the rain or heat. Water on site can be used for a wide variety of purposes, including emergency drinking water and firefighting. The dispersed layout of the various rooms allows for flexibility in location and provides a shelter that does not become a congested space.

Recycling/Reuse
Recycled decking materials are used as flooring materials. Steel frame materials for structures will be made from commonly available components for versatility. Salt, which accumulates by evaporating seawater in the large vessel, can be refined and sold during or after the event, or visitors can try their hand at salt making. Historically, Osaka has flourished as a center of commodity distribution since the days when it was known as the "kitchen of the nation," and a variety of goods were traded across the sea.

Once again, we can learn about the sea, salt, and yes, water, and how they have historical values that connected Osaka with the rest of the world.