ECOTONE HOTEL

Project Details

Project Description

The Ecotone Hotel is located on the shores of Biwa Lake, the largest lake in Japan. The project intention is to revitalize the Ecotone (a transitional zone between water and land ecosystems) which had been severely damaged by structures that modifi ed the regional ecosystem, and secondly, to engage the community, strengthening the relationship between residents and nature. As a result, the project proposes a respectful architecture concerned about both society and the environment.

The Biwa Lakeshore, is a delicate transition from an inland water to a forest ecosystem, including wetlands and grasslands. This transitional area has been greatly altered during the 20th century, specific ally during Japan’s period of rapid economic growth. Water pollution caused by the development of buildings and massive infrastructure has reshaped the lakeshore, severing the delicate transition between ecosystems, impoverishing the autochthonous natural wealth. Since ancient times, inner lakes have connected Biwa Lake with the city; creating contact points between people and nature -however, currently, only 23 remain.

Nowadays, humanity is realizing that the price of pursuing short-term interests is high, and quickly becoming clearer. People around the world are questioning their lifestyles and a slow rebirth of this human consciousness towards the environment is emerging.
This project is not only about enhancing Biwa Lake’s surroundings, but a continuous improvement of the natural existing conditions; from the surrounding forests, rivers flowing into Biwa Lake and eventual streams flowing into the ocean. It is of great importance that people be conscious of both the connection between all living things and the thread that connects past and future.

Ecotone
The ecotone is a habitat for various organisms that play a role in removing harmful substances in the environment, suppressing waves, and preventing erosion. The challenge of this project consisted of reviving the ecotone while at the same time not altering the environment with the building; as a result, during the planning phase, the initial approach was set to reproduce the former ecotone that had been destroyed, by making the building a part of it. Green-roofs were conceived as platforms that allow the surrounding natural vegetation to continue living. In the interest of creating a specific biotope for the proposed location, two small ponds were placed on the west side; and a cultivation area was set on the east side- open to active participation from local residents.

Use of light, wind, water, heat, earth, and plants:
Light, wind, water, heat, earth, and plants were considered when designing the building in a relationship with the lake. The wind flows from the lake into the rooms - creating a winding path along the main corridor on the east side. The light reflects from the lake’s surface into the rooms. Rainwater is collected from the roof and distributed into the ponds on the western side. This collected water evaporates and creates a cooling breeze that enters the building. During winter, heat is stored in the earth walls, warming up the rooms at night, additionally, the soil also works as a humidity control mechanism.

Use of regional materials and construction methods
The building uses regional architecture techniques and materials to minimize energy expenditure. The use of soil construction proved to be superior to standard techniques in terms of environmental performance and ecological footprint. By means of computer simulations, and on-site measurements, it was demonstrated that rooms with fully-opened windows -when outside air temperatures range between 18-28 ºC- rendered air conditioning unnecessary. Compared to standard rooms with all openings closed, the combined effect of the structure and earth walls reduces cooling loads by 70%.


Structure
Wind from Lake Biwa flows through the building traveling from north to south, this is achieved by changing the angle of the wall extending from east to west. Reinforced concrete slabs, like folded plates, supported by oblique pillars aim to create a space where structural beams are invisible; the slab’s unique shape can only be perceived from the spaces below where the concrete is exposed. The slab shape also plays the role of eaves, controlling solar radiation. The uppermost slab works as a green-roof where the surrounding natural vegetation continues growing.