Optical Glass House in Hiroshima
Surrounded of the tallest buildings in the center of Hiroshima, Japan, emerges almost nanoefeito, a small glass house near a passing cars and trams. And to obtain the highest level of privacy, the architect Hiroshi Nakamura & NAP developed a garden that allows imposing total tranquility to the external environment of the project, using the format of planting to filter some of the light natural tones as the sun mutate over the day.
The facade comprises more than 6000 blocks of pure glass, creating a clean scene, in contrast to raw materials which increase the difficulty of the manufacturing process, elements that enable a freshness ideal for the residence beyond a certain portion optical illusion. All this surrounded by a fountain of steel suspended in contact with a cut out of 50mm steel, which gives the technique a result semi invisible, creating an interesting visual composition.
The glass blocks are strung together by stainless-steel bolts suspended from a beam above. They are also stabilised by stainless-steel flat bars at 10mm intervals. The mass of the supporting beam below is laterally minimalised by employing a pre-tensioned steel beam encased in reinforced concrete. Despite the facade’s massive weight, it appears to be transparent from both the garden and street. Seen from inside, the glass garden brings the entire house to life.
From inside the glass garden, you can begin to fathom the incredible structural gymnastics required to support the 13-ton facade made up of 6,000 glass blocks, each measuring 50mm x 235mm x 50mm. With their large mass-per-unit area, the crystalline glass blocks, effectively shut out the urban noise and create a sparkling backdrop for the garden with modulated city views.
- Fabricated from 6,000 long, thin blocks, the huge glass wall forms a lustrous veil, screening out the distractions of the city and enclosing a verdant courtyard garden at the heart of the house.
- The house in its city context. Hiroshima’s bland and alienating urban texture is based on the needs of the car rather than any sense of human scale or intimacy. From the street, the garden is diffused and refracted through the shimmering glass wall. The glass retains micro-scale surface irregularities that generate and project unexpected visual effects around the interior spaces.
- The 13-ton facade made up of 6,000 glass blocks, each measuring 50mm x 235mm x 50mm. With their large mass-per-unit area, the crystalline glass blocks effectively shut out the urban noise and create a sparkling backdrop for the garden with modulated city views. Their high degree of transparency was achieved by using borosilicate, the material used to make optical glass. The difficult casting process required slow cooling to remove residual internal stress and achieve precise dimensions
- The glass blocks are strung together by stainless-steel bolts suspended from a beam above. They are also stabilised by stainlesssteel flat bars at 10mm intervals. The mass of the supporting beam below is laterally minimalised by employing a pre-tensioned steel beam encased in reinforced concrete.
Hiroshi Nakamura & NAP:
A renovation project of an entrance hall for an office building in Ten-nousu, located on the waterfront of Tokyo .We attempted to represent the beauty of the riverside with the interior flooring; by setting pebbles in hardware resistant clear epoxy resin. By casting the resin using concrete casting technique, we’ve succeeded in overcoming problems such as cracks, unevenness and achieved an excellent clarity of the resin. The finished15mm thick clear resin flooring resembled river surface. It was as if the river from the outside emerged into the entrance hall. Walking on water and sitting on a chair that floats on the river, the lounge became a weightless oasis where your sense of gravity became totally defeated.
This house is sited among tall buildings in downtown Hiroshima, overlooking a street with many passing cars and trams. To obtain privacy and tranquility in these surroundings, we placed a garden and optical glass façade on the street side of the house. The garden is visible from all rooms, and the serene soundless scenery of the passing cars and trams imparts richness to life in the house. Sunlight from the east, refracting through the glass, creates beautiful light patterns. Rain striking the water-basin skylight manifests water patterns on the entrance floor. Filtered light through the garden trees flickers on the living room floor, and a super lightweight curtain of sputter-coated metal dances in the wind. Although located downtown in a city, the house enables residents to enjoy the changing light and city moods, as the day passes, and live in awareness of the changing seasons.
Optical Glass Façade:
A façade of some 6,000 pure-glass blocks (50mm x 235mm x 50mm) was employed. The pure-glass blocks, with their large mass-per-unit area, effectively shut out sound and enable the creation of an open, clearly articulated garden that admits the city scenery. To realize such a façade, glass casting was employed to produce glass of extremely high transparency from borosilicate, the raw material for optical glass. The casting process was exceedingly difficult, for it required both slow cooling to remove residual stress from within the glass, and high dimensional accuracy. Even then, however, the glass retained micro-level surface asperities, but we actively welcomed this effect, for it would produce unexpected optical illusions in the interior space.
So large was the 8.6m x 8.6m façade, it could not stand independently if constructed by laying rows of glass blocks a mere 50mm deep. We therefore punctured the glass blocks with holes and strung them on 75 stainless steel bolts suspended from the beam above the façade. Such a structure would be vulnerable to lateral stress, however, so along with the glass blocks, we also strung on stainless steel flat bars (40mm x 4mm) at 10 centimeter intervals. The flat bar is seated within the 50mm-thick glass block to render it invisible, and thus a uniform 6mm sealing joint between the glass blocks was achieved. The result?—a transparent façade when seen from either the garden or the street. The façade appears like a waterfall flowing downward, scattering light and filling the air with freshness.
The glass block façade weighs around 13 tons. The supporting beam, if constructed of concrete, would therefore be of massive size. Employing steel frame reinforced concrete, we pre-tensioned the steel beam and gave it an upward camber. Then, after giving it the load of the façade, we cast concrete around the beam and, in this way, minimized its size.
- As a result, we achieved a transparent facade like a waterfall can see from both the road side and garden side.
Project name: Optical Glass House
Location: Hiroshima, Japan
- Type By Characteristic: Japanese House, Renovation / Expansion / Extension : House
- Type By Site: City / Town House
- Type By Size: Medium House – (201 sqm – 450 sqm)
- Type By Structural: Glass House
Total floor area: 330 sqm
Completion Year: 2012.10