In consideration of regional issues such as climate condition, heavy snow and seismic possibility etc, the new type of structure called “Sandwich RC Shell” was proposed to realise the integration of the unique architectural form and high structural, environmental, and lighting performance. Arup Japan was responsible for the structural, environmental, fire engineering and site supervision.

Project Name: HOTO FUDO
Architect Name: Takeshi Hosaka architects

HOTO FUDO By Takeshi Hosaka architects - Sheet2The sandwich skin consists of the main RC structure of 100mm thickness, sandwiched 60mm hard urethane for heat insulation and outer 15mm GRC (Glass fibre Reinforced Concrete) to prevent cracking and give high durability. This skin improved enhanced environmental performance, structural strength with light-weight shell and then a long-lived shell structure has been achieved.

HOTO FUDO By Takeshi Hosaka architects - Sheet4This contributes 734 m² spaces with maximum 7.5m height RC shell structure with 1 above-ground floor, has realized by highly CAD and CAE between architect, contractor and ARUP. The shape is developed  by applying the Form-finding analysis in order to reduce strain energy which is similar to Gaudi’s upside down forming. To minimise the complex formwork associated with the shell structure, the solution adopted was a  “Truss Wall System (Pre-fabricated form work)” and approximately 200 units of 3D formed rebar truss were transported from a factory to site. This construction method made possible high accuracy of site work, short construction period and the reduction of complex formwork on site as much as possible.

HOTO FUDO By Takeshi Hosaka architects - Sheet5The environmental design concept was developed to control the thermal comfort for the restaurant building minimizing the energy consumption. The items listed below have been taken into account to make the restaurant space comfortable through the year;

  • “thermal mass” to stabilize the internal surface temperature
  • minimal openings to protect form the summer direct solar radiation and to introduce required daylight into the indoor space
  • outer layer insulation with optimised thickness
  • adopt a sphere shape to maximise volume and minimise external surface area
  • white painted external surface to reflect the direct solar radiation

Takeshi Hosaka architects

Kannai Capital Bid.#503, 2-25, Benten-st. , Naka-ku , Yokohama city , Kanagawa ,2310007 , JAPAN
Tel +81 45 651 2540   Fax +81 45 663 4407

Born in Japan

1999 Bachelor Degree of Architecture from Yokohama National  UniversityEstablished Architecture Speed Studio/ Principal

Master Degree of Architecture from Yokohama National  University−2004   Speed Studio / Principal

~ Established Takeshi Hosaka Architects/ Principal

,April ~ 3, may ,2013 Exhibition “Ku u so u” at Czech Ceske Budejovice House of  Art Museum in Czech Republic

~10, April 2013 Lecturer and work shop at Faculty of Art and ArchitectureTechnical University Liberec in Czech Republic
2015~  Associate Professor at Waseda University


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