Hiroshi Nakamura & Nap

Birds's Nest Atami

Birds's Nest Atami
© Koji Fuji / Nacasa & Partners Inc

BIRDS'S NEST ATAMI

Hiroshi Nakamura & NAP

AREA 
10 m²

STRUCTURAL DESIGN
Arup

YEAR
2014

MANUFACTURERS
Hinoki Cypress, Japanese Ash, Japanese Cedar, Plastering Mortar

COLLABORATION
Treehouse Creations

CONTRACTOR
Takashi Kobayashi & Treehouse Creations

COLLABORATION
Treehouse Creations

MAIN STRUCTURE
Steel Three-dimensional Truss

UPPER STRUCTURE
Timber Framework

LOCATION
Japan

FOUNDATION
Diamond Pier

SITE AREA
65,000 M2

CATEGORY
Houses

Text description provided by architect.

I am often struck by the nests that crows build using clothes hangers. Hangers are not only durable but also highly elastic, and they offer more hooks to connect than branches and hence are easier to assemble. Crows, flying deftly across the dichotomy of natural and artificial, are creating a functional and comfortable environment.

Birds's Nest Atami
© Koji Fuji / Nacasa & Partners Inc

When I was thinking about how I would like to make a building like those hanger nests, I received a request from Takashi Kobayashi, a tree house builder.

A tea house of 10m2 or less was desired as the showpiece of “RISONARE Atami,” a new athletic zone built by Hoshino Resorts. The host tree was a great camphor tree over 300 years of age, 6m in girth and 22m tall, enshrined in a lush, virgin forest overlooking the ocean.

The site, however, was a steep slope inaccessible to heavy machineries, and the house itself would have to be established among complexly intertwined branches 10m above ground. Therefore, to enable construction by manpower using light structural members, we chose a composition employing square and hexagonal solid steel rods, 3cm in diameter.

Birds's Nest Atami
© Koji Fuji / Nacasa & Partners Inc

Assembling the rods by connecting the surfaces, we constructed a truss held at two points by strong hexagonal bolts.

For the foundation, we carefully inserted pier type foundations between the roots in order to avoid the use of concrete and large-scale excavation. Using the structure itself as scaffolding, we assembled it by avoiding the branches as birds create their nest, adding or taking out components based on structural analysis.

Birds's Nest Atami
© Koji Fuji / Nacasa & Partners Inc

We mortared the room interior to be like a swallow’s nest. The design leaves open the possibility for visitors to experience nest building by picking up branches from the mountain side and fitting them into walls inside.

The exterior appearance and interior space have a gentle and comfortable atmosphere reflecting the bodily scale of the builders.

Birds's Nest Atami
© Koji Fuji / Nacasa & Partners Inc

It is architecture assembled by intertwining components small enough to carry. The architecture can adapt flexibly to the tree form (as opposed to “site form”) and melts into the forest crowded with dark branches.


Birds's Nest Atami
Plan
Birds's Nest Atami
Structure Joint
Birds's Nest Atami
Section

Hiroshi Nakamura & Nap
T +81 3 64477702 F +81 3 64477798
Hiroshi Nakamura & Nap
108-0072 5-6-18 Shirokane, Minato-Ku, Tokyo, Japan