Amidst the periphery of a hairpin curve carved out from a mountain rises the elegantly designed House Momoyama. The Japanese word ‘Momoyama’ translates to Peach (Momo) Mountain (Yama). The two-bases residence designed as a weekend home resides in the Atami city of Japan. The design of the house with its prominent irregular roof, incorporated with the garden trees, and the exterior walls define the interior space.
Furthermore, the architect behind this creation, Erika Nakagawa, desired to express the idea that House Momoyama is an amalgamation of its interior, surrounding environment, and distant mountain view.
House Momoyama is located right next to a rising hairpin road and has been inhabited for some time. Due to the difference in road levels from one point to another, retaining walls of different heights were built across the outer perimeter of the house. The land’s previous owner had left behind a few dozen boulders of rocks and a handful of vibrant garden trees. Erika Nakagawa and her team wanted to create a unique space of architecture that blends with the site’s existing conditions and enhances the feel of the site environment for the clients.
Planning of Space
One of the symbolic characteristics of the site is its mountain scenery. Along with this, the current features of the place gave it a unique appearance. It was keeping these both in mind, Ar. Erika fashioned a prominent irregular-shaped roof that captures the scenic view and, at the same time, doesn’t disturb the surroundings within the site.
In the initial stages, the column layout planned for House Momoyama created a feeling of constriction. Afterwards, a few of the columns that supported the roof shifted to a location outside the structure, and the interior became better connected with the site. This approach helped to define a new boundary between inside and out.
As a routine, a design begins to take shape when we start taking 3D sections from a flat plain and then work on the required framework. But here, the architect first decided to understand the terrain from which the sections were derived. Later on, the framework of the house was determined by the team, and they implemented top-grade materials that have a prolonged lifespan for its construction. After a trial of filling in the residential space with household items, the plan started to take shape.
Currently, House Momoyama utilizes thirty-eight per cent of the site area (458.17 sq.m) for its interiors, and the surplus portion gets beautifully landscaped, adopting the existing site features.
The Model Philosophy
To better understand how to advance further into the project, architect Erika began to create models of House Momoyama. Starting with a model in 1:50 scale, Erika was able to establish a connection with the outer walls and roof structure up to some extent. Then, a model of the 1:20 scale was prepared, which helped to understand the interior spaces and their division and dived deeper into the design process. Before the construction commenced, a 1:1 scale model of structural joints were made to make the final required changes.
A Perfect Blend of Materials
Architect Erika and her team categorized the materials used for House Momoyama into four parts during the entire design and construction process. The first one being “Existing Materials,” referred to the plants and retaining walls pre-existing on-site. “Materials necessary for daily life” are the new furniture and miscellaneous walls while the “Boundary materials” were for the flooring, glass walls, the roof structure and its supports.
Finally, the “Environmental Materials” pertains to its surroundings. Equal importance was given to the visual and texture feel of materials so that the boundaries between the existing and new materials become tallied.
A terracotta floor extends into the garden that provides an area for the dining space and separates the living and dining room boundary line. Light plywood walls cover the master bedroom and workplace for privacy. A tatami-mat tea room is located to the back of the site, where parts of its interior walls and ceilings are covered with light plywood, and the remaining positions are filled with concrete.
Furthermore, the architect wanted the house to be unified with its neighbourhood. Hence, the materials bought into the site were carefully chosen and made sure that they blended with the site’s existing features.
Construction of House Momoyama
The main structural components of the house are its irregular-shaped roof and the pillars that support it. Several constraints followed while designing the top, the biggest one being the site location. Due to the sea nearby the site location, the roof couldn’t be weld into a single component, and because of the difference in road level, the roof structure can’t be made from a single raw material. Hence, assembling the roof from smaller components and tightening them together using bolts was implemented.
Arranging the concrete pillars for the roof support was done in accordance with the open plan concept of the house. A few of the supports were kept outside the roof structure and connected to the structural frame via extended steel beams to achieve the idea leading to House Momoyama. The columns were also fixed at the intersection of the grid and arranged at a certain distance to overcome the cramped feeling. Glass and steel structure makes the house’s outer walls and gives the seamless connection between the interior and outside environment.
Path to Sustainability
In Japan, there are mainly three public systems governing sustainable housing design, namely, the Housing Performance Indication System (HPIS), Long-life Quality Housing (LQH) certification, and Comprehensive Assessment System for Built Environment Efficiency (CASBEE). The HPIS assesses the housing performance, LQH certifies the houses which meet the criteria of long-life quality housing, and CASBEE assesses and rates the sustainability of detached houses. House Momoyama is constructed using eco-friendly and long-lasting materials such as reinforced concrete, glass, steel, plywood, terracotta, etc. It also exceeds the minimum area requirement of a house set by the LQH certification.
The combination of glass and steel framework ensures proper ventilation and a good amount of daylight entering throughout the residence. Furthermore, the garden area and exterior area ratio exceeds the minimum set ratio of forty percent. House Momoyama truly conveys the message of dynamic coexistence between the interior and exterior space of a structure. Each decision made to achieve this smooth transition, from the placement of columns to the glass and steel structure, inspires architects to set a higher benchmark.
Jensen, J., 2020. Architects Directory 2020: Erika Nakagawa, Japan. [online] Wallpaper*. Available at: <https://www.wallpaper.com/architecture/architects-directory-2020-erika-nakagawa-japan> [Accessed 14 July 2021].
Abdel, H., n.d. House Momoyama / Erika Nakagawa Office. [online] ArchDaily. Available at: <https://www.archdaily.com/934941/house-momoyama-erika-nakagawa-office> [Accessed 14 July 2021].
Masuda, S. and Nakagawa, E., 2021. Garden-like and exterior-like things ── Thinking from “frame windows”, “first roof”, and “Momoyama House”. [online] 10＋1 website. Available at: <https://www.10plus1.jp/monthly/2017/11/issue-02.php> [Accessed 14 July 2021].
Fujihira, K., 2017. Case Study: Detached House Designed by Following the Control System. [online] intechopen. Available at: <https://www.intechopen.com/books/sustainable-home-design-by-applying-control-science/case-study-detached-house-designed-by-following-the-control-system> [Accessed 14 July 2021].