Case Study - Attached Deck Pt. 2

Two story house with a metal attached rooftop deck in Komaba, Tokyo

The metal deck was attached to the house's rooftop 15 years later than the houses original construction. It was meant to serve as a laundry drying space and it cost 50,000 yen to install (approximately 500 US dollars). The deck structure appears to be a very typical metal structure (similar to those from the Attached Deck typology found around Tokyo). However, it has a small additional second level serving as a threshold from the house's second level onto the slightly sloped eaves of the roof above the entrance, from which a set of stairs leads to the deck itself.

Still, however cramped the rooftop conditions are, the owner of the house is speaking quite fondly of the rooftop space. He sees it as having the feeling of openness—the quality which has been progressively lost over the years due to the urban development around the house.

One of the issues in connection to the rooftop deck that has been mentioned by the owner- is that it becomes troublesome to use in strong wind (which occurs fairly often in Japan, especially at the change of seasons). There is no barrier or protective net/surface on the sides of the structure, so in case of strong winds the drying laundry is in danger of being blown off the deck.

Another concern that the owner has with the structure is its weight. Japan has extremely high seismic activity, where small earthquakes can occur on almost a weekly/monthly basis, and a stronger earthquake is expected in the near future (Mogi, 2004).

Consequently, the house owner is worried about the excessive weight of the metal deck structure in relation to the timber structure of the house, which can cause great damage at the time of a big earthquake. Therefore, among the things that the owner would like to improve about his deck, he is primarily concerned with having a more lightweight structure.

Other blog posts: