構  造:鉄筋コンクリート造 + 一部木造小屋組( 改修部分 )
構  造:鉄筋コンクリート造( 増築部分 )
階  数:地上2階
延床面積:1,680㎡( 改修部分:672㎡、増築部分:1,008㎡ )

金箱構造設計( 構造設計 )
アトリエブンク + 総合設備計画( 設備設計 )

築50年以上になる役場庁舎の大規模改修( 耐震・断熱性向上 )と防災センターの増築である。既存庁舎は緑の板金屋根と赤橙のレンガ壁が印象的な外観であり、本計画でも町の条例に基づいた濃緑の勾配屋根を採用することが求められた。既存庁舎のRC躯体及び木造の小屋組を残すことを与条件に、機能性向上や新旧の対峙を読み解きながら計画を進めた。


Kuromatsunai Town Hall Renovation / Disaster Prevention Center

Kuromatsunai-cho, Hokkaido

Structure:RC+W( Renovation part )
Structure:RC( Extension part )
Floor:2 Floors
Floor Area:1,680㎡( Renovation:672㎡、Extension:1008㎡ )

Kanebako Structural Engineers( Structural Design )
Atelier BNK+Sogo Consultants( Mechanical & Electrical Engineering )

This project involved the large-scale repair (earthquake proofing and insulation) of a Government Office Building, which had stood for more than 50 years, and the expansion of the Disaster Prevention Center. The existing Government Office Building has a particularly impressive appearance due to its green sheet metal roof and reddish orange brick walls, and town regulations demanded that this plan adopt a dark green pitched roof. These conditions also demanded that the RC skeleton and wooden roof trusses of the existing building be kept, and we pursued our plans while balancing the need for functional improvement and the problem of the conflict between the old and new.
In terms of function, the Government Office Building and Disaster Prevention Center are united, and our goal was to allow adequate functionality on a daily basis. The area allotted for the enlargement of the Disaster Prevention Center was a single span on the southern side of the building, and the entrance hall in the existing Government Building was secured. By the creation of additional depth, the disordered desk layout was rearranged. The remaining area allotted for enlargement was the Disaster Prevention Center on the northern side of the building, which was planned to be added at the same width as the existing building. This Center functions as a base for anti-disaster measures in an emergency, and provides community facilities for citizens and additional space for the government offices on a regular basis. The central colonnade forms a deep recessed area which is utilized as a staff service zone, and ventilation is generally supplied from the high side by wind.
The exposed concrete internal walls were repaired and painted white only where defective. The contrast formed between the shaded concrete walls and the fresh new white surfaces helps remind us of the time elapsed since the building’s initial construction. The ceiling height of the new extension is also greatly influenced by the existing building, with a variety of expanses created through the union of the old and new.
For the outside of the existing Government Office Building, with its dark green sheet metal roof set on trusses and brick walls, we adopted the same old-new design technique. In addition, we took particular pains with the details so as to avoid revealing the junctions between the old and new portions and enhanced the overall unity of appearance by adding details, such as eaves and continuous windows, of similar design.
We aimed at reproducing the original appearance while leaving existing features.