CWM office / 株式会社CWM総合経営研究所東松山支社新社屋計画

Project Date
用途：事務所
建築：UENOA architects
構造：村田龍馬設計所
設備：EOSplus
施工：伊田テクノス
敷地面積：324.20m²
延床面積：327.18m²
階数：地上2階
構造：木造（CLTパネル工法＋木造軸組工法）
竣工：2026年5月末
写真：UENOAarchitects

【閉じない線を引く】
埼玉県東松山市に建つ税理士・会計事務所「株式会社CWM総合経営研究所」の支社建替計画である。「SYNEGIC office」「YUKI office」に続く、私たちにとって3つ目のCLTオフィスとなる。

旧社屋では執務室が1、2階に分かれ、社員同士の関係が階ごとに分断されていた。一体感を持って働ける平屋が望まれたが、アプローチと駐車場を確保すると平屋は成立しない。そこで総二階建てとし、13.5m角の正方形平面の中に7.2m角の吹抜けを設けた。建物の幅の半分を超える思い切った大きさだが、この余白こそが働く人々をひとつの場に束ねると考えた。

周辺環境に対して開きたい。同時にオフィスとしてのセキュリティのために閉じることも必要である。前作に続き、その両立を「閉じない線」で試みた。開くことは、閉じる振る舞いを考えることから始まる。——それが私たちの一貫した姿勢である。

スタディの転機は、外形と吹抜けをともに正方形とし、2つの正方形をL型壁によって浮かび上がらせる構成に至ったことである。恣意的に置かれていた壁が、正方形の秩序をつくる要素へと転じた瞬間、壁は機能から解放され純粋で力強いものになった。正方形の秩序を保ちながら、中心の吹抜けに対してどの程度開くかを壁の長さなどで調整し、L型壁を5つにすることとした。

壁はヒノキCLTを弱軸方向に用い、2層分6.5mの「通し壁」として吹抜けを貫いて立ち上げた。L型壁の構成は壁を複層させ木の圧倒的な量塊感を生み出す。構造材や環境配慮の文脈で語られがちなCLTだが、私たちは木の量塊感がもたらす空間の豪華さにこそ可能性を見続けている。

屋根架構は、X字に組んだリボン梁を吹抜けを囲む4辺に卍型に配し、L型壁による平面構成に呼応させた。梁の形状を活かして天井を2段とし、その間に東西南北のハイサイドライトを設けている。光は時間とともに梁に陰影を描き出す。外装はL型壁ごとにガルバリウム鋼板をエンジとシルバーに貼り分け、内部の構成をファサードに表した。

閉じることを考え抜くことで、初めて開くことができる。閉じない線が、賑わいと静けさの共存する執務の場をつくり出すことを期待している。

Project Data
Use: Office
Architecture: UENOA architects
Structure: Ryoma Murata Structural Design Office
Building Services: EOSplus
Construction: Ida Techno's
Site area: 324.20 m²
Total floor area: 327.18 m²
Floors: 2 stories above ground
Structure: Timber (CLT panel construction + conventional wood framing)
Completion: End of May 2026
Photography: UENOA architects

【Drawing Unclosed Lines】
CWM office is the rebuilding of a branch office for CWM, a firm of tax accountants and accountants, in Higashimatsuyama, Saitama. Following SYNEGIC office and YUKI office, it is our third CLT office.

In the old building, the offices were split between the first and second floors, and staff relationships were divided floor by floor. The client hoped for a single-storey building where everyone could work with a sense of unity, but once the approach and parking were secured, a single storey was no longer possible. We therefore built two full storeys and placed a 7.2 m square atrium within a 13.5 m square plan. Spanning more than half the width of the building, it is a bold size, but we believed this void would be what brings the people working here together in one place.

We wanted the building to open to its surroundings, while also closing it to provide the security an office needs. As in our previous project, we sought to achieve both through "unclosed lines." Opening begins with thinking about how to close. That has been our consistent stance.

The turning point in the study came when we made both the outer form and the atrium square, with L-shaped walls bringing the two squares into view. The walls, which until then had been placed arbitrarily, became elements that create the order of the square, and in that moment they were freed from function and became pure and powerful. While keeping this order, we adjusted how far the building opens toward the central atrium through the length of each wall, and settled on five L-shaped walls.

The walls are hinoki (Japanese cypress) CLT used along its weak axis, rising 6.5 m through two storeys as "through-walls" that pierce the atrium. The L-shaped arrangement layers the walls one behind another, creating an overwhelming sense of the mass of timber. CLT is often discussed as a structural material or in terms of environmental performance, but we continue to see its potential in the richness of space that the mass of timber brings.

The roof structure consists of X-shaped "ribbon beams" arranged in a pinwheel pattern on the four sides of the atrium, responding to the plan of L-shaped walls. Following the shape of the beams, the ceiling steps in two levels, with high-side windows facing north, south, east and west between them. Over the course of the day, the light traces shifting shadows across the beams. On the exterior, each L-shaped wall is clad in galvalume steel in either deep red or silver, expressing the interior composition on the facade.

Only by thinking through how to close can a building truly open. We hope these unclosed lines will create a workplace where liveliness and quiet coexist.