アフリカで最も高い木造タワー計画！

©︎ OMT Architects

〈ブルジュ・ザンジバル（BURJ zanzibar）〉は、アフリカ初となるハイブリット木造の建築です。コアは鉄骨鉄筋コンクリート、柱はグルーラム材（木材を重ねて接着してつくられる構造用木材）、スラブはCLTにより構成されています。木造を使用した建築としては、アフリカで最も高い建築となる予定です。また、構造やファサードはモジュール式となっており、高い柔軟性や建設期間の短縮、コスト効率の良い品質を実現します。

構想やコンセプトはニューヨークを拠点とするリアンダー・ムーンズ（Leander Moons）が行い、建築設計と詳細設計はベルリンを拠点とするOMTアーキテクツ（OMT architects）とシュトゥットガルトに拠点を置くビルク・ハイルマイヤー・アンド・フレンツェル・アーキテクツ（Birk Heilmeyer Frenzel Architects）が担当しました。

（以下、OMT architectsから提供されたプレスキットのテキストの抄訳）

〈ブルジュ・ザンジバル〉は、東アフリカに位置するタンザニア、ザンジバルシティ周辺にて開発中の都市フンバ・タウンの中心部に計画されている。

それぞれの住戸と最上階のペントハウスからは、海、都市、島の素晴らしい眺望を楽しむことができ、アメニティスペースと商業スペースを含む建物は、居住者と訪問者に付加価値を提供する。

環境に配慮したサステナブルな設計思想と、バランスのとれた住戸構成やアメニティスペースにより、トレンドと地域文化を融合させた、進化し続ける個性的なタワーとなり、ザンジバル諸島を象徴する建物の1つとなることだろう。

©︎ OMT Architects

さまざまなライフスタイルに対応する柔軟な構成

このタワーは高い柔軟性と適応性を備えた革新的な構成となっている。

小さなスタジオから1ベッドルーム、広大な2ベッドルームのペントハウスまで、すべてのアパートメントは同じモジュールに基づき構成されている。この設計手法により、異なるレイアウトやサイズのアパートメントを、すべてのフロアに柔軟に配置することが可能となっている。またこのコンセプトは柔軟性の向上だけでなく、建設期間の最適化とクオリティの向上にも貢献している。

©︎ OMT Architects

建物の外壁デザインにも、モジュール方式が採用されている。3種類のモジュールにより構成されたファサードは、奥行きと機能の異なるモジュールを交互に配置することで、遊び心のある外観をつくり出すとともに恒久的な日除けとなり、この地域の気候に対応したファサードとなっている。

屋外廊下やバルコニーには植栽を配置することもできるが、パノラマウィンドウを設置することで住戸に組み込むことも可能となっている。この柔軟性により、居住者の文化的背景や家族構成、ライフステージによるそれぞれのライフスタイルに対応するための個別のソリューションを可能にする。これにより用途や職業の多様性を生み出し、〈ブルジュ・ザンジバル〉は「垂直な緑の村」として発展していく。

©︎ OMT Architects

©︎ OMT Architects

表情豊かで遊び心のあるファサードにより、一般的な高層住宅プロジェクトに比べ、室内のプライバシーをより高いレベルで確保することができる。

外壁に使用する白い漆喰は熱の侵入を抑え、ゴールドアルマイトの窓は建物の高級感を高める。ルーフガーデンや植栽のあるバルコニーは、タワーの緑を引き立てるとともに、地域の気候や周辺環境と調和させる。

©︎ OMT Architects

©︎ OMT Architects

環境負荷を低減する「ハイブリッド木造」

タワーの構造は8×8mのグリッドに基づき、住戸とファサードは細分化した4m刻みのグリッドにより構成されている。〈ブルジュ・ザンジバル〉はアフリカ初となるハイブリッド木造の建築であり、コアは鉄骨鉄筋コンクリート、柱はグルーラム材（編集部注：木材を重ねて接着してつくられる構造用木材）、スラブはCLTにより構成されている。

ハイブリッド木造のアプローチは、建物のエコロジカル・フットプリント（編集部注：人間の活動において地球環境に掛けている負荷の大きさを図る指標）を減らすと同時に、内部環境を向上させることができる。

また構造体が軽量化されることにより、基礎部分にかかる荷重を軽減することができ、ほとんどの部材がプレファブリケーションでの製作が可能であり、工程で発生する廃棄物の量も少なく、残った廃棄物のほとんどは効果的にリサイクルすることができる。モジュール式のファサードコンセプトも同様のアプローチとなっており、タワーのシンプルさと費用対効果の高いコンセプトをさらに高めている。

©︎ OMT Architects

©︎ OMT Architects

〈ブルジュ・ザンジバル〉のバックグラウンドとなるフンバ・タウンのさまざまなプロジェクト

OMTアーキテクツは何年も前から、「フンバ・タウン」というまちを、主に木材を使ったさまざまなシステム、さまざまなスケール、さまざまなプロジェクトにより構築している。〈ブルジュ・ザンジバル〉のような野心的なプロジェクトを可能にするためには、これらの既存のプロジェクトが鍵となるのである。

「フンバ・タウン（Fumba Town）」
サステナブルな都市として構想されているフンバ・タウンは、東アフリカで急成長しているザンジバルシティに近接している。またフンバ・タウンには、シリコン・ザンジバル構想の一環として、アフリカ大陸のハイテク企業の誘致が始まっている。

シリコン・ザンジバル構想：ザンジバルにハイテク企業を誘致し、アフリカにおけるテクノロジーのハブとなることを目指す構想

FumbaTown ©︎ OMT Architects

「フンバ・スポーツ・クラブ（Fumba Sports Club）」
地域にさまざまなスポーツの選択肢を提供することを目的とするプロジェクト。テニスコートを中心に設計された施設は、夜間は屋外型の映画館や劇場として活用することもできる。それぞれの施設は、シンプルで地元のものを用い、限られた予算の中で丁寧に設計されている。

Fumba Sports Club ©︎ OMT Architects

「ブスタニ・ヴィラ（Bustani villas）」
フンバ・タウンの中で最も高級なヴィラであり、伝統的な建築様式を用い、海への眺望と居住者のプライバシーを重視した設計となっている。また、エアコンが設置されているが、自然換気と遮光を最大限に活用することで、冷房に必要なエネルギーを最小限に抑えている。ヴィラは3ベッドルームと5ベッドルームの2つのサイズがあり、それぞれのヴィラはクライアントのリクエストに応じた設計となっている。

Bustani villas-3Bed ©︎ OMT Architects

Bustani villas-5Bed ©︎ OMT Architects

「チェイチェイ・リビング（CheiChei Living）」
地元住民を対象とした住宅供給（※）プロジェクトであり、1万ドル前後の手頃な価格のユニットを提供している。チェイチェイ・リビングは、ブスタニ・ヴィラのようなハイエンドな商品と統合することで資金を調達しているため、他の公正住宅（※）プロジェクトよりもはるかに優れた枠組みを持っている。さらに、チェイチェイ・リビングには木材を使用しており、さまざまなエンジニアリングシステムとローカルシステムを組み合わせることで性能を最適化し、プロジェクトのコスト効率を高めている。

公正住宅：英語でEquitable housing。所得格差や人種などのマイノリティグループに健全な住環境を提供するため提唱されている考え方。世界的に住宅市場は排他的であり、人種の違いなどから十分な住環境を得られず、新型コロナの感染率が高まっていることなどから機運が高まっている。

CheiChei Living ©︎ OMT Architects

CheiChei Living ©︎ OMT Architects

Masterplan

以下、OMT architectsのリリース（英文）です。

BURJ ZANZIBAR

ADDRESS | In the heart of Fumba Town, one of the fast-growing urban developments around Zanzibar City, a remarkable new tower is designed. Within this dynamic urban context and directly at the Indian Ocean, the residential tower will be highly visible and stand out through its distinctive architecture.
Representing a young, vibrant and most of all sustainable lifestyle, the building will allocate a mixture of studio, 1- and 2-bedroom apartments. Like all other apartments the penthouses on the top floors of the tower will offer extraordinary views towards ocean, city and island. Throughout the building amenity and commercial spaces offer additional value to residents and visitors alike. The green and sustainable design concept combined with a well-balanced apartment mix and amenity spaces contribute to an ever-evolving character of the tower, combining mundane trends with local culture. ‘BURJ zanzibar’ will become one of the island’s iconic new addresses.

INNOVATIVE | The innovative layout of the tower allows for highly flexible and adaptable apartment solutions. All apartments, reaching from small studios to vast 2-bedroom penthouses, are based on the same modular layout. Through this design approach apartments of different layouts and sizes can be allocated throughout all floors with maximum flexibility. In addition to the increased flexibility this concept will also contribute to an optimized construction time and enhanced finished qualities.
A similar modular approach has been applied to the design of the shell of the building. Utilizing only three types of modules a playful facade has been created by alternating and changing module depth and function. At the same time the facade addresses the local climate by providing permanent sun shading. The enclosed loggias and balconies contribute to the private character of the apartment’s interior. These outdoor spaces can be transformed into planter boxes but could also be included in the apartment by implementing a panorama window. This innovative and flexible architectural concept allows for individual solutions to accommodate the resident’s lifestyle related to their cultural backgrounds, family sizes and different stages of life. The design will create diversity in use and occupation: ‘BURJ zanzibar’ as a vertical green village.

EXPRESSIVE | ‘BURJ zanzibar’ and its remarkable and vivid architecture will become one of Zanzibar City’s new landmarks. The white plaster will help to reduce heat gain, while the gold-anodized windows will contribute to the high finished qualities. The roof gardens and planted balconies will enhance the green nature of the tower while blending in with the local climate and surrounding. Residents can have their own outdoor garden even when living on the 27th floor! The expressive yet playful design of the facade contributes to a greater level of privacy on the interior as most high-rise residential projects. The possibilities to set an individual note by the integration of room extension, planters or even a panorama window truly set ‘BURJ zanzibar’ apart.

SUSTAINABLE | The structural concept of the tower is founded on an optimized grid from eight-by-eight meters and subdivided for the apartment and facade layout into steps of four meters. The core includes all vertical circulation and means of egress for the tower. Risers and shafts are located centrally and run without transfers close to the core of the tower over its complete height. Multiple structural systems could be applied, from conventional concrete up to a hybrid timber system. Build in hybrid-timber ‘BURJ zanzibar’ would be the first in Africa. The hybrid timber approach would reduce the ecological footprint of the building whilst enhancing the climate within the interior. The reduced weight of the structure would also have a positive effect on the foundation. As most components can be prefabricated also the amount of waste produced during the process is limited and most of the remaining waste can be recycled effectively. The modular facade concept follows the same approach and as such adds to the simplicity and cost-effective concept of the tower. At the same time the modular yet playful facade creates permanent sun shading for all apartments minimizing heat gain. Finally, the inclusion of planting not only significantly reduces storm water impact, but also contributes to a pleasant interior climate.

ICONIC | The design of ‘BURJ zanzibar’ directly relates to its young, vibrant and sustainable residents. The elegant tower is placed on a terraced podium allowing for shared and private gardens and outdoor spaces on the lower levels. Green pockets integrated in the façade create the impression of plants growing up towards the rejuvenating top of the tower. The setbacks on the upper most floors enhance the green experience whilst also contributing to the elegant silhouette of the building. The green roof gardens and planted balconies allow for the integration of nature to reflect a sustainable lifestyle and help to reduce the carbon footprint of the building. The alternating facade concept represents the vibrant character of the project and Zanzibar as one of the most beloved destinations in the World. Most importantly this Icon will create flexible and sustainable living qualities to the highest standards for its residents.

APARTMENT TYPOLOGIES

FLEXIBLE | The tower is envisioned as a highly adaptable and flexible vertical village within an optimized effective structural system. The clear and repetitive framework creates the opportunity to integrate multiple different apartments not only in terms of their size – number of bedrooms – but also regarding their orientation and vertical location within the tower.
The studio apartments, starting from 22 square meters living area, offer a generous room with build-in pantry kitchen and bathroom. The studio apartments in the podium of the building are designed to allow an increased living area up to 42 square meters, combined with stunning views. Some of these podium studio apartments come with private gardens.
The 1-bedroom apartments combine the area of two studio apartments and start at 42 square meter living area. The living and dining space is well dimensioned and features an open kitchen layout. The bedroom has access to a private balcony and ensuite bathroom. The corner apartments allow for an increased living area up to 60 square meters combined with amazing views towards the ocean.
The 2-bedroom apartments evolve around a spacious living and dining area with grand kitchen. The central room allows for flexible layouts and the optional panorama windows and room extensions create individual design solutions for each resident. Balconies and planters grant the bedrooms with a private and intimate character even if located on the upper most floors.
The penthouse apartments are located on the top floors of the tower. They offer extraordinary all-around-views over Zanzibar and the Indian Ocean. In addition to the unique views these apartments are designed with an increased living area to enhance the living qualities even further. The apartments located at the setback levels come with a well elevated private garden and optional infinity pool, a unique feature!

CONVENIENT | The entrance to the tower is located at the main entry plaza. Adjacent to the entrance commercial units allow for retail and hospitality functions. An open stair in the double story entrance hall connects directly up to the commercial space on the first floor. These spaces on ground and first floor could offer both public and resident-restricted amenities. On top of the podium structure a vast outdoor garden with terraces and an infinity pool creates a unique outdoor space with a stunning ocean view. On this level also the majority of the amenity spaces for the residents are located. A clear organized central elevator core provides access to all floors of the building.

FACADE CONCEPT

DIVERSE | The three-dimensional character of the facade is created by the implementation of alternating extruded pods on all sides of the tower. These pods describe the spatial divisions on the tower’s interior and at the same time provide permanent sun shading to minimize heat gain for every apartment within the building. A simple setback on every second floor contributes to the lively impression of the facade and the tower.
The design intent of the facade is to provide a framework for every apartment, from studio up to penthouse, to create its own unique character. The individual ability to configure and use the exterior space as an extension of the interior living space is a key feature in the facade concept. Several options have been created to be included into the design as per the clients and/or residents requests. These reach from the extension of the living area combined with the integration of a panorama window, to the integration of a planter onto the balcony or an opaque window element. At the same time these created opportunities for individual configurations do lead to a greater diversity of the appearance of the building. Green pockets, panorama windows, balconies and even roof-pools contribute to the iconic future presence of the tower on Zanzibar.
GREEN | Nature has been incorporated as an integral element in the building. The biophilic design approach will allow for direct contact with nature even on the highest floors of the tower. Planters and roof gardens create a green screen filtering the air and enhancing views from the apartments. The soil and plants harvest the rainwater and help to reduce the risks of flooding. Most of all the green atmosphere of the tower increases the quality of living for the residents and their visitors.

TIMBER

ENGINEERED TIMBER | Wood, the oldest building material, is the most sustainable building material. Wood sequestrates carbon while steel and reinforced concrete causing carbon emissions in their production process. Sustainable forestry and the application of wooden materials contribute to a better climate.
Although wood itself has been used throughout history of mankind, engineered timber products entered the market only recently. Innovation in production process and applications of these new timber products are disrupting the conventional construction business and are allowing for more advanced sustainable buildings. Moreover, wood and sustainable forestry have a vast presence in the East-African region.
There is no structural limit to the use of engineered timber elements even in high-rise buildings. The limiting factor currently is the combustible character of the material. Worldwide code requirements are subject to change at this moment to increase the use of timber elements in construction. Research and many build examples have shown that with advanced calculation methods the characteristics of the material and engineered timber products when exposed to fire can be determined and sized to fit building integration. The engineering team on ‘BURJ zanzibar’ includes several stakeholders driving the international research and developments in this field. Their knowledge, combined with the experience of the local authorities, will contribute to the creation of guidelines not only for this project but also for many future projects to follow.

QUALITY | Engineered timber products fulfil the highest quality standards as they are produced within an optimized factory settings. Their rapid assembly on site is comparable to steel structures and characterized by a vast amount of prefabrication off-site. This prefabrication process in a controlled environment also significantly reduces the amount of waste produced in comparison to a conventional building site. The high quality of the surface of exposed timber elements not only creates high-quality internal space but also omits the requirement for additional cladding or plastering. The timber elements allow for a high grade of recycling options for future generations.
‘BURJ zanzibar’ is planned as a hybrid-timber tower. The steel reinforced concrete core allows for fire and life safety standards to meet all current code requirements. The structure around the central core is assembled with glue laminated columns and beams as well as cross laminated slabs.
The interior of the apartments benefits from the natural look of exposed timber elements to add to the living quality. ‘BURJ zanzibar’ will become a new landmark for Zanzibar and beyond not only because of its appearance but even more so because if its construction method. The building will promote the local available wood as the building material of the future and draw attention towards a more sustainable construction while offering living conditions to the highest standards.

「BURJ ZANZIBAR」OMT architects 公式サイト

https://omt-architects.com/work/burj

Leander Moons 公式サイト

http://www.laud.nl/index.html

Birk Heilmeyer Frenzel Architects 公式サイト

https://www.bhundf.com/en/