大都會(huì)大廈有多高
——一座轉(zhuǎn)換為住宅的布魯塞爾辦公樓

亞歷山德羅·波洛托

1 鳥瞰Aerial view

在建筑上建造的一種實(shí)際方式：對(duì)普通建筑的改寫

當(dāng)代設(shè)計(jì)越來越多地將老舊建筑更新作為一種學(xué)術(shù)研究和當(dāng)前專業(yè)實(shí)踐的主要工具。在西方國家，迅速衰敗的現(xiàn)代建筑帶來了一個(gè)必要而緊迫的問題：對(duì)普遍存在的質(zhì)量較差（甚至極糟）的建筑遺產(chǎn)進(jìn)行再利用。環(huán)境問題使設(shè)計(jì)師和城市管理者很少能像不久前那樣，根據(jù)建筑的美學(xué)特性或設(shè)計(jì)者身份來選擇保護(hù)和改造的對(duì)象，這一轉(zhuǎn)變在歐洲尤為顯著。所有現(xiàn)存的建筑都傾向于再生而非拆除和重建，所產(chǎn)生的建筑殘骸也被納入一個(gè)良性的經(jīng)濟(jì)循環(huán)過程。

同時(shí)，在過去兩年中，對(duì)生活和工作空間的評(píng)價(jià)和重組的需求增加了。新冠疫情和偶發(fā)的能源危機(jī)推動(dòng)了智能化辦公模式的發(fā)展，許多辦公大樓被廢棄和閑置，影響甚至破壞了整個(gè)城市片區(qū)的形象。

在這些前提下，基于對(duì)當(dāng)前設(shè)計(jì)實(shí)踐的觀察而重新思考“在建筑上做建筑”這一理論，使得對(duì)“作品”式建筑的干預(yù)愈發(fā)沒有吸引力，因其通常受到許多限制；反而是對(duì)普通建筑的“改寫”激發(fā)了在類型學(xué)、構(gòu)成、形式、裝飾和空間質(zhì)量上變革的潛力。

通過比較最近的兩個(gè)項(xiàng)目可以證實(shí)上述觀點(diǎn)。這兩個(gè)項(xiàng)目都是1960 年代設(shè)計(jì)文化的遺產(chǎn)，它們既相似又對(duì)立：一個(gè)是由馬塞爾·布魯爾在紐黑文設(shè)計(jì)的著名的倍耐力輪胎辦公樓改造而成的酒店；另一個(gè)是亞歷山德羅·波洛托所介紹的由BOGDAN &VAN BROECK 事務(wù)所對(duì)布魯塞爾大都會(huì)大廈（圖1）的改造。在第一個(gè)案例中，外墻被理解為不可改變的表皮，對(duì)設(shè)計(jì)產(chǎn)生了很大約束，該項(xiàng)目局限于重新安排內(nèi)部空間，未能充分利用為獲得被動(dòng)式建筑認(rèn)證而采取的技術(shù)手段的潛在表現(xiàn)力。與之相對(duì)的，BOGDAN &VAN BROECK 的項(xiàng)目是一個(gè)良性改造的程序性示例：原來的無名辦公大樓僅保留了鋼筋混凝承重框架，對(duì)其加固后又在上方加建3 層。如果拆除整個(gè)建筑，那么建造成本、能源消耗、廢棄物以及由制造和運(yùn)輸新材料所產(chǎn)生的碳排放都會(huì)增加。在拆除原來的外墻后，建筑師在原有框架上搭建新的鋼骨架，用以承托加建的巨大外廊。外廊不僅遮蔽了陽光和風(fēng)，還成為我們這個(gè)時(shí)代發(fā)揮建筑表現(xiàn)潛力的典范，是周期性變化的階段、創(chuàng)作者、需求和意義的產(chǎn)物。(阿爾貝托·博洛尼亞 文)

The Actual Way of Building upon Building:Overwriting on Ordinary Architecture

Contemporary design culture is,increasingly,placing the issue of overwriting the existing architecture over time as one of the main tools in both academic research and current professional practice.Modern architecture,due to its rapid decay,is posing a necessary and urgent problem with great strength in the West:the regeneration of a widespread heritage,often consisting of buildings of limited (or even absent) architectural quality.Compared to the more recent past,especially in Europe,environmental issues have increasingly confronted designers and city administrators with the situation where it is no longer possible to choose buildings to preserve and transform on the basis of their aesthetic peculiarities or authorship.All the existing building stock tends to be regenerated,rather than demolished and rebuilt,and the rubble produced fed into a virtuous circular economy process.

At the same time,the past two years have accelerated the need for a review and reorganisation of both living and work spaces:the COVID-19 pandemic and the contingent energy crisis are amplifying smart working arrangements,making much of the office buildings obsolete and unused,evolving (or,even,undermining) the identity of entire urban neighbourhoods.

On these premises,the rethinking of a theory of the so-called "building upon building" based on the observation of current design practice makes the interventions on "auteur" architecture less and less attractive because of the constraints to which it is normally subjected;on the other hand,thetransformative potential on the typological,compositional,formal,ornamental,and spatial quality genesis levels arising from overwriting operations on ordinary buildings emerges.

2 BOGDAN &VAN BROECK事務(wù)所改造 前后的對(duì)比The high-rise building before and after the BOGDAN &VAN BROECK's project

3 街景Street view

4 公共人行道Public pedestrian path

5 保留的混凝土框架Preserved concrete skeleton

在布魯塞爾的中心地帶，有一個(gè)建于中世紀(jì)、服務(wù)于當(dāng)時(shí)港口貿(mào)易的老碼頭區(qū)，其間一座灰色的高層建筑拔地而起，破壞了當(dāng)?shù)氐某鞘薪Y(jié)構(gòu)。它是Assubel 保險(xiǎn)公司的總部，建于1960年代。20 世紀(jì)下半葉，城市辦公空間急速增長，而今天的趨勢是商業(yè)區(qū)的去密度化[1]。

新的城市計(jì)劃力圖推動(dòng)布魯塞爾空置辦公樓的用途轉(zhuǎn)換，背后的主要原因包括：金融危機(jī)對(duì)商業(yè)房地產(chǎn)行業(yè)的影響，各大公司可使用新的數(shù)字技術(shù)和遠(yuǎn)程通信工具，以及由此造成的人均辦公空間的減少，經(jīng)濟(jì)、服務(wù)和基礎(chǔ)設(shè)施的共享趨勢（例如聯(lián)合辦公空間），市中心住宅開發(fā)項(xiàng)目的用地短缺，以及由于人口增長帶來的對(duì)城市住房的大量需求[2]。

2014年，建筑公司BOGDAN &VAN BROECK 的項(xiàng)目大都會(huì)大廈在Besix RED 地產(chǎn)公司組織的邀請(qǐng)賽中勝出。這座空置10 余年的灰色高層建筑被重新設(shè)計(jì)成一座住宅樓（圖2）。它被保留并加建了3層，總共16層，在老碼頭和運(yùn)河街上矗立（圖3）。在場地的東南角又新建一棟5層高的建筑，使高層建筑與鄰近排屋之間的過渡更加平滑。項(xiàng)目共含156 套住宅。

底層由V 形柱界定的兩條公共柱廊提供了穿越場地的廊下通道（圖4）。減少停車位的數(shù)量以便留出綠化空間，提倡可持續(xù)的公共交通、自行車或其他靈活交通方式。該項(xiàng)目最終設(shè)置了供170 輛自行車和50 輛汽車使用的停車位。

高層建筑原有的混凝土骨架被保留下來并嚴(yán)格加固，以便承托加建的3 層。這種通常用于辦公樓的混凝土承重結(jié)構(gòu)提供了更多自由的空間，樓層之間的高度超過3m，適應(yīng)于住宅或混合功能（圖5）。一二層容納了貫穿南北的聯(lián)合辦公空間（圖6），中間有一個(gè)雙層通高的門廳和原位保留的垂直交通核。

其他樓層共可容納130 個(gè)居住單元。因保留了南側(cè)樓梯井，各層的中央走廊串起兩側(cè)的公寓。住宅均為單向，并采用了基于混凝土框架尺寸的模塊化方案。模塊的組合能夠創(chuàng)造出豐富的類型，包括小型住宅單元，如工作室和一居室公寓（圖7），包含3 間臥室的大戶型公寓（圖8），以及頂層的兩套閣樓公寓。

原有的灰色混凝土外墻被拆除，取而代之的是一個(gè)新的、類似于白色腳手架的鋼結(jié)構(gòu)，長度貫穿東西立面，為所有的公寓提供1.8m 寬的露臺(tái)（圖9）。這些露臺(tái)配備了可滑動(dòng)的白色穿孔板，屏蔽陽光和風(fēng)的同時(shí)創(chuàng)造了一個(gè)獨(dú)特的構(gòu)圖，成為布魯塞爾天際線上的一個(gè)標(biāo)志。

大都會(huì)大廈于2019 年竣工，其名字所隱含的國際愿望已經(jīng)實(shí)現(xiàn)——該項(xiàng)目獲得“2022 年Archdaily 年度建筑獎(jiǎng)”提名與2022 年“歐盟當(dāng)代建筑獎(jiǎng)——密斯·凡·德羅獎(jiǎng)”，并被特別提名為“2021 年辦公建筑改造住宅類國際大獎(jiǎng)”。

大都會(huì)大廈的改造表明，危機(jī)可能導(dǎo)致建筑的衰敗和空置，但也為住房設(shè)計(jì)和城市生活提供了機(jī)會(huì)。作為由戰(zhàn)后辦公建筑改造成住房的典例，它豐富了可持續(xù)發(fā)展倡議的內(nèi)容。

由于原來的混凝土結(jié)構(gòu)含有大量石棉，拆除高層建筑并重建的成本本應(yīng)更低。但精確的計(jì)算證實(shí)了保留原有的混凝土結(jié)構(gòu)會(huì)降低建筑成本、能源消耗，減少拆除廢棄物以及在制造和運(yùn)輸建筑材料時(shí)的碳排放[3]。

6 首層平面Ground floor plan

7 二層平面First floor plan

8 十一層平面Tenth floor plan

Two recent projects,at once similar and antithetical,both legacies of the 1960s design culture,can be compared to support this claim:the transformation into a hotel of the famous Pirelli Tire office building,a Marcel Breuer's masterpiece in New Haven,and the intervention presented here by Alessandro Porotto by the firm BOGDAN &VAN BROECK on the Cosmopolitan tower (Fig.1) in Brussels.In the first case,the rigid constraint of understanding the fa?ade as an unalterable external skin limited the design challenges:the project is confined to the rearranging of interior spaces,without harnessing the possible expressive potential of the technical arrangements adopted to achieve Passivhaus certification.Instead,BOGDAN &VAN BROECK's project can be considered a programmatic example of virtuous overwriting:from the original anonymous office building,only the reinforced concrete load-bearing framework was retained,strengthened to allow the addition of three new floors.A total demolition would have caused higher construction costs,energy consumption,waste generation as well as CO2 emissions due to the manufacture and transportation of the new materials.Having removed the original fa?ade,the architects thus overwrote the framework with a new steel skeleton to accommodate large loggias that,in addition to protecting from sun and wind,becomes paradigmatic of the expressive potential of an architecture of our time that is the outcome of cyclically changing phases,authors,needs and meanings.(Text by Alberto Bologna)

Located in the heart of Brussels,a grey high-rise volume rose up from the old quay district,which was originally built in the Middle Ages for the erstwhile trading harbour.Constructed in the 1960s,this building disrupted the local urban fabric in order to accommodate the headquarter of the Assubel insurance company.While a sharp increase in office spaces occurred in the second half of the 20th century,today the trend is the de-densification of business districts[1].

The impact of the financial crisis on the commercial real estate sector,new digital technologies and remote communication tools for companies,the resulting reduction of office space per employee,the diffusion of shared economies,services,and infrastructure– for instance,in the form of coworking spaces– the shortage of project sites in central areas for residential real estate development,and the high demand for housing in urban areas due to population growth are some of the main developments that drove new urban initiatives for the conversion of unoccupied office buildings in Brussels[2].

In 2014,architectural firm BOGDAN &VAN BROECK's project The Cosmopolitan was selected for an invited competition organised by the client Besix RED.The grey high-rise building,unoccupied for over 10 years,was redesigned to be converted into a residential tower (Fig.2).Standing perpendicular to the old docks and the rue du Canal,it was preserved and extended with three floors,for a total of 16 (Fig.3).At the south-east corner of the site,a new five-floor building was added to smooth the transition from the high-rise to the neighbouring row-houses.The final project includes 156 dwellings.

Two public colonnades with double-height diagonal pillars running along the lower floors define the sheltered pedestrian path crossing the site (Fig.4).The number of parking spaces are reduced to make space for greenery and encourage sustainable public transport,cycling,or soft mobility.There are thus parking spaces for 170 bicycles and 50 cars.

Looking at the high-rise building itself,the existing concrete skeleton was preserved and rigorously reinforced to allow the addition of three floors.This regular concrete load-bearing structure typically used for office buildings offered a freely adaptable space with a height of over three metres between floors,easily adapted for housing and mixed-use purposes (Fig.5).The ground and first floors accommodate co-working office spaces to the north and south (Fig.6).In between,a double-height access hall serves the main vertical distribution core,the original position of which was preserved.

The other floors accommodate a total of 130 units.Given the preservation of the south stairwell,each floor is organised around a central corridor with apartments on either side.For this reason,the dwellings are all mono-oriented and adopt a pragmatic scheme based on the modular dimensions of the concrete structure.A typological combination has nevertheless been established,and one can find small housing units,such as studios and one-bedroom apartments (Fig.7),as well as larger apartments of up to three bedrooms (Fig.8) and two penthouses on the top floor.

The existing grey concrete fa?ade was removed.This was replaced by a new,white scaffold-like steel structure supporting 1.8 m-wide terraces for all apartments along the entire length of the east and west fa?ades (Fig.9).These terraces are equipped with white perforated sliding panels as protection from sun and wind while also creating a unique composition that has become a landmark on Brussels' skyline.

Completed in 2019,the international aspirations implied by the name The Cosmopolitan were achieved when the project was nominated for the ArchDaily 2022 Building of the Year Awards,for the EU Prize for Contemporary Architecture– Mies van der Rohe Award 2022,and awarded a special mention by the jury for the Prix international de la transformation de bureaux en logements 2021.

The Cosmopolitan reveals that a crisis situation can lead to building deterioration and vacancy but also presents opportunities for housing design and urban living.It establishes the ingredients of the cocktail for sustainable initiatives to convert post-war office buildings into housing.

Since the original concrete structure was riddled with asbestos,it would have been cheaper to demolish the high-rise building and start anew.Accurate calculations confirmed that the preservation of the original concrete structure would have lower construction costs,use less energy,and generate less demolition waste as well as fewer CO2emissions in the manufacture and transportation of building materials[3].

Furthermore,the reuse of the existing skeleton allowed for an adaptable plan which can accommodate a mixed-use project with housing and co-working spaces.In line with theBrussels 2040goals and urban strategies undertaken by the Brussels-Capital Region,reconversion projects are among the most suitable tools to foster mixed-use design against the urban monofunctionality characterising post-war developments[4].Besides increasing the number of dwellings and residents,The Cosmopolitan creates a strong connection between housing and workplace,which acts as a driving force for densification and stimulates the urban economy on a neighbourhood scale.One possible reason behind the acceleration of these strategies is the perpetuation of forms of work associated with housing on a large scale,a process that has definitively been expedited by the COVID-19 pandemic.

In addition to high densification in terms of surfaces,purposes,and inhabitants,the reconversion of unoccupied buildings such as The Cosmopolitan is specifically involved in a discourse of open spaces.Since land for new urban developments is scarce in Brussels,high-rise buildings create an urban compactness that prevents the disappearance of urban open spaces.While public and green areas are more and more embedded in contemporary housing projects,spaces for residents such as terraces and loggias are becoming ever more crucial[5],especially in light of the challenging lockdown circumstances caused by the COVID-19 pandemic.It is no coincidence that in The Cosmopolitan the large terraces improve the quality of domestic space for all apartments (Fig.10).Recent trends in housing design and the COVID-19 outbreak emphasised the need for experimentation in terms of architectural design and typology to meet contemporary ecological challenges.Diversified dwelling types combining outdoor spaces are therefore crucial to create the conditions for a sustainable and liveable city.

The Cosmopolitan stands alongside the dominant maisons bruxelloises– Brussels terraced houses with private gardens forming close urban blocks– the 19th-century Grand Hospice,and the former Beguine convent neighbourhood.This high-rise housing project stresses the fact that the contemporary city is built continuously on a palimpsest[6].In addition to these past layers,the conversion of vacant office buildings into housing has a considerable resilient impact on the urban built environment as well as on housing typologies.While it values the memory of post-war architecture,it improves the quality of living in a sustainable and densely populated contemporary city facing future challenges.Located in the heart of Brussels,the white high-rise volume of The Cosmopolitan defines a new strategy for urban housing to accommodate the evolving urban and socio-cultural identity of the Brussels-Capital Region.□

9 立面鋼結(jié)構(gòu)細(xì)部Detail of the fa?ade's steel structure

10 公寓的起居室和露臺(tái)Living space and terrace of an apartment

此外，被保留的原有框架提供了一個(gè)具有適應(yīng)性的平面，可以滿足居住和聯(lián)合辦公的混合用途。根據(jù)《布魯塞爾2040》中提到的目標(biāo)和布魯塞爾—首都區(qū)的城市戰(zhàn)略，功能轉(zhuǎn)換項(xiàng)目是促進(jìn)混合用途設(shè)計(jì)最合適的工具之一，以反對(duì)戰(zhàn)后城市功能單一的發(fā)展模式[4]。除了增加住宅和居民的數(shù)量，大都會(huì)大廈還在住房和工作場所之間建立了強(qiáng)有力的聯(lián)系以推動(dòng)密集化，并在街區(qū)范圍內(nèi)刺激城市經(jīng)濟(jì)。這些策略背后，一個(gè)可能的動(dòng)因是居家工作模式的普遍化。該過程無疑被新冠疫情加速了。

除了在表皮、用途和居民方面的高度密集化之外，像大都會(huì)大廈這樣的閑置建筑更新也涉及到對(duì)開放空間的討論。布魯塞爾新的城市發(fā)展用地稀缺，而高層建筑能提高城市的緊湊性，防止城市開放空間消失。公共和綠色區(qū)域正越來越多地嵌入到當(dāng)代住房項(xiàng)目中，與此同時(shí)，居民的個(gè)人開放空間（例如露臺(tái)和涼廊）也變得越來越重要[5]，特別是在新冠疫情造成的環(huán)境封鎖下。在大都會(huì)大廈中，大露臺(tái)提高了所有公寓的居住空間質(zhì)量也就并不意外了（圖10）。最近的住房設(shè)計(jì)趨勢和疫情的爆發(fā)推動(dòng)了應(yīng)對(duì)當(dāng)代生態(tài)挑戰(zhàn)的建筑設(shè)計(jì)和類型學(xué)的實(shí)驗(yàn)。因此，與室外空間結(jié)合的多樣化住宅類型對(duì)于創(chuàng)造可持續(xù)發(fā)展和宜居城市而言至關(guān)重要。

大都會(huì)大廈毗鄰占據(jù)主導(dǎo)的“布魯塞爾式住宅”（布魯塞爾帶有私人花園的排屋，形成緊密的城市街區(qū)）、19 世紀(jì)的大安養(yǎng)院和前貝古女修道院街區(qū)。這個(gè)高層住宅項(xiàng)目強(qiáng)化了這樣一種現(xiàn)實(shí)，即當(dāng)代城市是通過重寫不斷疊加的[6]。除了這些過去的層次，將空置的辦公樓改造成住房，對(duì)城市建筑環(huán)境以及住房類型都有可觀的彈性影響。在重視戰(zhàn)后建筑記憶的同時(shí)，它也提高了在可持續(xù)、人口密集且面對(duì)未來挑戰(zhàn)的當(dāng)代城市中的生活質(zhì)量。位于布魯塞爾市中心的大都會(huì)大廈是一種新的城市住房策略，能夠適應(yīng)布魯塞爾—首都區(qū)不斷發(fā)展的城市和社會(huì)文化形象?！?/p>