古斯塔夫·安布羅西尼，圭多·卡萊加里/Gustavo Ambrosini, Guido Callegari

尚晉 譯/Translated by sHANG Jin

屋頂景觀再利用策略介紹

古斯塔夫·安布羅西尼，圭多·卡萊加里/Gustavo Ambrosini, Guido Callegari

尚晉 譯/Translated by sHANG Jin

Roofscapes Redevelopment strategies: An introduction

屋頂作為主要的傳統(tǒng)建筑元素之一，在今天關(guān)于城市肌理的彈性及以降低環(huán)境影響和資源浪費(fèi)為目標(biāo)、更加可持續(xù)的發(fā)展模式的語(yǔ)境下，它的潛力得到了新的關(guān)注。

一方面，20世紀(jì)末對(duì)土地消耗策略及大城市社區(qū)價(jià)值衰退的影響等風(fēng)險(xiǎn)的意識(shí)不斷提高，引起了對(duì)城市蔓延政策的警覺；這種態(tài)度在很大程度上源于對(duì)大尺度城市模型的批判，并通過劉易斯·芒福德、讓·戈特曼、簡(jiǎn)·雅各布斯等人的巨著在1960年代的北美興起。如今，一種以所謂的“緊縮城市”模型為基礎(chǔ)的討論方興未艾，反映出日益高漲的需求：約束土地消耗、追求適合社會(huì)多樣性的環(huán)境和更加可持續(xù)的交通發(fā)展體系。近來關(guān)于密集化的許多政策都對(duì)屋頂給予了特別關(guān)注，將其視為作為一種“空中花園”，并考察了其在支撐（適度）城市擴(kuò)展、為新功能或綠地增加面積上的可能性。

另一方面，普通低品質(zhì)住房的翻修成了一個(gè)迫切的城市問題。這是一種相當(dāng)普遍的現(xiàn)象，而在歐洲戰(zhàn)后工業(yè)大發(fā)展時(shí)期建成的公共住宅區(qū)尤為突出：其保護(hù)狀況普遍很差，立面和窗戶缺少保溫，需要安裝主動(dòng)和被動(dòng)節(jié)能系統(tǒng)等。因此近幾年建筑語(yǔ)匯中就涌現(xiàn)出一個(gè)新的術(shù)語(yǔ)：翻新。為提高能效對(duì)現(xiàn)有建筑進(jìn)行的翻新似乎把建筑性能當(dāng)成了一個(gè)單純的技術(shù)問題：為了避免不同的態(tài)度，建立一種能將技術(shù)與建筑個(gè)性結(jié)合在一起的包容性方法成了最前沿的挑戰(zhàn)。在很多情況下，屋頂會(huì)經(jīng)過多次重大改造，涉及到材料、功能和造型：建筑的頂蓋往往會(huì)在兼顧改善能效和運(yùn)行性能與增加住房數(shù)的策略中發(fā)揮關(guān)鍵作用。新增住宅單元帶來的經(jīng)濟(jì)收益會(huì)允許較高的翻新成本。

最近不少研究考查了屋頂擴(kuò)建策略的成本收益，比如歐盟委員會(huì)推廣的歐洲高層社會(huì)住宅的可持續(xù)屋頂擴(kuò)建翻新（SURE-FIT）就是為了評(píng)估新的利用方式在解決節(jié)能問題上的效果。評(píng)估的同時(shí)還建立了步驟模型和實(shí)施導(dǎo)則，并考慮了可行性、產(chǎn)權(quán)、結(jié)構(gòu)荷載、參與者等基本問題。這些因素統(tǒng)籌在一起就形成了最初的干預(yù)體系，它集中在三大建筑策略上：對(duì)比——新的體形表達(dá)出與下方建筑特征相對(duì)的獨(dú)立性；擴(kuò)展——新建部分表現(xiàn)為原始部分的延伸，并充分尊重其建筑特色；融合——擴(kuò)建涉及到建筑整體或局部的改造，將以統(tǒng)一的手法對(duì)新舊部分進(jìn)行更新。

在這種框架下，最近的屋頂擴(kuò)建項(xiàng)目會(huì)展現(xiàn)出多種多樣的方法：本期的目的就是將其精要呈現(xiàn)出來，聚焦突破城市特性再造的各種方式。

對(duì)近期案例研究的考察將會(huì)找到反復(fù)出現(xiàn)的論題。

傳統(tǒng)城市肌理中的屋頂再設(shè)計(jì)會(huì)帶來一種微妙的變化：即使是微不足道的擴(kuò)建也應(yīng)針對(duì)空間和建造的問題，以突破城市住宅宜居概念的界限。它也應(yīng)是一種更重要的充實(shí)建筑體的過程，通過內(nèi)部“發(fā)掘”實(shí)現(xiàn)全面翻修。

屋頂再設(shè)計(jì)能夠滿足戰(zhàn)后住區(qū)能效和功能日益增長(zhǎng)的需求，并在保留原有結(jié)構(gòu)的同時(shí)為增加新功能的面積創(chuàng)造機(jī)會(huì)。它意味著能為停滯不前的住區(qū)增加一種層次化的城市個(gè)性，比如高大樸素的公共住宅樓。新的預(yù)制干做法等先進(jìn)技術(shù)為創(chuàng)新性干預(yù)提供了新的資源。

屋頂再設(shè)計(jì)往往在工廠的翻修過程中具有重要作用，有時(shí)還是其中的點(diǎn)睛之筆。赫爾佐格和德梅隆事務(wù)所的很多項(xiàng)目都是生動(dòng)的例子。比如，他們擴(kuò)建的屋頂以一個(gè)“夜明塔”作為倫敦泰特現(xiàn)代美術(shù)館厚重磚建筑之上輕盈的終止符，為人們?cè)趨⒂^結(jié)束時(shí)舉行集會(huì)并欣賞開闊的城市景觀提供了休憩空間。他們還在馬德里電廠的厚重體塊上用鑄鐵進(jìn)行了具有戲劇效果的擴(kuò)建。其目的是以一種看似不可能的方式與下方挖出的空間構(gòu)成均衡的態(tài)勢(shì)，從而在新的馬德里當(dāng)代藝術(shù)博物館內(nèi)部營(yíng)造出一個(gè)連續(xù)流動(dòng)的空間。最后一個(gè)例子在漢堡港，他們利用一座舊倉(cāng)庫(kù)創(chuàng)造出了全新的城市地標(biāo)（易北愛樂廳項(xiàng)目）。

這些不過是冰山一角，卻已折射出建筑順應(yīng)變化條件、增強(qiáng)城市建成環(huán)境彈性的能力。□

1 林格托區(qū)/Lingotto district

2 馬賽公寓/Unité d' Habitation, Marseille

The potentiality of one of the main traditional architectural elements – the roof – is gaining a renewed limelight in present time discourse on the resilience of urban fabric and on more sustainable development models aiming at reducing environmental impacts and the waste of resources.

On the one hand, at the end of the 20th century the increasing awareness about the risks of land consuming strategies and of the impoverishment affecting the values in metropolitan communities' has fostered a warning towards urban sprawl policies. It is a point of view that owes so much to the criticism against large scale urban models, which arose in North America in the 1960s, thanks to the seminal works of Lewis Mumford, Jean Gottmann, Jane Jacobs and other authors. Nowadays, a narrative based on the so-called "compact city" model is rising,as a response to the growing need to limit land consumption, as well as a condition for ensuring social diversity and more sustainable systems of transport development. In recent densification policies a special attention is paid to the roof as a sort of "raised ground", checking its availability to support a (moderate) city extension, adding extra floor space for new functions or greenery.

On the other hand, the renovation of ordinary low quality housing stock constitutes one of the main urgent urban issues. It is a widely diffused phenomenon, more evident in European public housing districts built during the post-war industrial boom: general bad state of conservation, lack of thermal insulation of facades and windows, need to install active and passive energy saving systems etc.Therefore a new term has burst in the architectural vocabulary in recent years: retrofit. The action of retrofitting existing buildings in order to improve energy efficiency seems to put the accent on the performance of the building as a mere technological matter: in order to avoid a separate attitude,the setting out of an inclusive approach, able to assimilate technical items into the architectural identity issue represents an up-to-date challenge.In many cases, the roof undergoes great changes,regarding materials, function, shape: the cover of the buildings often plays a key role in strategies aimed at joining the improvement of energy and functional performances with the increase of the number of dwellings. The economic increment deriving from new housing units additions should allow to undertake high retrofit costs.

Cost-effective implications of roof top extension strategies have been investigated by recent research programmes, like SURE-FIT (Sustainable Roof Extension Retrofit for High-Rise Social Housing in Europe) promoted by the European Commission,in order to assess the meeting of new exploitation with energy conservation issues. The evaluation accompanied the setting up of procedural models and guidelines for realisation, taking into account basic questions as feasibility, property rights,structural loads, actors etc. Along with this, a first taxonomy of interventions emerged, envisaging three main somewhat general architectural strategies: "contrast", when the new volumes express an autonomous identity counterpointing the below architectural features; "expansion", when the new add-on appears as an extension of the original part, fully respecting its architectural characters;"integration", when the extension involves a complete or partial transformation of the building,renewing both the existing part and the new one in the same way.

In this framework, the recent rooftop extension projects should unveil a multiplicity of approaches:the aim of the present issue is to illustrate some of them, in order to highlight several ways to challenge the reinvention of urbanity characters.

A survey among recent case studies can define some recurring topics.

Rooftop re-design inside the traditional urban fabric should generate a subtle change: even a scarcely considerable extension should match spatial and constructive issues in order to push the limits of liveability concept of urban dwelling. It should be a more substantial process of infilling the building body too, "excavating" inside it, leading to a complete renovation.

3 倫敦泰特現(xiàn)代美術(shù)館/Tate Modern, London（1-3攝影/Photos: G. Ambrosini）

Rooftop re-design could meet the growing need to improve energy and functional performance of post-war neighbourhoods, offering the opportunity to add floor space for new functions while keeping existing structures. It implies the possibility to add a layered city identity to those settlements apparently sentenced to a static feature, such as massive blank public housing estates. Cutting-edge technologies,such as new prefabricated dry systems, offer new resources for innovative interventions.

Rooftop re-design often plays an important role, sometimes the most eye-catching component,of factory renovation processes. Some Herzog &De Meuron's projects offer vivid examples. For instance, when a rooftop addition gently completes the heavy mass of the brick Tate Modern in London through a bright "body of light", luminous at night,providing the rest spaces where people gather at the end of the visit and a spectacular open view towards the town. Or when it shapes a dramatic cast iron addition on the heavy mass of Central Eléctrica in Madrid aiming at counterbalancing, in a seemingly impossible way, the below excavation that generates a continuous flowing space inside the new Caixa Forum museum. Or, finally, when it assumes(in the project for the Elbphilharmonie) a former warehouse in Hamburg harbour as a foundation for a bright new urban landmark.

These are some clues, among others, able to show architecture's capacity to adapt to changing conditions and to enhance the resilience of urban built environment. □

都靈理工大學(xué)

2017-10-18