關于綠色的多元化啟示

張利/ZHANG Li

作者單位：清華大學建筑學院/《世界建筑》

今夏席卷各洲的熱浪再次向我們提示了氣候問題與環境挑戰的存在。事實上，如果在當今世界中尋找最大共識的話，應對氣候變化、阻止環境惡化、走向更加綠色的人類共同未來應是不二之選。

在北京延慶舉行的2019 世界園藝博覽會從策劃之初就把對這一共識的關注與詮釋當成了一個基本的出發點。借助于國家正在積極倡導的新發展理念，北京世園會的建設自始至終貫穿了對綠色共同未來的廣義思考。可以說，除了園藝博覽必然呈現的姹紫嫣紅外，延慶的世園場館（既包括永久的，也包括臨時的）本身也形成了耐人尋味的一個展示主體，集結了多元化的綠色啟示。

再生能源與材料在微觀層面的綠色啟示方面占據了主導地位。如果說主動式技術裝備曾經是綠色建筑的默認解決方案的話——當然考慮到現代城市生活對舒適性的日新月異的需求，這也不足為怪——北京世園會似乎更樂于向人們傳播關于被動式技術與可再生建筑材料的解決方法，畢竟全球資源匱乏的記時表在不停地提示我們留下的時間所剩無幾。從可降解的聚合物到可工業生產的夯土模塊，當代建筑材料隨著與自然的“互動”性似乎正在蠶食傳統的刀槍不入的“耐候性”，成為一種新的建筑材料觀。這其中的一個極致的例子是國際竹藤組織園展館，里面不僅把原竹的使用擴展到了空間的每一個細節，還以此為題進行了一次竹藤建筑的設計與搭建國際競賽。在競賽中我們清晰地看到了竹這樣的可再生建筑材料對傳統建筑學定律的“松綁”，以及由此而來一系列爭論與實驗。

仿生或擬態仍然是中觀層面綠色啟示的主要方式。在建筑史上我們從來不缺乏模擬生物體的邏輯來定義空間、建造建筑的動力。有的時候這種模擬以視覺形像為訴求——包括對招人喜愛的動物和各種花卉的模仿——以建筑的幾何外型為實現手段。有的時候這種模擬則以對能源與物質的循環代謝為訴求，以建筑的建造邏輯或空間邏輯為實現手段。在延慶，我們看到的主要是后者，而靈感的來源主要集中在“樹”和“林”中。國際館最引入注目之處是形成空間——室外和室內——的結構、技術一體化的傘狀單元，它毫不隱晦地指向我們所熟悉的荷葉或闊葉樹木，在完成自然支撐的同時形成受人喜愛的蔭蔽。植物館則更加直白，它不僅干脆以“植物的智慧”為題，更以激進的垂落線條處理，模擬自然樹林中的層次。

對人與自然關系的再思考、以及對自身文化基因中可持續生存方式的再詮釋是宏觀層面上的綠色啟示。在中國舉行的世園會當然要傳播東方的自然哲學，而在已經接近21 世紀第三個10 年的今天，東方傳統的敬讓（而非爭奪）、共生（而非征服）與樸素（而非奢華）的人與自然關系顯然是有突出的意義的。北京世園會選取媯河邊的戍邊、農墾與園藝傳統的區域為會址已經蘊含了這種文化基因，空間規劃上的山水格局、建設上的古家營小鎮復建等也是在延續這一基因。而全園最主要的單體建筑——中國館，更是把這種基因在建筑上的潛力發揮盡致。在這座其外部空間為一完整的微型生態圈的建筑中，從“四水歸堂”“田”概念的使用，到“錦繡如意”的別名，都充盈著東方的田園理想。

我們不得不說，在各種博覽會不絕于耳的今天，因為其對東方傳統與綠色未來的關注，北京世園會還是明顯使我們感到了一絲興意。這也是我們制作此專輯的原因。感謝北京世界園藝博覽會事務協調局與北京世園投資發展有限公司的幫助，是他們使本期《世界建筑》成為可能。

Heatwaves hitting all the continents in the northern hemisphere is just another proof of the biggest challenge we are facing today: climate change and environment. Actually, if there should be one consensus in this turbulent and polarising world, it has to be the willingness for a greener common future.

Since its conceptualisation, 2019 Beijing International Horticultural Exhibition in Yanqing has taken the promoting of such a consensus as its underlying agenda. Vastly helped by the new national development objectives, the planning and construction of Yanqing 2019 has carried out this agenda quite well. Besides all the flamboyance of all horticultural or gardening shows, the architecture of Yanqing 2019, whether permanent or temporary,has become a display of its own right, collecting and disseminating green inspirations in various ways.

At the microcosm level, thoughts of renewables, energy and material, are the dominating inspirations. In the very near past, active building technologies were the default solutions to green buildings, particularly when the demand for everincreasing comfort in contemporary urban life was non-stoppable. Yanqing is claiming a different path. Passive buildings, renewable, or even organic building materials are the things that are being displayed as must-haves. The clock of global resource depletion is clicking after all. In buildings at Yanqing 2019, we see a trend of more natural materials, from degradable polymer to prefab rammed-earth blocks.They are the evidence that a modern"interaction"between the building material and the climate is gradually replacing the traditional "no-interaction"weather proof idea. A eccentric example is the INBAR Garden pavilion. Not only is everything in the pavilion built with bamboo, but also an international student competition for bamboo building is featured, where three student projects got built. We see clearly signs of architectural orthodoxies being dismantled by the use of organic materials, and all related debates and inquiries coming after.

B iomimc ism, and to a less er ex tent anthropomorphism, is still the main inspiration at the intermediate level. In the history of architecture,there has never been a lack of stimulation to mimic the physical or generative logic of a beloved creature. At certain periods this mimicism is purely about form, such as all kinds of good-looking animals and flowers. At certain periods it is more about metabolism, cycles of energy and materials.In Yanqing it is the latter, with the source of mimicking being mainly trees and forests. The entire International Pavilion is covered with the umbrella unit, which mimics a lotus or a deciduous tree with its structure not only supporting its weight but also creating a welcoming shade. The Botanic Garden is even more explicit. With the name "the wisdom of plants", and its radically redundant hanging vertical elements, the image of a layered forest is made.

At the macro level, the inspirations have much deeper culture roots. It is the rethinking of man and nature, and the reinterpretation of traditional cultural genes. Make no mistake that at a horticultural expo in China, you do expect some interpretation of oriental natural philosophies.You won't be disappointed. The oriental yielding(rather than competing), co-habiting (rather than conquering), and frugality (rather than luxury) have all been interpreted, all in a very demanding 3rddecade-of-the-21st-century context. The site of Yanqing 2019 used to be riverside strip for border farming and gardening. The masterplan of Yanqing 2019 meticulously implemented the Shanshui theories in full. The remake of gardening villages such as Gujiaying helps to revive the gardening tradition and life style. And above all, the most important building of the entire expo, the China Pavilion, also covers in great depth the issue of oriental natural philosophies. The master plan is inspired by a typical Chinese farming house. The use of terraced farmlands and the collection of rain waters are all new incarnations of very ancient ideas.Even the nickname, "the bountiful land" echoes some truly idyllic traditional ideals.

We have to admit that at a time of a plethora of expos every day, Yanqing 2019 is refreshing in the way it explores and informs about the green future. It is because of this that we make this special number of WA. Our sincere thanks to the Beijing Horticultural Exhibition Coordination Bureau, and Beijing Shiyuan Investment Co., Ltd., who have made this special number possible.