关于绿色的多元化启示

张利/ZHANG Li

作者单位：清华大学建筑学院/《世界建筑》

今夏席卷各洲的热浪再次向我们提示了气候问题与环境挑战的存在。事实上，如果在当今世界中寻找最大共识的话，应对气候变化、阻止环境恶化、走向更加绿色的人类共同未来应是不二之选。

在北京延庆举行的2019 世界园艺博览会从策划之初就把对这一共识的关注与诠释当成了一个基本的出发点。借助于国家正在积极倡导的新发展理念，北京世园会的建设自始至终贯穿了对绿色共同未来的广义思考。可以说，除了园艺博览必然呈现的姹紫嫣红外，延庆的世园场馆（既包括永久的，也包括临时的）本身也形成了耐人寻味的一个展示主体，集结了多元化的绿色启示。

再生能源与材料在微观层面的绿色启示方面占据了主导地位。如果说主动式技术装备曾经是绿色建筑的默认解决方案的话——当然考虑到现代城市生活对舒适性的日新月异的需求，这也不足为怪——北京世园会似乎更乐于向人们传播关于被动式技术与可再生建筑材料的解决方法，毕竟全球资源匮乏的记时表在不停地提示我们留下的时间所剩无几。从可降解的聚合物到可工业生产的夯土模块，当代建筑材料随着与自然的“互动”性似乎正在蚕食传统的刀枪不入的“耐候性”，成为一种新的建筑材料观。这其中的一个极致的例子是国际竹藤组织园展馆，里面不仅把原竹的使用扩展到了空间的每一个细节，还以此为题进行了一次竹藤建筑的设计与搭建国际竞赛。在竞赛中我们清晰地看到了竹这样的可再生建筑材料对传统建筑学定律的“松绑”，以及由此而来一系列争论与实验。

仿生或拟态仍然是中观层面绿色启示的主要方式。在建筑史上我们从来不缺乏模拟生物体的逻辑来定义空间、建造建筑的动力。有的时候这种模拟以视觉形像为诉求——包括对招人喜爱的动物和各种花卉的模仿——以建筑的几何外型为实现手段。有的时候这种模拟则以对能源与物质的循环代谢为诉求，以建筑的建造逻辑或空间逻辑为实现手段。在延庆，我们看到的主要是后者，而灵感的来源主要集中在“树”和“林”中。国际馆最引入注目之处是形成空间——室外和室内——的结构、技术一体化的伞状单元，它毫不隐晦地指向我们所熟悉的荷叶或阔叶树木，在完成自然支撑的同时形成受人喜爱的荫蔽。植物馆则更加直白，它不仅干脆以“植物的智慧”为题，更以激进的垂落线条处理，模拟自然树林中的层次。

对人与自然关系的再思考、以及对自身文化基因中可持续生存方式的再诠释是宏观层面上的绿色启示。在中国举行的世园会当然要传播东方的自然哲学，而在已经接近21 世纪第三个10 年的今天，东方传统的敬让（而非争夺）、共生（而非征服）与朴素（而非奢华）的人与自然关系显然是有突出的意义的。北京世园会选取妫河边的戍边、农垦与园艺传统的区域为会址已经蕴含了这种文化基因，空间规划上的山水格局、建设上的古家营小镇复建等也是在延续这一基因。而全园最主要的单体建筑——中国馆，更是把这种基因在建筑上的潜力发挥尽致。在这座其外部空间为一完整的微型生态圈的建筑中，从“四水归堂”“田”概念的使用，到“锦绣如意”的别名，都充盈着东方的田园理想。

我们不得不说，在各种博览会不绝于耳的今天，因为其对东方传统与绿色未来的关注，北京世园会还是明显使我们感到了一丝兴意。这也是我们制作此专辑的原因。感谢北京世界园艺博览会事务协调局与北京世园投资发展有限公司的帮助，是他们使本期《世界建筑》成为可能。

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.