What if architects could build living systems rather than static buildings-dynamic structures that modify their internal and external forms in response to changes in their environment? This provocative idea is making waves in the field of architecture. Houses, for example, might shrink in the winter to reduce surface area and volume, thus cutting heating costs. They could cover themselves to escape the heat of the summer sun or shake snow off the roof in winter. Skyscrapers could alter their aerodynamic profiles, swaying slightly to distribute increased loads during hurricanes. Office buildings could reconfigure themselves to improve ventilation.
　　Such "responsive architecture" would depend on two sorts of technology: control systems capable of deciding what to do, and structural components able to change the building's shape as required. Architects have been working to improve the control systems in buildings for many years, but shape shifting technology is at a much earlier stage of development.
　　One approach being pursued by researchers is to imitate nature. Many natural constructions, including spiders' webs and cell membranes, are "tensegrity systems"-robust structures made up of many interconnected elements which can be manipulated to change shape without losing their structural integrity. "These structures can bend and twist, but no element in the structure bends and twists," says Robert Skelton of the Structural Systems and Control Laboratory at the University of California in San Diego. "It's the architecture of life."
　　While Dr Skelton is working on solving the engineering equations associated with tensegrity systems, Tristan d'Estrée Sterk at the Office for Robotic Architectural Media & the Bureau for Responsive Architecture, an architectural practice based in Vancouver, Canada, has begun to construct prototypes of shapechanging "building envelopes" based on tensegrity structures. Lightweight skeletal frameworks, composed of rods and wires and controlled by pneumatic "muscles", serve as the walls of a building; adjusting their configuration changes the building's shape. Mr Sterk is also developing the "brain" needed to control such a building based on information from internal and external sensors.
　　Cars are already capable of monitoring their own performance and acting with a certain degree of autonomy, from cruisecontrol systems to airbag sensors. Such responsive behaviour is considered normal for a car; architects argue that the same sort of ideas should be incorporated into buildings, too.
　　And just as the performance of a car can be simulated in advance to choose the best design for a range of driving conditions, the same should be done for buildings, argues Gian Carlo Magnoli, an architect and the co director of the Kinetic Design Group at the Massachusetts Institute of Technology. He is devising blueprints for responsive houses. "We need to evolve designs for the best performing responsive building models," he says.
　　So will we end up with cities of skyscrapers that wave in the breeze? It sounds crazy. But, says Mr Sterk, many ideas that were once considered crazy are now commonplace. "Electricity was a batty idea, but now it's universal," he says. The same was true of suspension bridges and elevators. Dynamic, intelligent, adaptable buildings are "the logical next step", he claims.

　　如果建筑师能建造活的居住体系，而不仅是静止不动的建筑物，世界将会变成什么样子？这种居住体系拥有动态结构，能按环境变化更改外部与内部形态。这个引人争议的想法在建筑界掀起了不小的波澜。设想一下这样的房子，冬天能收缩，减少表面积与体积，以节约供暖成本；夏天能把自己遮盖起来，避免日晒；下雪后能把积雪抖落屋顶；飓风季节摩天大楼能作轻微摇晃，改变其空气动力形态，以分散增加的压力；办公楼则能够重新装配，以加强通风。
　　建造这样有反应的建筑物有赖于两种技术，一是能决定做什么的控制系统，二是能按要求改变建筑物形态的构件。建筑师们努力发展前者已经好多年了，但后者却要相对落后许多。
　　研发可变形构件的研究人员采取的途径之一是模仿自然。许多天然结构是无一定尺寸限制结构体系，比如蜘蛛网与细胞膜，这种由许多相联单元组成的结构相当牢固，能够随意改变形状，各单元却不会失去自己的结构完整性。这种结构能弯折扭曲，但构成结构的单元却不发生变化，那是生命的构造。Robert Skelton说，他在圣地亚哥的加州大学结构体系与控制实验室工作。
　　当Skelton还在努力求解无尺寸限制结构体系的工程学方程式时，Tristan d'Estrée Sterk已开始用这种结构的原理搭建可变形的建筑物骨架的原型了，斯德克服务于一家建筑公司的自动结构媒介与可反应建筑研究所，地处加拿大的温哥华。这个原型的轻型骨架是由金属杆与金属线组成的，由汽动装置控制，用它来作建筑物的墙壁，调整骨架布置就可以改变建筑物外形。Sterk先生还在研发控制建筑物的大脑，它能根据建筑物内、外部的传感器采集的信息作出相应决定。
　　汽车已经能监察自身状况并相应的作出一定程度的自动行为，比如行车控制系统与安全气囊感知设备。大家对汽车的有反应行为都已习以为常，而建筑师们认为类似的功能也应被整合进建筑物。
　　而且在设计汽车时，设计师会根据不同驾驶情况模拟出汽车的表现，以选择最适合的设计方案，建筑师Gian Carlo Magnoli认为设计建筑物时也应当这样做，他还是麻省理工学院Kinetic设计集团的联席总监。Magnoli正为有反应的房子设计蓝图。他说，要设计出最出色的有反应建筑，我们的设计方式也需要进化。
　　那么将来会出现满城在微风中轻摆的摩天大楼吗？听起来很疯狂是吗？不过Sterk说，以前大家觉得很疯狂的许多想法现在却变成司空见惯的事。比如，以前大家觉得用电是个很古怪的想法，但现在电无处不在。相同的例子还有悬索桥与电梯。Sterk称：能灵活适应环境变化的智能型动态建筑是建筑业发展的下一个合理目标。