何为空间的句法？作为界面的建筑及其设计

作者： John Peponis

John Peponis，佐治亚理大学建筑学院教授，希腊注册建筑师，Kokkinou 与Kourkoulas建筑师事务所合作建筑师。

序言：空间句法和界面概念

人们通常认为空间具有双重性。我们将空间看作无限延伸或物体存在的场所。在日常生活中，我们认定空间本质上具有同质性：在温度等其他条件相同的情况下，物体在任何两地的形状和大小相同。然而除此之外，我们会从关系层面来理解空间。空间中的任何事物与其他事物可能存在远近、相邻、前后、上下、外部、表面或旁边等位置关系。通过设置边界，可将空间进行细分或重新连接。事物可位于其它事物或分隔结构的内部、之间、对面或外部。波特兰•罗素（1897）在其最早期有关几何学基础的著作中指出，空白空间（可能存在的关系）和空间顺序（物体存在时产生的实际关系）两者间存在明显不同。由于物体、边界或表面的存在，空间的延伸无时不刻不受限制。因此，栖居空间具有句法，即从空间中的某个位置看到或进入另一个位置的特定方式。“空间句法”是一种有关栖居空间在物理和社会层面的认知与理解的描述性理论，它关注空间环境在感知、 关联和功能等方面的可供性。这一定义考虑了空间句法学说的演化。最初，空间句法被定义为研究不同社会和文化的建筑空间基本组织原则的理论（Hillier, Leaman, Stansall and Bedford, 1976）。其后，为说明其对社会表现的影响，空间句法又被用作比较分析建筑空间的定量分析方法（Hillier, Hanson, Peponis, et al., 1983）。在《空间的社会逻辑》（Hillier and Hanson, 1984）一书中，作者对上述两种观点进行了综合，并指出：定量分析抓住了生成建筑空间的组织原则可被观测到的效果。

我对“空间句法”的定义侧重于空间关系的表述，它界定了空间句法的方法特点：线网模型（Peponis, Wineman, Bafna et al., 1998; Turner, Penn, Hillier, 2005）、不同类型的凸空间分割（Peponis, Wineman, Rashid, et al.， 1997）、视域多边形(Benedikt, 1979; Batty, 2001)，视域关系（Turner, Doxa, O’Sullivan et al.,2001）。这些基于空间关系的基本表述定义出一系列句法的度量方法，包括邻近度中心性或曰整合度、中介度中心性或曰选择度和触及度。不论是根据方向变化（Hillier and Hanson, 1984; Peponis, Bafna, Zhang, 2008）、边界穿越（Hillier and Hanson, 1984; Peponis, Wineman, Rashid, et al. 1997）、路径的角度变化（Turner,2007）或公（米）制的路径长度计算距离，上述方法均适用。空间句法的表述和度量方法描述了空间的结构，而空间结构界定了（人在空间中）可能的运动、进入、可视、共同在场或相遇（机会）。

“空间句法”一词暗示了空间的可供性，正是因为这种可供性，空间就像一种语言，一种我们可以通过设计空间关系来满足社会或个人生活方式的媒介。将组构定义为考虑其他关系的关系（Hillier, 1996; Peponis, Bafna, Dahabreh et al., 2015），强调了个体空间关系之间以模式化的方式相互作用、彼此支撑。例如：两个房间之间的关系可以是不对称的（如果需要先穿过一个房间，方能到达另一个房间），也可以是对称的（如果从房间外部可独立地到达任何一个房间）（Hillier, 1996）。空间句法的度量方法抓住了模式的结构特征，当中的每一种关系都可能受到其他关系的影响。根本的要点在于，建筑空间的人文功能建立在这一强烈和可被理解的关联性基础上。

我们现在对作为空间语言理论的空间句法和它的用途做个区分；二者分别关于社会空间系统的理解和设计。有哪些概念能够帮助我们理解空间句法语言陈述的观点？我用“界面”的概念来回应这个问题。

希列尔和汉森（1984）曾在两个语境中使用“界面”一词。在分析聚落时，他们用界面描述系统中开放和封闭部分之间的关系。“界面图”表示每幢独立建筑与该建筑连接的公共可达的凸空间单元之间的联系，以及凸空间之间相互连接形成的供出行和共同在场的连续空间系统。界面图暗示了居民与陌生人之间的关系：即有权进入或拥有至少一幢建筑的人员与仅能进入公共开放空间的人员之间的关系。

希列尔和汉森亦提出，建筑的内部结构形成了不同类型的使用者之间的界面，最明显的是“住户”和“访客”。住户指有权拥有和使用建筑各项功能的居住者，而访客是指获住户许可方能访问建筑的用户。其次，住户与访客之间的界面还被描述为两类用户所分别享有的建筑各部分的句法属性，和两类用户相遇空间的属性。在该情形中，将建筑划分为分布式和非分布式子系统就显得尤为重要。分布式系统包含了可利用流线中的环路经由其他路径到达的空间。非分布式子系统包含了从分布式系统分支出去的只能按照流线序列顺次到达的空间。研究表明，在很多类型建筑中，住户与访客之间的界面反映为分布式与非分布式子系统之间的区分与联系。

分析表明，社会范畴的空间定义建立在不同句法条件的内在特性基础上。创建不同条件并建立相互关联，是建筑学的基本目的之一。因此，我们可从如下角度思考界面：界面形成于某种模式下不同的句法条件或可供性的系统性创造和关联。虽然不同的句法条件和社会类别之间的联系可能是空间的社会逻辑的根本，但我认为这并非界面的本质所在。

最近的学界讨论结果与一般意义上的界面定义相契合。希列尔（2001）曾提出，大多数城市可以区分出两个子系统：即主要街道网络（将城市连为一体的整体网络）和分布在主要街区中的普通街道形成的局部网络。一条主要街道通过广角相交方式与其他主要街道相连，提供了更长的线性运动或视野；而局部街道提供了较短线性运动和视野，它们之间通常以直角方式相交，虽然提供了多种路径选择，但这些路径在运动和视线的方向上几近相同。从本质上看，希列尔将街道网格看作局部和整体两种组织规模之间的界面。我本人也提出过类似的观点，建筑物能被读懂是基于主要空间和一般空间的系统性设置所形成的界面；主要空间指具有扩展视野和多方向连接的全景空间，一般空间指感知能力被限定在室内特定范围内的空间（Peponis, 2012）。走廊、庭院、中庭和大厅是我们可能用来设置界面的措施。

以下章节从研究、设计实践和工作坊教学的角度展开有关界面例子的讨论。

互动与合作的界面和机构生产力： Thoughtform Inc.（匹兹堡）

ThoughtForm Inc. 是一家位于匹兹堡的传播设计公司，其办公场所由Archideas事务所的Michael Fazio于2002年设计建造。该项目旨在加强内部合作、促进员工互动、提高创造力和生产力。项目利用了Steelcase公司愿意提供定制办公设备的机会。2005年，Steelcase与佐治亚理工学院的空间句法研究团队协作，共同对设计的有效性进行研究，并发表了相关的研究报告（Peponis、Bafna、Bajaj等，2007年）。与该公司老的办公场所相比，新办公场所更有助于员工在项目构思和概念发展阶段提高工作的效率和效果。

办公楼平面为矩形，长宽为20 x 74米，占地面积约1,500平方米。主要通道为贯穿整个办公区楼面长度的双边开放式走廊。沿办公楼的长边边缘另设有通道连接各工作区。从入口大厅走进，迎面而来的是多功能开放式公共休息室，可用于举办正式和非正式会议或咖啡休息。紧挨着休息室的是四间项目室，是项目团队的大本营。由于采用折叠墙隔板设计，项目室可向休息室关闭或开放。主通道的两端分别设有小型的封闭式会议室。图书室内设有额外座椅，供员工休息使用。员工工作区仅占楼面面积的50%，大幅低于老办场所的70%（图1）。

我们进行研究时，ThoughtForm Inc.拥有约50名员工。问卷调查表明，员工十分满意工作场所的布局，在需要时有场所可召开会议及展开团队工作。社会学计量分析表明，在每名员工与公司余下65%的员工保持互动的情况下，员工之间的整体接触密度不会发生大的变化。然而，员工每天或每周在工作间隙发生互动的频率和比例增加。频繁的接触在整个办公室内形成一个关系网络，使得大多数员工不仅与工位附近的同事产生互动，同时也与其他同事产生互动（图1.4）。此外，新办公楼内工作区的中心性和与其所对应的互动网络中员工的中心性之间的相关度大大增加。因此，就空间布局而言，员工的互动模式变得更加明显易懂。

新工作场所的设计增强了员工的共同意识，这是项目构思和概念发展效率提升的原因所在。例如，面对面交流的比例提高，意味着当中一人或两人需穿过中间休息室和邻近项目室。因此，多数互动，不论其目的和初衷，都意外地增加了寻求和提供建议、专业知识或其他贡献的可能性。新的布局以非正式的方式加深了员工对组织运作的了解，从而提升了创造性和生产力。

我希望探讨界面设置对非正式学习的影响，这对知识型工作而言至关重要。第一个、也是最显而易见的界面是实际或潜在的走动或互动。希列尔和佩恩（1991年）已经注意到该界面的重要性。Thoughtform的所有会议室均与主通道相连或被其贯穿。此外，每个工作团队所在的工作区均配有移动式卫星资源中转设备，可邀请其他同事召开简短会议。这件定制的家具配有书架，可存放从主图书室借阅、或由团队成员整合或编制的项目关键文件。这件家具的顶部高度不超过手肘高度，员工可将其用作资料阅读桌、咖啡或笔记本摆放桌。所有中转设备均摆放在主通道视线可及之处，其中半数以上紧挨着主通道。可以说，空间布局对互动的支持无处不在。（图1.5）。

第二个界面普遍存在于员工走动和可视化信息之间。点子、草图、图片或便签、海报和便利贴的痕迹虽然随处可见，但并非办公场所内的所有位置都能轻易看见。办公室内配备软质黑板和标记板，供会议室、团队工作区和个人工作位使用。新办公场所还留有题写会议主题词的空间，供会议召开时使用。

第二个普遍存在的界面位于运动和视觉信息显示之间。点子、草图、图片或便签、海报和便利贴的痕迹虽然随处可见，但并非办公场所内的所有位置都能看清楚内容。办公室内配备软质黑板和标记板，供会议室、团队工作区和个人工位使用。新办公场所还留有题写会议主题词的空间，供会议召开时使用。

上述两个界面的存在，使每名员工与其他员工得以维持一种动态关系，而不论其是否身处同一项目组，也不论其是否有着类似的专业知识背景和经验。办公室的人际网络无形中扮演着共有知识的集体管理者和生产者的角色。然而，空间内的相遇和视觉交流成为人际网络有效运作的媒介。

在此案例中，界面设计并非单纯设计一条笔直穿过办公场所的中心走道，该办公场所中走道与楼层边缘的距离最多不超过10米。界面设计涉及其他方面，包括集体办公区内工位的设置，会议区的预留，以及定制化家具和设备的陈列。若用空间句法语言，则可将其概述为引导目标对象沿清晰的整合中心运动，而该中心总体上具备知识型工作所需的互动、学习和协作功能。将布局、家具和设备设计作为机构及其文化的整体部分，是句法的整合度能发挥积极作用的原因所在。

机构的个性和功能可供性：雅典比雷艾夫斯街贝纳基博物馆

2001年，Maria Kokkinou和Andreas Kourkoulas两位建筑师被选中负责设计位于雅典比雷艾夫斯大街138号的贝纳基博物馆新馆。两位建筑师都曾在伦敦向比尔•希列尔求学。在该项目中我担任两位建筑师的设计顾问。比雷艾夫斯大街的两端分别连接着雅典老城和比雷艾夫斯港，街道沿着雅典长墙的北墙延伸。长墙是公元前5世纪保护雅典城和比雷埃夫斯港之间通道的重要工事。自19世纪起，比雷艾夫斯大街沿线主要为工业区和低收入住宅区。最近数十年间，逐步的城市更新改造为比雷艾夫斯大街重新赋予了文化生活功能。2004年建成的贝纳基博物馆新馆是更新改造过程中的里程碑项目。

自1929年建成至今，贝纳基博物馆的永久馆藏一直以希腊文化藏品，横跨古希腊、拜占庭帝国和现代希腊等多个时期。博物馆的老馆位于雅典城中心的宪法广场附近。新馆位于比雷艾夫斯大街，计划作为博物馆的卫星式分馆使用，举办临时性委托、策划或巡回作品展。新馆原为一处庭院式布局的汽车修理厂房，经改造和扩建后建成。入口设置在侧面的小街上，充分利用了建筑后退红线较大的优势。

新馆在设计时保留了庭院，以其为博物馆的核心，并且保留了从侧面小街进出的入口方式以控制比雷艾夫斯大街噪音和车流的影响。新馆处于两个风格截然不同的边界包围之中：外墙面为红色石墙，仅策略性设有几个条形窗。庭院内立面中的三面为软质表面，实为向上倾斜的巨型“屏风”。屏风由特别设计的水平百叶组成，百叶的材料为大绿柄桑木，角度可调，用来控制阳光入射。新馆上面的三层在 “屏风”与建筑内边之间设有通廊。外挑的通廊和“屏风”在底层沿庭院周边形成光影。庭院内立面的第四面与入口相对，由夹在内墙和金属框架玻璃幕墙之间的之字形坡道形成。坡道用于展现参观者的行走轨迹，是博物馆的一大特色。虽然坡道使主要立面的形象鲜活，但“屏风”暗示了其他三个立面后潜藏的风景。底层庭院由鹅卵石铺就，畅通无阻。站在比雷艾夫斯大街，可以从外墙的条形窗、博物馆前部的商店和咖啡厅窥见馆内的景象。大尺度的空间开敞使得庭院得以向后延伸至博物馆展览区。因此，尽管以坡道为主精心设计的正立面形象主导了入口方向的轴线景观，但横轴上空间的层叠展示了与之不同的富有变化的景象（图2）。

Angelos Delivorias和Irini Geroulanou先后担任贝纳基博物馆馆长。Angelos Delivorias于2014年离任，此后，由Irini Geroulanou负责新馆的修建和运营工作。在两位富有创见的馆长领导下，博物馆发展成为雅典的文化地标。博物馆被视为不同艺术和文化社群的集会地和放大器，以及积极参与艺术公众化的机构（Delivorias,2004）。庭院对博物馆实现这一创想发挥了极其重要的作用。庭院中不仅举办装置作品展、雕塑展，而且还举办各类音乐和戏剧表演、社交和集会活动。庭院在举办文化活动时所受的欢迎程度及其功能的多样性超出了设计团队和馆方的预期。在设计过程中，客户及其顾问曾一度提议将庭院改为绿化。在主体建筑完成后，设计团队在实施馆长的构想过程中发现，可以将庭院设计为独具特色的多功能舞台。简言之，庭院设计提供了丰富的功能，有助于发展、丰富和厘清馆方最初的用意（图3）。

下列设计举措强化了庭院作为舞台的特点。首先，尽管博物馆底层的视线联系较广，将博物馆入口置于侧面小街则从认知和情感上切断了庭院与比雷艾夫斯大街的联系。其次是庭院立面材料的质感与区分。第三，庭院四周的围护结构暗示着场馆内其他人的出现。身处博物馆之中，参观者可体会到相互之间的看与被看、打招呼与被打招呼。第四，正对入口轴线看到的参观者在坡道上的行进如同庭院与博物馆之间形成的舞台上的前景运动，与比雷艾夫斯大街上的人车流呈直角关系。第五，倾斜的“屏风”拓宽了纵向视野，将整个庭院的风光尽收眼底。在贝纳基博物馆，视觉形态起到强化空间的组织和活力的意象。庭院的空间感觉吸引着参观者探索潜在的可供性和空间关系的在场体验，并强调了对于栖居的渴望。

本质上，设计确定了一种组构方式，通过可达与可见、运动的连续性与视线能否穿越渗透性或透明性边界之间富有表现力的界面，调和了外部街道与内部庭院、内部庭院与建筑之间的双重功能性关系。知觉空间的结构与入口、流线序列的精心层叠，使得各种可能的功能在庭院内被不断发现和实施。通过这一方式，建筑为机构赋予了部分的个性特征。

建筑类型的转变：亚特兰大佐治亚理工大学，零售业的未来设计工作坊

零售业正面临着重组以便应对科技、经济和文化的发展变化。高效可靠的线上卖家和物流服务的出现，令人质疑实体商店是否有必要存在。专家主张推行集实体店、网上购物及移动应用程序购物于一体的全渠道零售，使顾客能随时随地、随心所欲地购买商品。我们正面临Mitchell在1999年描述的空间和文化体验上的深刻变化。在2017年春获得NCR的研究资助后，我主持了一项本科生参加的设计工作坊，探索除便利性外，逛商店对消费者来说还有哪些重要的可取之处。服务模式不给力的实体零售店受线上卖家的冲击最为明显。因此，我们想知道什么才是实体零售店需重新定义的固有功能。

商店有助于消费者发现新事物。当我们在书店无意间发现一本感兴趣的新书时，或在超市找到一款新口味奶酪时，我们对该商店供货范围的认知得到扩充。因此，商店不仅仅是直接搜索特定商品的场所，还是开放式搜索的场所。开放式搜索有助于新产品和新想法的传播。

商店有教育功能。例如，在乐器店，顾客可以直接感受外形相似的乐器之间的细微区别。传统屠夫会根据顾客的烹饪需求向其推荐肉品。药剂师会对轻伤治疗提供意见。商店的存在，为一般性需求与特定实用技术的对接提供了可能。同时，商店有助于我们明确购买商品的想法、习惯和行为。随着我们越来越关注与健康、环境和社会生产条件有关的各种产品之间的关系，商店的教育功能将越来越重要。

信誉是商店兴旺的基础。这对提供定制化服务的商店，如裁缝店，或提供个性化建议的商店，如专业书店而言，尤其重要。店主或店员可扮演专家和顾问的角色。

商店的某些附属功能同样重要。商店提供了偶遇的场所，犹如一间社会剧场，人们之间互相看与被看。在发展视觉传播语言方面，商店和博物馆的作用同等重要；在物质文化的传播方面，商店的作用更大。即便未能达成交易，顾客和商店品牌之间的心理联系也会得到加强。

工作坊以团队形式开展工作。两个小组针对商品陈列、存储和客服之间的界面重组，以相似的方式发展了不同的组合，旨在解决大多数百货商店普遍存在的功能混乱问题。

Collin Garnett、Tim Peterson和 Christina Delurgio组成的小组沿着基地的两个主要边界设计了细长的L形展廊式空间，用于商品陈列。L形陈列空间限定的范围内，设计了相互连接的三维矩阵式吊舱，作为导购员和顾客的交流区。吊舱设计为创意空间，顾客与店员在这里交流，根据交流的结果对某家公司的产品或某种产品进行定制化、修改、组合或开发。吊舱式空间位于底层公共开放空间之上，既可充当举办各类表演和活动的通道和独立的公共场所，也可以借助周围的咖啡厅、酒吧和餐厅体验日常城市生活。货物储存于地下室，由电梯送至吊舱式空间（图4）。

Danny Griffin、Maria Pastorelli和Skylar Royal小组设计了画廊式商品展示区，沿商场正前方非对称布局的公共空间逐层向上分布。小组成员对展廊空间进行了仔细研究，可以让顾客在其中使用移动设备订购商品。在底层，两侧的小型商铺丰富了公共空间的内容。在上层空间，商品展廊后方设有货物存放区，用于存放和配送货物。货物存放区和商品展示区之间设有厚墙容纳商品自动传送。在顶层，顾客手拎装有选购产品的购物篮，对产品进行试穿，并与专业的员工讨论组合搭配、定制或改进。为向顾客提供方便，顶层设有试衣间/咨询室、配有酒吧的大厅，顾客可在此一览城市美景。有通道可通往位于货物存放区上方的创意工坊车间和实验室（图5）。

通过对百货商店的界面进行重组，两支设计团队从三个维度建立了视觉联系，加强了看与被看见之间的关系，强化了商场的社交场合感。构成商店前景的商品展示和客商交流充分利用了商品存储和检索的新技术、同时也支持客户将选中商品放入虚拟购物篮内。

两个设计方案的表现成果包括建筑表现图、展示主要界面定义与组成的轴测分解图、和描述购物体验序列的故事板。这些图阐述了界定建筑类型的界面重构所涉及的几何、动线、视线和功能概念。上述项目仅代表了商业建筑类型演化的一种可能性路线，而决非定论。然而，相关的设计成果表明，创造某种可能性的抽象空间设计与形成启发式的界面概念之间存在密切关系。

界面的定义

在上述三例中，界面与空间关系存在联系，界面或存在于子系统之间而非单个要素之间，或在某种模式之中不断重复：在Thoughtform表现为员工互动与交通流线的关系；在贝纳基博物馆表现为庭院内部及其周边空间的可见与可达关系；在学生设计工作坊项目表现为商品陈列、存放和商客互动区之间的关系。因此，界面涉及多类元素。界面的言外之意暗示了某种概念化，即根据某种共性将某些元素归为一类。上述三个案例的共同之处是提供了某些可供性，这些可供性在功能上的重要意义与某种特定的句法条件相关。

我本人对界面提出如下定义：界面指影响整体空间结构的各类要素之间的复合关系。功能的可供性及其相关的句法条件界定了要素的类别。组构的概念指一组关系基于所有其他关系的影响，界面的概念则要求关系分类的有序组织。系统的组构属性是形成界面的素材。与此同时，界面表述了更高层级的布局原则，不论这些原则来自常识，或源于对设计意图的反思。

界面的种类多种多样，如社交互动界面、功能分区界面等。贝纳基博物馆案例的意义重大，它表明知觉模式与运动可供性之间的界面在特定环境中具有潜在功能发生器的重要意义。

任何特定的设计或某种类型的设计，界面都非常重要，它是建筑类型、功能意图、设计构思和概念形成的产物。然而，空间句法理论表明，只有当什么是重要界面的开放，构建界面的几何形式开放，才可能有本文定义的界面理论。正如文中引用的希列尔（2002年）和佩恩（2012年）的著作所述，建筑空间中最根本的界面在于局部和整体两种尺度关系的组织。这是空间能够被从人和文化的角度理解的根本所在。

界面基本理论的发展，特定类型或功能模式的界面模型的发展，丰富了关于空间的社会与文化逻辑的解释性理论及其规范化命题的发展。界面的概念也架起了空间句法理论与设计意图或设计构想之间桥梁。

鸣谢

在本文的写作过程中与比尔•希列尔的交流让我受益匪浅。他发表的观点毫无疑问是本文讨论的核心所在，他的意见让本文的观点得以成形。

Introduction: Space Syntax and the idea of interface

Our common understanding of space is dual. We understand space as pure extension or volume in which things exist. In everyday life, we assume it to be homogeneous in fundamental ways: material objects will have the same shape and dimensions in any two locations, other things, such as temperature,being equal. In addition, however, we understand space in terms of relationships. Things in space are distant, proximate or adjacent, in front, behind, above,below, beneath, beyond, on, under, or beside other things. Space can be subdivided and reconnected by an arrangement of boundaries. Things can be inside,between, across, or outside relative to other things or enclosures. In his earliest work on the foundations of geometry, Bertrand Russell (1897) drew a distinction between empty space as the possibility of relations and the order of space, the actual relationships that arise when material things are present. With the presence of objects, boundaries or surfaces, extension is never unrestricted. Hence, inhabited built space has a syntax,a particular way in which one location can come into view or be accessed starting from another.

‘Space syntax’ is a descriptive theory of the perceptual, relational and functional affordances of inhabited space that are relevant to its cognitive and social intelligibility. This definition takes into account the evolution of the field. Originally, space syntax was proposed as the theory of the fundamental organizing principles that govern built space across societies and cultures (Hillier, Leaman, Stansall and Bedford, 1976).Subsequently space syntax was introduced as a set of quantitative techniques applied to the comparative analysis of built space (Hillier, Hanson, Peponis, et al.,1983) in order to account for its social performance.In the Social Logic of Space (Hillier and Hanson, 1984)those two ideas were brought into a unified argument:quantitative analysis captures the observable effects of the principles of organization that generate built space.

The definition I offer puts the emphasis on the representations of spatial relationships that define space syntax methods: line-maps (Peponis, Wineman,Bafna et al., 1998; Turner, Penn, Hillier, 2005), various kinds of convex partitions (Peponis, Wineman, Rashid,et al. 1997), visibility polygons (Benedikt, 1979; Batty,2001), visibility relationships (Turner, Doxa, O’Sullivan et al., 2001). Syntactic measures, including closeness centrality or integration, betweenness centrality or choice and reach, are defined on the basis of such underlying representations of spatial relationships. This is true whether distances are calculated according to direction changes (Hillier and Hanson, 1984; Peponis, Bafna,Zhang, 2008), boundaries traversed, (Hillier and Hanson,1984; Peponis, Wineman, Rashid, et al. 1997), path angular rotation (Turner, 2007) or metric path length. The representations and measures of space syntax describe the structures of space that define possible movement,access, view, co-presence or encounter.

The term ‘space syntax’ alludes to the fact that by virtue of such affordances, space acts like a language,a medium in which we can design relationships to accommodate desirable ways of common or individual life. The definition of configuration as relationships that take into account other relationships (Hillier, 1996;Peponis, Bafna, Dahabreh et al., 2015) underscores the fact that individual spatial relationships interact with and qualify each other in the context of patterns. For example, the same connection between two rooms can be asymmetric, if access to one room depends upon first traversing the other; or it can be symmetric,if each room can be independently accessed from the outside (Hillier, 1996). The measures of space syntax capture the structural properties of patterns wherein each relation is potentially affected by all others. The fundamental thesis is that the human functions of built space are built on this foundation of intense and intelligible relationality.

We can now distinguish between space syntax, as a theory of the language of space, and what space syntax is used for; namely to understand and design sociospatial systems. What are the concepts that may help us to understand the statements made in the language of space syntax? In response to this question I focus on the idea of interface.

Hillier and Hanson (1984) use the word ‘interface’in two contexts. In the analysis of settlements, they describe the relationship between the open and closed parts of the system. ‘Interface maps’ represent the connection between each discrete building and the publicly accessible convex space that the building is linked to, as well as the interconnections of convex spaces into a continuous system of movement and copresence. By implication, interface maps capture the relationship between inhabitants and strangers: the people that have rights of access to, or ownership of,at least one of the buildings and the people that only have rights of access to the common open space.

Hillier and Hanson also propose that the internal structure of buildings constructs interfaces between different categories of users, most notably between‘inhabitants’ and ‘visitors’. Inhabitants are the occupants who have authority and power over the functions of the building and visitors are the users whose access to the building is subject to regulation by the inhabitants. The interface between inhabitants and visitors is then described in terms of syntactic properties of the parts of the building that are severally available to each category of users and the properties of the spaces in which the two categories meet. In this context,the partition of buildings into distributed and nondistributed subsystems acquires particular significance.The distributed system comprises the spaces that can be reached in alternative ways taking advantage of the presence of circulation loops. The non-distributed subsystem comprises the spaces that can only be reached by circulation sequences branching off the distributed system. It is suggested that in many kinds of buildings the interface between inhabitants and visitors is mapped onto the distinction and relationship between the distributed and non-distributed subsystems.

The analysis shows that the spatial definition of social categories is built upon the intrinsic properties of distinct syntactic conditions. The creation and interrelation of distinct conditions is a fundamental purpose of architecture. We may, therefore, think of the idea of interface as follows: An interface exists when distinct syntactic conditions or affordances are systematically created and related within a pattern.The association between distinct syntactic conditions and social categories may be fundamental to the social logic of space but it is not, I suggest, intrinsic to the idea of interface itself.

More recent arguments fit within the generalized idea of interface. Hillier (2001) has proposed that in most cities a clear distinction can be drawn between two subsystems: the primary streets which form a global network that connects the city as a whole; and the local networks of ordinary streets in the areas between the primary streets. Primary streets afford longer straight lines of movement and sight extended by means of wide-angle intersections to other such lines. Local streets provide shorter straight lines of movement and sight and usually intersect at right angles offering choices between alternative but equivalent directions of movement and sight. In essence, Hillier looks at street grids as interfaces between two scales of organization,local and global. Similarly, I have suggested that buildings are intelligible based on the systematic creation of an interface between prominent spaces that provide an overview of extended areas and of multiple connections and normal spaces which confine perception to a limited part of the interior (Peponis,2012). Corridors, courtyards, atria and halls are devices that we use to make such interface possible.

In the following sections I discuss examples of interfaces from the perspectives of applied research,professional design and studio teaching.

Organizational productivity and the interfaces of interaction and collaboration: Thoughtform Inc.,Pittsburgh.

The workplace of ThoughtForm Inc., a communications design company located in Pittsburgh, was created by Michael Fazio, of Archideas, in 2002. The aim was to enhance internal collaboration and interaction and accelerate creativity and productivity. The project took advantage of the willingness of Steelcase to supplement catalogue office furniture with custom designed pieces. The effectiveness of the design was studied by Steelcase in 2005 in collaboration with the space-syntax research team at Georgia Tech and a report was published (Peponis, Bafna, Bajaj et al.,2007). The new premises allowed the ideation and concept development phases of projects to proceed more effectively and efficiently as compared to the old premises.

The layout occupies a rectangular office floor of about 20 x 74m and an area of about 1500m2. The main circulation is along a double loaded open corridor traversing the entire length of the floor. Alternative connections between work areas are made along the edge. Facing the entrance hall, a multi-purpose open lounge accommodates formal and informal meetings or coffee breaks. Adjacent to the lounge, four project rooms function as home bases for project teams.With folding partitions, these rooms can be closed or opened towards the lounge. Smaller enclosed meeting rooms are located at the two ends of the main circulation. Additional seating for relaxation is available in the library. Individual workstations cover only 50% of the floor, a drastic reduction compared to 70% in the old layout (FIGURE 1).

Questionnaires indicated that employees, who were about 50 at the time of the study, were very satisfied with the range of work settings that were available to them, and with the ability to have meetings and work in groups as needed. Sociometric analysis showed that the overall density of contacts between employees did not change much, with each employee interacting with about 65% of all other employees. However, the proportion of interaction that occurs more frequently at the daily or weekly time intervals increased. Frequent contacts form a network that covers the entire floor,with most individuals interacting not only with people in the vicinity of their workstation but also with people across the floor (FIGURE 1. 4). Furthermore, correlations between the centrality of workstations in the layout and the centrality of the corresponding individuals within the network of interaction increased dramatically in the new premises. Thus, the pattern of interaction became more intelligible in terms of the organization of the layout.

The explanation for the increase of effectiveness during project ideation and concept development resided in the way in which the design promoted co-awareness.For example, a great proportion of reported face-to-face interactions imply that one or both parties had to walk past the central lounge and adjacent project rooms.Thus, most interactions, regardless of their purpose and origination, increased the likelihood that advice,expertise, or other contributions could be sought and offered serendipitously. The layout enhanced creativity and productivity by supporting an almost ubiquitous process of informal learning about the functioning of the organization at any point in time.

I would like to discuss informal learning as a function of the way in which the layout organizes interfaces which are critical to knowledge work. The first and most obvious interface is between movement and interaction, actual or potential; the significance of this interface has been noted by Hillier and Penn (1991).At Thoughtform, all meeting rooms are linked to the main circulation or traversed by it. In addition, each cluster of workstations associated with a work team is equipped with a satellite resource hub on wheels which also invites brief meetings. This custom-designed piece of furniture provides shelves for storing documents critical to the project, whether borrowed from the main library, or assembled or produced by the team. The top surface is at elbow height to afford spreading material for review, or resting a cup of coffee or a notepad.Hubs are visible from the main circulation and more than half of them are immediately adjacent to it. Thus,interaction is supported across the layout (FIGUREE 1.5).

The second interface, as ubiquitous, is between movement and the display of visual information. Traces of ideas, diagrams, images or notes, posters and post-it notes are visible — but not necessarily readable — from almost any position. Pin-up and marker boards are designed to be carried between meeting rooms, team areas and individual stations. Surfaces of inscription are usually present wherever a brief or longer meeting can take place.

These two interfaces ensure that each individual employee sustains evolving relationships to many others, whether they working on the same project or not, whether they are endowed with similar expertise and experience or not. The network of people are the collective custodians and producers of shared knowledge. However, encounters and visual communication in space are the medium in which the network functions productively.In this example, the design of interfaces is not a simple matter of running a straight central corridor though a work environment with is never more than 10 m deep from the edge of the corridor to the perimeter of the building. Much else is involved, ranging from the arrangement of workstations into clustered group areas and the provision of meeting areas, to the presence of customized furniture and equipment. From the point of view of space syntax, one can summarize the condition as the channeling of movement along a legible integration core which is systematically invested with affordances for interaction, learning and collaborative knowledge work.The positive effects of syntactic integration result from the design of layout, furniture and equipment as integral parts of the organization and its culture.

Programmatic affordances and institutional identity:the Benaki Museum at Piraeus Street, Athens.

In 2001, Maria Kokkinou and Andreas Kourkoulas, both of whom had studied with Bill Hillier in London, were selected to design the new Benaki Museum at 138 Piraeus Street, in Athens. I worked as their architectural consultant. Piraeus Street is the historic link between Athens and the port of Piraeus. It traces the north wall of the Long Walls that defined and protected the connection in the 5th century BC. Since the 19th century, it has been associated with industry and lower income housing. In recent decades, a process of gradual transformation brings the street back into the cultural life of the city. The new Benaki Museum, completed in 2004, stands as a landmark of this process.

Since its creation in 1929, the Benaki Museum has been associated with its permanent collection of Greek culture, spanning from ancient through byzantine to the present; this is on display in a historic building at the center of Athens, near Syntagma Square. The new premises at Piraeus Street were programmed as a satellite museum that would host temporary exhibitions, whether commissioned, curated or travelling. The building was designed as a conversion and extension of pre-existing industrial structures arranged around a courtyard and mostly used for car repairs. Access was provided from a side street, taking advantage of a wide set back.

The design retained the courtyard as the fulcrum of the museum, and preserved access from the side street to control for noise and traffic on Piraeus Street. The new building is contained between two radically different boundaries: The external hard face is covered in red stone and is only pierced by a few strategically placed strip windows. The internal soft face, around three sides of the courtyard, is defined by an upwardly slanted screen, composed of custom designed horizontal iroko wood louvers that rotate to regulate incident sunlight. Access balconies run between the screen and the edge of the building on all three upper floors. On the ground floor, the projecting balconies and screen cast a shade along the perimeter. The fourth side of the courtyard, across the entrance, is defined by a dogleg ramp ascending between an inner wall and an outer glass face protected by a steel mesh. The ramp is intended to showcase the movement of visitors as an essential feature of the museum. While the ramp animates the dominant internal elevation, the screen implies potential presence along the other faces. The floor of the courtyard is completely unobstructed and covered in cobblestones. From Piraeus Street, the inner space can be glimpsed from the strip window, through the museum shop and café at the front of the building.Large openings allow the extension of the courtyard plane into the exhibition space at the back. Thus, while the dominant impression along the entrance axis is one of deliberate frontality dominated by the ramp, the cross axis suggests variable potential views through layers of space (FIGURE 2).

The museum has become a cultural landmark in Athens as a result of the innovative vision of Angelos Delivorias, who directed it until 2014, and Irini Geroulanou who has was in charge of the creation and operation of the building at Piraeus street. The museum was conceived as a meeting point and an amplifier of diverse communities of art and culture,an institution that actively engages the formation of its public (Delivorias, 2004). As part of this vision, the courtyard played a particularly significant role. It has hosted not only installations and sculpture exhibitions,but also all kinds of music and theatrical performances,events and gatherings. The popularity and flexibility of the courtyard as a cultural venue exceeded the expectations of the design team and the client organization alike. At some point in the design process,the client and some of their consultants advocated that the courtyard be turned into a planted green oasis.The idea that the courtyard could function as a flexible stage of unique character was discovered in the process of implementation of the general curatorial vision,after the building was finished. In short, the design of the courtyard provided rich affordances that helped develop, enrich and clarify the original programmatic intentions of the administration (FIGURE 3).

The following design moves contribute to the character of the courtyard as a stage. First, the cognitive and affective separation from Piraeus Street, achieved by offsetting access even as visual links are abundant on the ground floor. Second, the distinct material feel of the courtyard. Third, the fact that the building envelop around the courtyard implies and reveals human presence; visitors become aware of the reciprocity of seeing and being seen, addressing others and being addressed by others, in all of its parts. Fourth, the frontal foregrounding of movement as proscenium between courtyard and building along the axis of entry,at right angles to the traffic on Piraeus Street. Fifth, the slanted screen that pushes views upward and brings the whole volume into the purview of visual attention.At the Benaki museum visual form functions as an image of the organization and animation of space. The spatial feel of the courtyard invites the exploration of latent affordances and the embodied experience of spatial relationships; it foregrounds a desire to inhabit.

In essence, the design establishes a configuration where the double instrumental relations between street exterior and courtyard interior as well as courtyard and building interior are mediated by expressive interfaces between access and view, the continuity of movement and the ability to look across permeable or transparent boundaries. The structures of perceptual space that are deliberately overlaid upon the sequence of entry and access generate the great variety of programmatic possibilities that are continuously being discovered and enacted in the courtyard. In this way, architecture becomes part of the identity-in-action of the institution.

Transformations of a building type: a design studio on the future of retail, Georgia Tech, Atlanta.

Retail is being reorganized in response to changes in technology, economy and culture. The efficiency and reliability of web-based vendors and delivery services challenges the necessity for shops altogether. Experts argue for omni-channel retail: the integration of physical shops, web-pages and mobile applications so that customers can buy what, when and where they choose. We are dealing with a profound transformation of spatial and cultural experience of the sort that was described by Mitchell (1999). In the Spring of 2017,with funding and research-based inputs from NCR,I run an undergraduate studio, to explore what, in addition to convenience, can still be fundamental and desirable about visiting shops. The retailers that are most challenged by internet vendors are those that offer an impoverished model of service. Thus, we asked what are the intrinsic functions of shops that must be freshly reasserted.

Shops help us discover new things. When we find an unanticipated book on a subject of interest while browsing at a bookshop, or when we find a variety of cheese that we have not previously tasted in the supermarket, our sense of what is available expands.Thus, shops are domains not only of directed search,where the aim is to find what you came to buy, but also of open search. Open search helps put new products and ideas in circulation.

Shops educate. At the music shop, the subtle differences between seemingly similar musical instruments can be directly felt. The traditional butcher opines on the suitability of a meat cut to a cooking intention. A pharmacist advises regarding the treatment of minor injuries. Shops help bridge between generic needs and desires and specific practical knowhow. They help define what aspirations, habits and practices we buy-into as we purchase a product. As our sensitivities regarding the relationships of products to health, to environment and to the social conditions of production increase, so the educational function of shops may assume greater significance.

Shops thrive on relations of trust. This becomes evident with the customization of a product, as with tailoring,or the provision of personalized recommendations,as with the specialized bookshop. The shopkeeper or salesperson can be an expert and advisor.

Some incidental functions also matter. Shops can provide a sense of occasion, a social theater where we go to see and be seen by others. They can be as important as museums in getting us to develop our visual communication languages and more important as transmitters of material culture. Even when a purchase does not occur, the psychological connection to the shop brand is reinforced.

Studio participants worked in teams. Two of the teams developed different compositions in order to reorganize the interface between display, inventory storage and customer service in similar ways. The aim was to address the prevailing confusion and intermingling of these functions in most department stores.

Collin Garnett, Tim Peterson, and Christina Delurgio created a thin L-shaped gallery-like space for display along the two most prominent edges of the site. Social interaction occurs in an interlinked three-dimensional matrix of pods, within the volume defined by the display edge. The pods are designed as spaces of creation, in which the products of a given company or of a given kind are customized, altered, combined or developed according to the dialogue between the customer and store specialists. The pods are raised over an open public space at ground level. This provides access as well an independent public venue to host performances and events, or invite ordinary urban life, taking advantage of surrounding cafes, bars and restaurants. Inventory is stored underground and reaches the pods through service elevators (FIGURE 4).

Danny Griffin, Maria Pastorelli and Skylar Royal created a gallery-like zone of display, ascending over a public space scooped asymmetrically at the front of the building. As they peruse the galleries, customers are able to order products by hand-held devices. At the ground level, the public space is flanked by small shops that directly contribute to its life. On the upper floors,a storage zone behind the display galleries handles inventory and distribution. A poché wall between storage and display accommodates automatic product movement. At the top floor, customers pick up a basket that contains the products they selected. They try them on as well as discuss combinations, customization, or development with specialized staff. To support this process, the upper floor provides generous changing/consultation lounges as well as a large hall with bar,taking advantage of the spectacular views over the city. There are connections to the workshops and development laboratories of a creative studio situated over the storage zone (FIGURE 5).

In so re-ordering the department store interfaces, the design teams created visual links in three dimensions,intensifying relationships of seeing and being seen, and amplifying the sense of social occasion throughout the store. The foregrounding of display and interaction took advantage of new technologies for inventory storage and retrieval as well as of new technologies that allow customers to select products into a virtual basket.

The figures that describe the two projects bring together architectural presentation drawings, an exploded axonometric diagram that shows the definition and composition of the primary interfaces,and story boards that describe the sequences of customer experience. They point to the multiple kinds of conceptualization of geometry, movement, view and program that are involved with any intentional restructuring of the interfaces that define building types. The projects represent only one possible path for the evolution of store typology, and are, therefore,open to debate. However, the intellectual operations evident in the drawings suggest a close relationship between the creation of an abstract space of design possibility and the motivating conceptualization of the relevant interfaces.

A definition of interface

In all three examples the interfaces under consideration are associated with spatial relationships that either hold between sub-complexes, rather than individual elements, or are repeated within a pattern: relationships between spaces of interaction and movement at Thoughtform; the interplay between visibility and access in and around the Benaki courtyard; the relationship between display, storage and interaction areas in the studio projects. Thus, an interface involves classes of elements. By implication, the idea of interface implies conceptualization, the grouping of elements according to some common characteristic. In all cases the common characteristic is some affordance held to be programmatically important and associated with a syntactic condition.

I propose the following definition of interface: An interface is a complex relation between classes of elements that holds over a spatial configuration as a whole. The classes of elements are defined in terms of programmatic affordances and associated syntactic conditions. While the idea of configuration points to the effects of each relation on all others, the idea of interface requires that relations be ordered in classes. The configurational properties of the system are the material interfaces are made of. At the same, time interfaces express higher order principles of arrangement,whether these are embedded in common know-how or arise from reflexive design intentionality.

There are many different kinds of interface. For example, we have interfaces of interaction or interfaces of distinct functional zones. The example of the Benaki Museum is particularly poignant because it suggests that interfaces between perceptual patterns and movement affordances can, in particular contexts, assume significance as generators of programmatic potential.

The interfaces that are significant in any particular design, or family of designs,are a function of building type, programmatic intent, and design formulation and conceptualization. The theory of space syntax, however, suggests that while the universe of significant interfaces is open, and while the set of geometries by which interfaces are constructed is also open, a theory of interface, as defined here, is possible. Based on the cited work of Hillier (2002) and Peponis (2012), the fundamental interface in all built space is the interface between local and global scales of organization. This is at the root of the human and cultural intelligibility of space.

The development of the fundamental theory of interface and of type or programspecific models of interfaces enriches our specific explanatory theories and normative theses regarding the social and cultural logic of space. The idea of interface also bridges between the theory of space syntax and design intentionality or design formulation.

Acknowledgment

In the course of writing multiple drafts of this article I have benefited from an ongoing conversation with Bill Hillier, whose published ideas are, of course, at the core of the arguments presented, and whose comments have helped shape them.

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Captions

Figure 1. Thougthform.

1.1: Thoughtform plan, 2005.

1.2: Lines analysis of all paths of movement. Syntactically central paths, which are more likely to attract movement, are shown in red.

1.3: Tiles analysis at knee level. The most directly accessible areas are shown in red.

1.4: Work related interaction network, daily time interval.

1.5: Areas programmed for holding formal or informal meetings.

(Plan by Archideas. All photographs and analytical drawings by the author.)

Figure 2. Benaki Museum, Piraeus Street.

2.1: Transverse section, facing towards the ramp.

2.2: Longitudinal section cut along the entrance axis.

2.3: Ground floor plan.

2.4: Southwest elevation showing the entrance.

2.5: Southeast elevation along Piraeus Street.

2.6: View of the courtyard from the south.

(Drawings by Kokkinou+Kourkoulas. Photograph by Erieta Attali.)

Figure 3. The courtyard of the Benaki Museum in use.

3.1: Sculpture installation, Thodoros, 2011.

3.2: Sculpture installation, Costas Varotsos, 2007.

3.3: Performance of the Oresteia by Iannis Xenakis, directed by Spyros Sakkas, 2005.

3.4: Performance of Antigone by Sophocles, directed by Natasa Triantafilli, 2013.

3.5: Large meeting held at the courtyard.

3.6: Gastronomy Days, a celebration of Greek cooking culture, 2013.

3.7: Landart, Antonis Pittas, 2013.

3.8: Exhibition, Costas Koulentianos, 2012.

(All photographs provided by the Museum.)

Figure 4. Store design proposal by Collin Garnett, Tim Peterson, and Christina Delurgio.

4.1: Approach from the urban plaza or the street.

4.2: Escalators and elevators take visitors up the display wall.

4.3: As they explore the displays, shoppers scan products with their phones and receive direction to pods.

4.4: The bridges to the pods offer spectacular views.

4.5: At the pod, shoppers consult with associates.

4.6: Associates summon products from the underground storage facility using a smart interface.

4.7: Shoppers test or try the products and discuss customization before purchase.

4.8: Purchases are completed using mobile POS systems.

Figure 5. Store design proposal by Danny Griffin, Maria Pastorelli, Skylar Royal

5.1: Approach to the urban plaza and street-level shops.

5.2: Escalators and elevators take visitors up through the display galleries.

5.3: As customers navigate the gallery, they digitally curate their selection.

5.4: While customers continue browsing, their selection is automatically retrieved from storage and collected into a personal pod.

5.5: At the top floor, customers enter lounges for comfortable and collaborative trial.

5.6: Personal pods arrive at the customer’s lounge via the delivery wall.

5.7: Lounges are linked to a large hall with views as well as a connection to the creative studios on the floor beneath.

5.8: Purchases are completed in the hall and automatically delivered to the customer on the ground floor.