關(guān)成賀 拉胡爾·梅赫羅特拉

1 簡介：低收入家庭和城市移民

來自貧困地區(qū)的人們通常會選擇搬到經(jīng)濟充滿活力的城市尋找就業(yè)機會。從20世紀初美國工業(yè)城市裝配線上的工人到20世紀末中國沿海城市大量的農(nóng)民工,城市移民們不僅被更高的工資所吸引,而且更加接近了很多不屬于他們的社會福利。然而，高密度城市中的城市移民往往會發(fā)現(xiàn)自己處于最不利的環(huán)境中[1]。為了改善城市貧困人口的基本生活條件，聯(lián)合國人居署提出了一系列的戰(zhàn)略。例如，提供可負擔的社會住宅，通過提供基本的公民服務來提升基礎(chǔ)設(shè)施（聯(lián)合國城市主題），并通過教育和培訓的方式來進行介入。實施這些計劃的挑戰(zhàn)在于，如何通過城市設(shè)計更好地促進經(jīng)濟可行性、社會公正和環(huán)境友好的戰(zhàn)略的達成。

本文的組織結(jié)構(gòu)如下：在第2節(jié)將對孟買的空間轉(zhuǎn)變歷程進行一個回溯。第3節(jié)將討論在孟買應用高層、中層、低層3種類型的城市設(shè)計介入策略來解決低收入移民和城市貧困家庭居住問題的區(qū)別。第4節(jié)將揭示連接不同類型“可負擔住宅”的空間邏輯，并提出一個面向高密度城市的更加可持續(xù)的混合反應設(shè)計策略。

2 孟買的城市空間轉(zhuǎn)變與城市設(shè)計介入

這篇文章所關(guān)注的孟買是一個貧民窟居民數(shù)量龐大且不同社會階層之間的土地使用權(quán)關(guān)系非常緊張的城市，這一切都為新型的居者有其屋（可負擔住宅）戰(zhàn)略帶來不小的挑戰(zhàn)。2016年，印度馬哈拉施特拉邦負責基礎(chǔ)設(shè)施建設(shè)的政府機構(gòu)—孟買大都會區(qū)發(fā)展管理局（MMRDA）提出了一個2036年的孟買區(qū)域規(guī)劃建設(shè)方案。在這個計劃中，孟買將建設(shè)新的城市中心、新的城市道路和一座新機場。如果實施，孟買的城市空間結(jié)構(gòu)將從單一中心轉(zhuǎn)變?yōu)槎嘀行?。因此，某些土地使用類型將被重新分配到城市的外圍。在此過程中，經(jīng)濟適用房（可負擔住宅）應該被仔細地考量并與其他城市功能有機結(jié)合。誰將被重新安置？哪些社會階層將繼續(xù)留在已經(jīng)過度擁擠的中心城市？這些問題都值得深思。

圖1展示了孟買低收入居住區(qū)的空間分布情況，預計有超過1,000多萬的人牽扯其中。許多機構(gòu)都試圖解決孟買大都市區(qū)的非正式住區(qū)、低收入住房和城市貧民窟的問題。我們將這些方式方法概括總結(jié)為3種城市設(shè)計干預的范式。

3 三種為低收入人群提供經(jīng)濟適用房的城市設(shè)計范式

對于城市貧民來說，并沒有一個普適性的解決方案。我們必須意識到每個項目都有其獨特性。我們將通過空間形態(tài)和建筑類型的維度來對它們進行分類。

3.1 高層建筑類型方法：城市升級

為了應對經(jīng)濟適用房的旺盛需求，一種方法是開發(fā)高層建筑，從而最大限度地提高住房供應量并達到更高的容積率。這一概念與20世紀設(shè)計先鋒們提出的著名方案沒有太大區(qū)別：增加緊湊型，最大化容積率的同時最小化建筑占地面積。通過這樣做，我們可以為高密度城市提供更多的開放空間。這一做法受到了那些想把孟買提升為全球化都市的人群的歡迎。對他們而言，孟買需要用高層建筑來創(chuàng)造一個更“引人注目的全球化身份”，而高層建筑群也是全球化城市倡議[2]提出的全球化都市的十大特征之一。這一想法同時得到了政策制定者的支持，他們認為這是孟買加速城市化進程的一個重要機會。他們著迷于上?；蚣~約等現(xiàn)代都市的天際線[3]。過去幾十年里上海的天際線發(fā)生的重大變化也為重新開發(fā)諸如帕雷爾在內(nèi)的老工業(yè)區(qū)注入了強大的信心。圖2顯示了在帕雷爾被當?shù)厝朔Q為古爾岡（新德里的衛(wèi)星城）的廠區(qū)聚落的空間轉(zhuǎn)換。在2000年，紡織工廠仍然在整個城市肌理中占據(jù)主導地位。

到了2009年，在鐵路沿線的西部地區(qū)我們可以觀測到，隨著紡織廠的拆除，新建筑也開始修建。而到2018年，高層塔樓完全代替了工廠，主導了該地區(qū)的主要城市特征。圖3描繪了帕雷爾的天際線，它儼然已經(jīng)是一個現(xiàn)代化的都市，雖然高層聚居區(qū)前依然存在著一些與鐵路相關(guān)的租賃用途建筑。孟買已經(jīng)擁有超過一百多座的高層建筑，而且還有更多的建筑在建設(shè)中。似乎一個全球化都市已然成型。然而，隨之而來的是中高收入群體的住房供應顯著增加，而保障房的供應仍然非常不足[4]，造成這種住房供應的差異是什么原因呢？

圖3 / Figure 3帕雷爾的天際線，孟買，2018The skyline of Parel, Mumbai, in 2018

圖4 / Figure 4位于孟買的一個城市社區(qū)帕雷爾的貧民窟安置住房。該地區(qū)曾是工廠區(qū)，現(xiàn)在取而代之的是新的辦公區(qū)與住宅開發(fā)項目Slum resettlement housing in Parel, an urban neighborhood of Mumbai. The area was used to populated with mill factories, which are now replaced by new of fi ce and residential developments

我們需要仔細研究一下帕雷爾的一個具體項目。該項目旨在重新開發(fā)拉賈斯坦邦舍屋瑞的城市貧民窟和新的政策路線。圖4中左側(cè)圖片顯示，現(xiàn)有的城市結(jié)構(gòu)（主要是城市貧民窟）正在被高層建筑所取代。當政府與開發(fā)商采用公共私人合伙企業(yè)（P3）模式運營時，目的是為了更有效地推進再開發(fā)。而政府和開發(fā)商之間的談判結(jié)果是，讓開發(fā)商在為貧民窟居民提供負擔得起的住房，同時有權(quán)建造豪華的價格昂貴的獨立產(chǎn)權(quán)公寓。開發(fā)商將有義務提供服務以維持經(jīng)濟適用房基本的運營，同時前5年不收取任何費用。圖4中的中間圖像提供了一個鳥瞰視角，在6幢經(jīng)濟適用房的旁邊矗立著5座樓層更高的豪華公寓大樓。該項目提供的豪華公寓面積要比經(jīng)濟適用房還多。此外，在建的這些保障性住房中，許多住房已經(jīng)或即將被廢棄。為什么城市貧民要離開保障房，即使沒有收取他們?nèi)魏钨M用，他們又將去哪兒呢？

“他們只是搬回了貧民窟”，一個來自當?shù)匮芯拷Y(jié)構(gòu)—城市設(shè)計研究院（UDRI）的城市學者解釋到：“不是因為貧民窟更好，而是他們所居住的高層建筑已經(jīng)不再適合居住了?！贝_實，5年后（可以更短或更久，取決于合同），開發(fā)商不再負責維護這些建筑。當電梯停止工作后，有許多老年人被困在高層建筑的樓上。沒有政府的幫助，他們只能靠自己。當我們走訪這些建筑時，一群正在漫長而黑暗的走廊里玩迷你板球游戲的年輕人吸引了我們的眼球。根據(jù)他們的說法，當供水停止時，老年人只能依靠他們來運送桶裝水維生。很難想象他們在被切斷了基本的生活供應后，是如何在20層的高樓里幸存下來。最終他們只能搬出去。

短短幾年后，如此高比例的貧困居民逃離高層經(jīng)濟適用房，這是社會網(wǎng)絡崩潰的結(jié)果。城市移民在很大程度上依賴于他們在家鄉(xiāng)的社會關(guān)系來尋找工作，這也是為什么他們在到達孟買時往往會和他們的同胞聚集在一起的原因。但是一旦他們重新被安置到高層建筑中，他們原本的社會關(guān)系就會消失，隨之而來的生計也會消失。目前的高層經(jīng)濟適用房并不能為城市貧民提供一個可持續(xù)的解決方案，除非同時能讓他們獲得謀生機會。

這種高層類型學的居住解決方案也加劇了交通堵塞。當這種模式大規(guī)模地向社區(qū)推廣時，會有非常多相似規(guī)模的項目同時開建。然而至少在可見的未來，并沒有更新道路系統(tǒng)或者增加公共交通運力的計劃，但居住密度已經(jīng)翻了一翻。此外，新增豪宅的居民是那些買得起私人汽車的富人。這一切將使現(xiàn)有的交通流量過載并極大減少可達性。最后，高層建筑多帶來的空間布局并不能提供一個令人愉快的居住環(huán)境。在圖4中，右側(cè)的圖像顯示了兩個住宅樓之間的狹窄空間。在“居者有其屋”運動已經(jīng)推出金融解決方案的當下，空間設(shè)計應該更多地強調(diào)公共衛(wèi)生、公共安全以及自然光照和清潔水源的基本權(quán)利。

圖5 / Figure 5在孟買實施的住房政策 / Housing policies implemented in Mumbai

圖6 / Figure 6達拉維貧民窟清理項目 / Slum clearance project in Dharavi

總而言之，高層的保障房并不能為城市貧民提供一個令人滿意而有效的居住解決方案。高層類型學的居住解決方案增加了交通壓力；與此同時，沒有足夠的基礎(chǔ)設(shè)施來容納更多的機動車。豎向發(fā)展城市的本意是為了最大化利用土地且使孟買升級成為一個更具吸引力的全球化都市。然而，高層保障房計劃的實施既不能以適當?shù)姆绞饺菁{城市貧民，并且不能長期支持他們。一系列的干預措施，應當在孟買分配其資源，尤其是土地資源之前就已經(jīng)完成，這樣孟買才有可能把其天際線打造成世界級城市的水準。其中，城市設(shè)計的干預策略可以借鑒學習先例，但不能直接照抄：上海的天際線是在為城市貧困人口提供社會住房的同時實現(xiàn)的，但那些從零開始的新城市開發(fā)建設(shè)計劃并沒有考慮城市貧民窟的再開發(fā)。為了使利益相關(guān)方能夠保持一種良性參與，應該建立一種更加協(xié)調(diào)的結(jié)構(gòu)，用于統(tǒng)領(lǐng)保障性住房的空間分布。其中，不僅要顧及對周邊社區(qū)的發(fā)展，而且要考慮到土地利用的規(guī)劃。

3.2 中層建筑類型解決方案：清除貧民窟

中層建筑類型解決方案提供了與高層建筑類型解決方案不同的方法來安置低收入的城市移民。在孟買，絕大部分低收入者生活在城市貧民窟。根據(jù)人口普查數(shù)據(jù)，孟買有一半以上的人口是貧民窟居民（2011年孟買城市人口普查）。為了滿足日益增長的住房需求，尤其是對于城市貧民，中央和州政府制定了一系列的住房政策[5]。圖5顯示了從1947年到2016年，孟買的住房政策是如何實施的[5]。根據(jù)制定的方法將這些政策分為4組，即：①中央政府實施的政策；②為消除城市貧民窟而采取的政策；③促進城市貧民窟改造的政策；④最近提出的住房政策。這4個類別的政策大致上也對應于時間順序。建筑和社區(qū)的空間布局中也有明顯的趨勢。它表明了一種自上而下和自下而上政策的結(jié)合。這一切歸功于許多致力于為城市貧民提供住房的非營利組織的共同努力。他們不僅從以前的計劃中吸取了教訓，而且也積累了非常多的當?shù)刂R，用于保障性住房的空間設(shè)計。最近的政策還將原本孟買市區(qū)以外的地區(qū)納入了孟買大城市區(qū)的整體考量。

其中一個影響孟買貧民窟清理的機構(gòu)是貧民窟改造局（SRA）。該組織成立于1995年，之后實施了多項貧民窟改造計劃。SRA的主要職責包括：①調(diào)查和審查現(xiàn)有的貧民窟地區(qū)；②制訂可行的計劃或貧民窟改造方案；③實施

圖7 / Figure 7 貧民窟改造局（SRA）的組織結(jié)構(gòu) / SRA organization structure

貧民窟改造計劃；④實現(xiàn)貧民窟改造的目標。在孟買最大的貧民窟達拉維，SRA已經(jīng)實施了一系列的貧民窟重建修復項目。大多數(shù)項目都采用了中層建筑類型的解決方案。圖6的下圖顯示了達拉維當前的空間狀況。中層建筑類型的房子在這個地區(qū)零星地分布著。它們中的大多數(shù)都是SRA參與的。圖6中上面的圖片是從貧民窟的屋頂上拍攝的，中層建筑類型的板磚房屋旨在為貧民窟居民提供正式的保障性住房。政府不僅每天提供幾個小時的電力，而且所有的房屋都與城市的下水道系統(tǒng)和供水系統(tǒng)相連。那些向政府支付費用的人就可以使用這些基礎(chǔ)設(shè)施。SRA的中層建筑類型改造計劃被證明是一把雙刃劍：它加速了貧民窟的清除，然而使得那些沒有資格獲得政府支持的貧民窟居民感到不公平。此外，更多的人會住在貧民窟里，他們希望有一天也能有資格享受國家補貼的住房。為解決這一問題，我們必須認真審視改善現(xiàn)有的貧民窟狀況與防止更多貧民窟的形成。

中層類型學的居住解決方案避免了高層類型學建筑存在的建筑維護問題，從而使用壽命會更長。中層類型學的居住解決方案也使政府能夠從當?shù)氐暮趷簞萘κ种袏Z取某些貧民區(qū)的控制權(quán)。此外，它還減少了非法活動并且還試圖將公共空間引入城市貧民窟內(nèi)。

如果重建項目在貧民區(qū)附近，那么中層類型學的居住解決方案就能幫助貧民仍然保持社會聯(lián)系。然而，那些被安置到郊區(qū)的人，確實遭受著遠離經(jīng)濟機會的痛苦。在目前的方案下，中層類型學解決方案比高層類型學解決方案提供的居住面積更少。圖7顯示，在SRA的8個分支中，沒有指定的部門負責貧民窟改造項目的城市設(shè)計質(zhì)量。一個良好的空間設(shè)計布局實際上可以提供切實可行且具有成本效益的方法來改進中層類型學的居住解決方案。城鎮(zhèn)規(guī)劃和財政部門的協(xié)同，可以提供更加可持續(xù)的住房方案，從而可以造福更多的貧民。值得一提的是，在發(fā)展新的中層類型學的居住解決方案時，應該解決一些問題：新來者很難進入原有的體系、現(xiàn)有的建筑缺乏維護、兒童無法獲得教育機會（尤其是英語口語的教學項目）。

總而言之，中層類型學的居住解決方案已被州政府采納為貧民窟改造的主要策略。依賴于便利的地理位置、高可達性的軌道交通以及良好的社會資本，它有潛力為低收入者提供更多的可負擔得起的住房和令人愉快的人居環(huán)境。

3.3 低層建筑類型方法：增量設(shè)計

圖8 / Figure 8新孟買貝拉坡（Belapur）區(qū)的增量住房項目Incremental housing project in Belapur, New Bombay

低層類型學建筑改造方法并不等同于提供低密度的住房。相反，低層類型學改造方法可以通過漸進性遞增的方式逐步改造達到高密度。這種漸進性逐步改造的方法被稱為增量設(shè)計方法。這個詞是由查爾斯·科里亞（Charles Correa）創(chuàng)造的，同時他利用這個概念改造了多個住房項目。增量式設(shè)計方法一方面是對溫暖氣候的一種回應，另一方面也是一種節(jié)省初始建設(shè)成本的方法，同時，整個過程與當?shù)亟?jīng)濟發(fā)展的前景形成良性互動。增量設(shè)計的目的是使低收入者能夠在能力范圍內(nèi)解決居住問題。增量設(shè)計的原則包括：①提供電力使用和污水排放的基本服務；②允許業(yè)主基本采用豎向方式擴大他們的住房，以適應多年來家庭的增長；③采用一種簡單的高度限制和對用地紅線的尊重。除此之外，保障性住房的整個轉(zhuǎn)型改造也掌握在居民自己手中。

查爾斯·科里亞第一次嘗試使用增量設(shè)計法可以追溯到1973年，這個項目叫作孟買的寮屋住宅?？评飦喸O(shè)計的寮屋住宅把開放空間安排在了中心位置，然后居住單元圍繞開放空間依次展開[6]。這一設(shè)計理念隨后被進一步發(fā)展為土地資源更為豐富的城市尺度的項目。在1983年，科里亞在新孟買設(shè)計了貝拉坡（Belapur）住房項目，這個項目現(xiàn)在被稱為納威（Navi）孟買。圖8顯示了從45m2到70m2的4種居住類型。它們一起形成了中間有公共開放空間的細胞結(jié)構(gòu)。貝拉坡居住區(qū)繼承了開放空間安排在中心的原則，然后居住單元圍繞開放空間依次展開的空間特性。它也為當?shù)鼐用竦脑诮?jīng)濟狀況的提高方面提供了多樣性的機會?！柏惱伦≌Ｊ娇梢詭椭?0%的孟買人解決住房問題”，科里亞說，“我們試圖將城市股權(quán)的模式加入到這個項目中來”。

增量式住宅方案試圖展示如何采用低層類型學建筑改造方法達到高密度社區(qū)的目的。此外，它還證明了可以通過空間布局的調(diào)整避免無處不在的混亂模式。增量設(shè)計不是相同單元布局的重復，而是一個個和而不同的空間單元組成的有機集群。圖9中的左側(cè)圖片顯示了在人工明渠或水道上的貝拉坡房屋的總體規(guī)劃，這些明渠和水道有防止洪水泛濫的功能性作用。圖9中右側(cè)的圖片顯示了它在新孟買的戰(zhàn)略位置以及它與孟買半島的聯(lián)系。35年后，當我們訪問當?shù)貢r，預期的轉(zhuǎn)變（基于居民的經(jīng)濟狀況）確實發(fā)生了。圖10內(nèi)的上圖顯示了剛完成時的住房，而圖10內(nèi)的下圖則顯示了2018年時住宅區(qū)的狀況。圖中間的房子被漆成綠色且保持著原有的規(guī)模和大部分的設(shè)計特色。然而，旁邊的另外兩幢房屋則已經(jīng)在往上加建。

圖9 / Figure 9查爾斯·科里亞(Charles Correa) 1983—1986年設(shè)計的納威孟買(Navi Mumbai)的增量式住房 / Incremental housing in Navi Mumbai, designed by Charles Correa, 1983-1986

采用增量設(shè)計方法的低層類型學建筑改造方法，為城市設(shè)計如何讓居者有其屋提供了一個范例。但有幾個問題值得深思。首先，盡管貝拉坡住房項目與新孟買的城市中心很近，但它的建筑密度和土地稀缺程度仍然很低。應該做些什么才能使其更加適用于孟買中心區(qū)這樣獨特的位置？其次，庭院空間提供了一個維護公共空間來培育社會資本的機會。然而，如果在都市層面上擴大規(guī)模，如何在社區(qū)中融入更多的經(jīng)濟活動是非常重要的。孟買的社區(qū)不僅是消費的場所，同時也是非常重要的生產(chǎn)場所。最后，與20世紀80年代相比，孟買面臨著截然不同的城市挑戰(zhàn)。我們應該進一步討論低層類型學建筑改造方法如何與例如低碳城市在內(nèi)的很多環(huán)境運動保持一致。

4 屬于每個人的家園

縱觀這3種干預措施，高層、中層、低層類型學的建筑改造方法，在為城市貧困人口解決居住問題時各有利弊。本研究的目的不僅是將它們作為獨立的方案，同時也討論了如何將這3種改造策略的優(yōu)點結(jié)合起來，為城市設(shè)計的干預創(chuàng)造協(xié)同策略。當孟買走向大都市的過程中，我們應該找到創(chuàng)新的設(shè)計策略來解決以下問題：

第一，將負擔得起的住房與孟買的城市化議程結(jié)合起來。高層類型學的建筑改造方法帶來了有關(guān)升級孟買基礎(chǔ)設(shè)施的辯論。政府官員和規(guī)劃者從西方(倫敦和紐約)和東方(上海和北京)的密集城市學習中意識到，地下交通可以有效地改善市中心的通勤狀況。如今，在班德拉的街道上行走，隨處可見“升級中的孟買”的標語。“升級中的孟買”，這已被用作宣傳正在建設(shè)的第一條地鐵線路的口號。然而，孟買的升級戰(zhàn)略不應以犧牲低收入者為代價。中低層類型學建筑改造方法都提供了可以對抗城市中心的紳士化的空間干預策略。在為孟買實施中低層類型學的建筑改造時，我們應該了解背后的空間邏輯。

第二，理解空間邏輯：認識到貧民窟的形成不是隨機的結(jié)果，而是對城市動態(tài)發(fā)展的合理回應。在達拉維貧民窟，正如我們前面所討論的，我們應該把粘土社區(qū)、橡膠社區(qū)和塑料社區(qū)都有機地結(jié)合起來，以最大限度地提高它們的生活環(huán)境。我們應該首先從這些空間形態(tài)中學習，然后重新配置它們以提供更高的密度和更舒適的棲息地。我們還應該意識到，空間布局應該具有靈活性，以適應未來的變化，例如財富的積累和家庭規(guī)模的增長。

圖10 / Figure 10新孟買貝拉坡（Belapur）區(qū)的增量住房項目Incremental housing project in Belapur, New Bombay

第三，未來的增量增長：漸進主義對經(jīng)濟狀況和城市發(fā)展階段都具有影響。城市設(shè)計干預的高、中、低類型學的解決方案可以為低收入者提供更加可持續(xù)的城市居住計劃。人們來到城市是為了尋求改變的，我們將為他們從棲居地—這個神圣的空間開始，提供更多改變的可能性。

Can Urban Design Intervention Contribute to Affordable Housing in Dense Cities:Three Paradigms of Spatial Strategy in Mumbai, India

Guan ChengHe, Rahul Mehrotra

1 Introduction: Low-income Household and Urban Migrants

People from poor areas move to economically vibrant cities for employment opportunities. From the early 20th century assembly line workers of industrial cities in the United States, to the end of the century vast number of rural migrants in coastal cities of China, urban migrants were not only enticed by higher wages but also being closer to social bene fi ts they are often deprived of. However, urban migrants to high density cities often fi nd themselves in shelters of the most adverse circumstance[1]. To improve the living conditions of the urban poor, the UN Habitat proposed a variety of strategies: To provide aordable social housing(UN Habitat for Humanity), to upgrade the infrastructure by providing basic civic services (UN Urban Themes), and to intervene through channels of education and training. The challenge to implement these schemes lies in the question of how urban design can better facilitate economically viable, socially just, and environmentally sound strategies.

This paper is organized as follows: The next section provides a contextual review of Mumbai’s spatial transformation. Section 3 discusses the three urban design interventions applied in Mumbai: High-rise, mid-rise, and low-rise approaches to accommodate low-income migrants and urban poor households. Section 4 reveals the spatial logics that connects dierent types of aordable housings and proposes design strategies of a more sustainable hybrid response in dense cities.

2 Spatial Transformation of Mumbai and Urban Design Intervention

This paper focuses on Mumbai where the sheer number of slum dwellers and the tension among different social classes for land use right create challenges for new types of affordable housing strategy. In 2016, the Mumbai Metropolitan Region Development Authority (MMRDA), a body of the Government of Maharashtra responsible for the infrastructure development, proposed a 2036 regional plan for Mumbai. In this plan, new urban centers are identified, new roads are projected,and new airports are proposed. If implemented,the spatial structure of Mumbai will change from monocentricity to polycentricity. Consequently,certain land use type will be redistributed to the peripherals. During this process, affordable housing should be carefully considered and integrated to other urban functions. Who to be relocated and which social classes are entitled to remain in the already overcrowded central city?

Figure 1 shows the spatial distribution of low-income settlements in Mumbai, housing an estimated number of over 10 million. Many agencies have attempted to address informal settlement, low-income housing, and urban slums in Mumbai metropolitan region. We summarized those approaches into three paradigms of urban design interventions.

3 Three Urban Design Paradigms Providing Afordable Housing for Low-incomes

There is not a one-size- fi ts-all solution for housing the urban poor. We realized that each project has its unique aspects. We categorize them in terms of spatial formations and building typologies.

3.1 High-rise Typology Approach: Urban Upgrade

In respond to the high demand of aordable housing, one approach is to develop high-rise buildings to maximize housing capacity and achieving higher Floor Area Ratio (FAR). The concept is not so different from those famous schemes proposed by design pioneers in the 20th century: Increase the compactness while minimize the footprints of buildings. By doing so, the goal is to introduce more open space to dense cities. This approach is welcomed by those who aims to bring up Mumbai’s status to a global city. For them, what Mumbai needs is to create a more “compelling global identity”, one of the ten traits to qualify for global fl uency, as proposed by the Global Cities Initiative[2].This idea is also supported by policymakers who deem it as an opportunity to accelerate Mumbai’s urbanization. They are fascinated with the skylines of modern cities such as Shanghai or New York[3].The skyline transformation of Shanghai in the last few decades also serves well the ambition to redevelop the old industrial areas such as Parel. Figure 2 shows the spatial transformation of the mill villages, known as the Girangaon by the locals,in Parel. In 2000, the textile mills were still the dominant building typology. In 2009, demolition of the textile mills can be observed in areas west of the railway chawl and new construction has started to take o. In 2018, high-rise towers took over the mills to form the main characteristic of the area. Figure 3 depicts Parel’s skyline as a modern city with the railway chawl in the foreground.There are over one hundred high-rise buildings in Mumbai and more are under construction. It seems that the contemporary global city has taken shape.However, the supply of affordable housing stock remains insufficiency while the supply for upper middle-income group rises significantly[4]. What are the reasons behind this disparity in housing?

We need to take a closer look at a speci fi c project in Parel. The project is to redevelop urban slums in Sewri and New Policy Lines. The left image in Figure 4 shows that the existing urban texture (mainly urban slums) is replacing by highrise buildings. The government aims to move the redevelopment forward more efficiently when it entered a Public Private Partnership (P3) with the developer. The outcome of the negotiation between the government and the developer is to grant the developer the right to build luxury market price condominiums while providing aordable housing for the slum dwellers. The developer is to deliver services to maintain the aordable housing up and running for the fi rst fi ve years free of charge. The middle image in Figure 4 shows the bird’s eye view of the six aordable housing facing the fi ve even taller luxury condominiums towers. The project produced more square foot of luxury fl ats than affordable housing. Moreover, of the affordable housing constructed, many have been or will be abandoned. Why do urban poor leave affordable housings, given them almost free of charge, and where do they go?

“They simply move back to the slums”, an urbanist from the Urban Design Research Institute (UDRI),a local research institute, explained, “not because the slum is better, but the units in the high-rise building is not livable anymore”. Truly, after fi ve years (can be shorter or longer depends on the contract), the developer is no longer responsible for the maintenance of the buildings. There are many examples of elderly people stuck in the upper fl oors of high-rise buildings after the elevator shop working. No help from the government neither,they are on their own. When we visit the site, a group of youngsters playing mini cricket game in the long and dark corridor caught our eye. According to them, the elderly people depend on them to deliver bucket of water when water supply stopped.It’s hard to imagine how to survive twenty stories above ground while being cut off from basic supplied. They move out fi nally.

The high percentage of residents in the affordable high-rise towers move out after a few years are also a result of broken social networks. Urban migrants rely heavily on their connections from back home to find jobs, that is why they tend to cluster with their fellow compatriots upon arrival. But once resettled into high-rise buildings, the contacts are lost and so are their livelihoods. The current high-rise typology does not provide a sustainable solution for housing the urban poor, unless it can engage them with economic opportunities.

The high-rise typology also exacerbates traffic congestion. Zooming out to the community at large,there are multiple projects of similar scale under construction. While there is no plan to update the road system, at least in the immediate future, or to increase public transit capacity, the density has doubled. Furthermore, the newly added household are those who can afford private automobiles.It will overload the existing traffic and decrease accessibility. Finally, the spatial layout of the highrises does not provide an enjoyable inhabitable environment. In Figure 4, the left image shows the narrow space between two of the residential towers. While the campaign of “Housing for All”have launched with fi nancial strategies, the spatial design should emphasize more on public health,public safety, and the basic rights to natural light and clean water.

In sum, the high-rise typology does not provide a satisfactory nor effective housing scheme for urban poor. High-rise typology creates more traffic without sufficient infrastructure to accommodate more population who are car owners. The intention of extending the urban grid vertically is to maximize land use capacity and to upgrade Mumbai to

be a more compelling global identity. However,the implementation of the high-rise neighborhood typology is neither envisioned to accommodate urban poor in a proper way nor to support them in the long term. A series of intervention ought to be done before Mumbai allocate more of its resources,especially land, to upgrade the city skyline to meet the standard of a global city. Among them, urban design intervention can refer to experiences from precedents but not to borrow them directly: The skyline of Shanghai is achieved while social housings are provided for urban poor and those schemes proposed for building new cities from scratch are not considering redevelopment of urban slums. To align the interest of all parties involved, a more coordinated structure should be in place to overlook the spatial con fi guration of affordable housing and the integration to neighborhood development and land use planning.

3.2 Mid-rise Typology Approach: Slum Clearance

The mid-rise typology provides approach different from the high-rise typology to house the low-income urban migrants. In Mumbai, a large percentage of low-incomes are living in urban slums.According to the census data, over half of the population in Mumbai are slum dwellers (Mumbai City Population Census, 2011). Catering to the increasing housing demand, primarily urban poor,the central and state governments have produced a range of housing policies[5]. Figure 5 shows housing polices implemented in Mumbai from 1947 to 2016. Bardhan et al.[5]categorizes these policies into four groups based on the approach of formulation, they are 1) central government implemented policies; 2) polices motivated toward the removal of urban slums; 3) policies promoting the redevelopment of urban slums; and 4) recently proposed housing policies. The four categories are roughly corresponding to a chronological order. There is a clear trend toward spatial layout of buildings and neighborhoods. It indicates the incorporation of both top down and bottom up policies. This is achieved by the effort of many non-pro fi t organizations who are taking initiatives toward housing the urban poor. The lessons learnt from previous schemes also accumulated local knowledge for the spatial design of affordable housings. The more recent policies also incorporated areas beyond the Mumbai proper to the Mumbai metropolitan regions.

One of the agencies in fl uences the slum clearance in Mumbai is the Slum Rehabilitation Authority(SRA). Founded in 1995, it has carried out multiple slum rehabilitation schemes. The SRA’s main duty includes: 1) survey and review existing slum areas; 2) formulate schemes or slum rehabilitation; 3) implementation of the slum rehabilitation schemes; and 4) achieving the objective of slum rehabilitation. In Dharavi, the largest slum by resident population in Mumbai, the SRA has implemented a series of rehabilitation projects.Most of the project assumed the mid-rise typology.In Figure 6, the lower image shows the current spatial condition of Dharavi. Mid-rise housings are sporadically spreading out in the area. Most of them are products of the SRA. The upper image was taken from the rooftop of a slum house. The mid-rise slab block building is intended to provide formal housing for the slum residents. The government provides electricity for certain hours a day and all units are connected to city’s sewer system and water supplied. People who move in pay fees to the government to retain their status. SRA’s midrise scheme turns out to be a double-edged sword:It speeds up slum clearance while create inequality for those slum dwellers who are not eligible for government support. Additionally, more would come to live in slums expecting that one day they will be eligible for state subsidized housings. To deal with this issue, priorities should be set whether to improve existing slum condition or to prevent more slums from formulation.

The mid-rise typology avoided certain maintenance issues that curtailed the lifespan of high-rise typology. The mid-rise typology also enables the government to take control over certain slum area from the local ma fi a. Furthermore, it serves as a conduit to reduce illegal activities. Additionally, it attempts to introduce public space to urban slums.

If the rehabilitation projects are built in the vicinity of the slum areas, the mid-rise typology can keep the social contact in place. However, those who are relocated to the outskirts do suffer being farther away from economic opportunities. Under the current schemes, the spatial configuration of mid-rise typology provides less residential floor areas than the high-rise typology. Figure 7 shows that among the eight subdivisions of the SRA,no designated branch is responsible for the urban design quality of the slum rehabilitation projects.A well-designed spatial layout can actually provide feasible and cost-effective way to improve the midrise approach. Together with the town planning and the finance divisions, a more sustainable housing scheme, with higher density and compactness,can be delivered. Though a few issues should be addressed while developing the new mid-rise scheme: New comers are difficult to get in to the system, the existing buildings are lack of maintenance, and children have no access to educational opportunities (especially English-speaking programs).

In sum, the mid-rise typology has been adopted by the state government as the main strategy for slum redevelopment. It has potential to provide more affordable housing and enjoyable habitat for the low-incomes relying on the convenient location,high accessibility to rail transit, and well-conserved social capital.

3.3 Low-rise Typology Approach: Incremental Design

The low-rise typology is not the equivalent of providing low density housing. On the contrary, the low-rise typology can achieve high density through an incremental growth process. The approach in response to the incremental growth is called incremental design, a word coined by Charles Correa,who has realized multiple housing projects using this concept. Incremental design is a response to the warm climate, a way to save on the initial construction cost, and a process deeply rooted in economic prospects. The purpose of incremental design is to make housing affordable to the low-incomes. The principles of incremental design include: a) Provide the very basic service of electricity and sewage connection; b) Allow property owners to expand their housings, most vertically,to accommodate family growth over the years; c)Keep the very simple rules of height restriction and respect to the property line. Other than that, the transformation of the affordable housing is in the hands of its residents.

One of the first attempt to incremental housing by Charles Correa can be traced back to 1973, a project called Squatter Housing in Bombay, the current day Mumbai. The Squatter Housing has the bene fi t of open-to-sky space and centrality where the units are arranged in clusters[6]. The concept is then further developed into urban scale project where land is more abundant. In 1983, Correa designed the Belapur Housing project in New Bombay, the current day Navi Mumbai. Figure 8 shows the four types of units ranging from 45 m2to 70 m2. Together they form a cellular con fi guration with public open space in the center. The Belapur Housing inherited the spatial characteristics of open-to-sky space and centrality. It also introduced the opportunity to higher diversity, in terms of residents’ social economic status. “Belapur Housing can accommodate 90% of Bombay’s income profile,” according to Correa, “We try to add the dimension of urban equity into the project”.

The incremental housing scheme attempted to demonstrate how to design high density community using low-rise typology. Moreover, it demonstrated that the spatial layout could avoid ubiquitous patterns. Incremental design is beyond the repetition of the same unit layout but an organic cluster of similar yet distinct spatial elements. The left image in Figure 9 shows the master plan of the Belapur Housing along the manmade Nallah or watercourse to prevent fl ooding. The right image shows its strategic location in New Bombay and how it links back to the Bombay peninsula. After 35 years, when we visited the site, the expected transformation (based on residents’ economic status)did occur. Figure 10 shows the housing condition right after completion (upper) and the incremental growth in 2018 (lower). The house in the center,painted green, remains its original scale and most of the design features. The other two houses on the side, however, have been expanded vertically.

The low-rise typology using incremental design approach set an example how urban design intervention can contribute to affordable housing. There are a few questions worth contemplating. First,even though the Belapur Housing project situates in close proximity to the city center of New Bombay, it is still dealing with much lower density and land scarcity. What should be done to make it applicable in central Mumbai? Second, the courtyard space provides an opportunity to maintain communal space to cultivate social capital. However, if scaled-up at the metropolitan level, how to incorporate more economic activities in the neighborhood is of great importance. Neighborhoods in Mumbai are not only places of consumption but production. Third, comparing with the 1980s,Mumbai are all facing very diffferent urban challenges. How can low-rise typology position itself to align with environmental campaigns such as low carbon city should be further discussed.

4 Land for Everyone

The three deign interventions, high-rise, mid-rise,and low-rise typologies, all exhibit pros and cons in regard to provide adequate housing for urban poor.The intention of this research is not only present them as independent schemes but also discuss how to combine the strength of all three approaches to create synergetic tactics for urban design interventions. As Mumbai moves toward a metropolitan urban region, we should find innovative design strategies addressing the following questions:

a) Integrate affordable housing with Mumbai’s urbanization agenda: The high-rise approach brought the debate to upgrade Mumbai’s infrastructure. Learning from dense cities in the western (London and New York) as well as the east (Shanghai and Beijing), government officials and planners are aware that underground transit can be an effective way to improve inner-city commute. Today, walking on the streets of Bandra, it is hard to miss the signs saying, “Mumbai is upgrading”, which has been used as a slogan to promote the first subway line which is under construction. However, Mumbai’s upgrading should not be achieved in the expense of relocating low-incomes.Mid- and low-rise typologies both provide alternative spatial interventions which can combat gentri fi cation.To implement mid- and low-rise schemes in Mumbai,we should understand the spatial logic behind.

b) Understand the spatial logic: Recognize that the formation of slums is not a random outcome but rather a logical response to urban dynamics. In the Dharavi slum, as we discussed earlier, the clay community, the rubber community, and the plastic community are all organized in a way to maximize their productivity around their living environment.We should learn from these spatial formations and reconfigure them to provide higher density and more enjoyable habitat. We should also be aware that the spatial layout should provide the fl exibility to anticipate future changes—an incremental accumulation of wealth and growth of family.

c) Incremental growth for the future: Incrementalism has a bearing on economic status and the stage of urban development. An urban design intervention marring high-rise, mid-rise, and low-rise typologies can provide more sustainable urban housing schemes for the low-incomes. People come to cities for changes, we shall provide them with the possibility to change, starting from the very place they live—a sacred place for everyone.