sustainability Article Is the High-Density Housing Layout Affected by River Direction? Lessons from Seoul, South Korea Youngsang Kwon *, Youkang Seo * and Jihyun Hwang Department of Civil and Environmental Engineering, Seoul National University, Seoul 08826, Korea; [email protected] * Correspondence: [email protected] (Y.K.); [email protected] (Y.S.); Tel.: +82-2-880-8200 (Y.K.); +82-2-880-7374 (Y.S.) Received: 19 December 2018; Accepted: 23 May 2019; Published: 28 May 2019 Abstract: This study analyzes apartment building configurations in waterfront residential areas relative to water flow direction and assesses the waterfront impact on apartment construction planning. It surveyed 197 apartment buildings around Yangjaecheon, Gulpocheon, and Anyangcheon, three branches of the Han River, a major South Korean river, to ascertain the correlation between stream flows and apartment building configurations. The apartments were classified into four spatial-configuration categories relative to the adjacent stream’s flow axis—perpendicular, parallel, diagonal, and other—and three orientation categories—east- and/or west-facing, south-facing, and other. South-facing apartments were predominant around west- and north-flowing streams. The proportion of east- and/or west-facing apartments built and the percentage of south-facing apartments were relatively low, indicating that apartment building layouts are more diverse around north-flowing streams than around west-flowing streams. A t-test analysis of east- and south-facing apartments’ proportions relative to stream flow direction was statistically significant, and there were relatively higher percentages of east- and west-facing apartments near north-flowing streams than west-flowing ones. This suggests that the relationship with rivers is still important in urban housing in South Korea, and the importance of landscapes over the river is of increasing significance for planning urban settlements. Keywords: high-density housing; apartment; riverfront; waterfront; apartment building layout 1. Introduction 1.1. Human Settlement and Waterfront Throughout the history of mankind, prominent cities of antiquity, where human settlement flourished, have been formed around waterfronts. Therefore, waterfronts have been closely related to urban space. Proximity to waterfronts has affected the economic development, social composition, and cultural formation of the cities that formed in the surrounding waterfront areas. These spaces have served as a driving force of urban growth, serving as harbors as well as sources of water for industrial use, and are considered valuable spaces for sustainable urban development [1,2]. Particularly, as waterfront areas provide a large, open, public space and create an open landscape, they have offered great opportunities for conducting cultural activities, providing amenities, and ensuring appropriate environmental conditions in recent decades [2–4]. Korea has traditionally considered the relationship with rivers as an important factor in determining the environmental condition of human settlements. This has been the case in many Asian countries, including China, which accept the concept of Feng Shui. In the later urbanization process, although high-density housing became a common type of residence, the relationship between the residence and Sustainability 2019, 11, 3013; doi:10.3390/su11113013 www.mdpi.com/journal/sustainability Sustainability 2019, 11, 3013 2 of 16 Sustainability 2019, 11, x FOR PEER REVIEW 2 of 16 theorder river to face was the still rivers, an important residences factor. were Traditionally, planned and in developed the case of as east–west south-facing rivers, ones, in order thus tofitting face the rivers,concept residences of Feng Shui, were which planned is andpreferred developed by Sout as south-facingh Koreans. However, ones, thus in fitting the case the conceptof north-south of Feng Shui,rivers, which in order is preferred to face the by Southrivers,Koreans. west-facing However, residences in the had case to of be north-south developed, rivers, which in do order not tofit facethe theFeng rivers, Shui west-facingconcept. residences had to be developed, which do not fit the Feng Shui concept. Many South Korean cities are situated near rivers due to the landscape consisting of many rivers and mountains,mountains, as as well well as as the the practice practice of geomancyof geoman [4cy]. The[4]. HanThe Han River River passes passes through through Seoul, theSeoul, capital the citycapital of Southcity of Korea, South and Korea, it has and played it has an played important an important role since role ancient since times. ancient Since times. 1950, Since the expression 1950, the “miracleexpression on the“miracle Han River” on the has Han been usedRiver” to symbolizehas been Southused Korea’sto symbolize economic South development. Korea’s economic Recently, thedevelopment. “Han River Recently, Renaissance the Project,”“Han River which Renaissance aims to revitalize Project,” Seoul’s which urbanaims to space revitalize centered Seoul’s on the urban Han River,space centered was launched on the [5 Han] (see River, Figure was1). launched [5] (see Figure 1). Figure 1. Hangang Renaissance Master Plan (Source: City of Seoul) Seoul).. The HanHan RiverRiver passes passes through through central central Seoul, Seoul, and itand flows it flows from eastfrom to westeast withto west various with branches, various suchbranches, as the such Jungrangcheon, as the Jungrangcheon, Anyangcheon, Anyangch and Tahncheoneon, and Tahncheon streams. Additionally, streams. Additionally, Han River Park,Han whichRiver Park, has been which developed has been alongdeveloped the Han along River, the providesHan River, an provides excellent an recreational excellent recreational place for Seoul’s place residents.for Seoul’s Research residents. on Research how the on waterfront how the is waterfro used bynt residents is used by found residents that the found waterside that the environment waterside hasenvironment a major influence has a major on the influence assessment on the of theassessmen qualityt of of the the surrounding quality of the residential surrounding areas residential [6]. areasIn [6]. the 1970s, the south side of the Han River was developed in earnest, and most dwellings were newlyIn developed. the 1970s, the During south this side process, of the Han all new River dwellings was developed were developed in earnest, as and high-density most dwellings apartments. were Innewly particular, developed. most dwellingsDuring this developed process, on all the new riverside dwellings were high-rise were developed apartments, as which high-density became apartments. In particular, most dwellings developed on the riverside were high-rise apartments, Sustainability 2019, 11, 3013 3 of 16 Sustainability 2019, 11, x FOR PEER REVIEW 3 of 16 thewhich preferred became housing the preferred type for housing development type for at developm the timeent because at the theytime obecauseffered riverfront they offered scenery riverfront and a congenialscenery and environment a congenial (Figure environment2). (Figure 2). FigureFigure 2.2. SouthernSouthern PartPart of Seoul (Gangnam) Deve Developmentlopment Plan Plan (Source: (Source: City City of of Seoul) Seoul).. RecentRecent surveyssurveys onon waterfrontwaterfront views afforded afforded by waterfront apartment apartment complexes complexes have have collected collected residents’residents’ opinionsopinions onon thethe urbanness,urbanness, habitability,habitability, andand designdesign qualityquality of waterfront areas. These These provideprovide base base data data for for analyzing analyzing and and understanding understanding resident resident attitudes attitudes toward toward the waterfront; the waterfront; attitudes whichattitudes are which crucial are for crucial developing for developing landscape landscape plans [7]. plans [7]. 1.2.1.2. StudyStudy PurposePurpose ThisThis studystudy aimsaims toto analyzeanalyze howhow thethe spatialspatial relationships between apartment apartment buildings buildings and and adjacentadjacent streams streams influence influence the the apartment apartment building building layout. layout. Originally, Originally, the the preference preference for for residences residences on theon souththe south side side was was evident evident in the in the housing housing prices, prices, including including those those of apartments,of apartments, in Southin South Korea Korea [8 ]. Although[8]. Although most Southmost South Koreans Koreans still prefer still south-facingprefer south-facing apartments apartments and residences, and residences, different apartmentdifferent typesapartment and configurations types and configurations are being adopted are being in accordance adopted with in accordance the abovementioned with the factors.abovementioned Recently, a growingfactors. Recently, interest in a landscape growing interest and waterfront in landscap viewse and has waterfront brought changes views tohas the brought type and changes configuration to the oftype apartments and configuration being built of along apartments the waterfront. being built In along residential the waterfront. areas close In to residential streams and areas other close water to bodies,streams factors and other such water as landscape bodies, factors and viewssuch as are landscape especially and likely views to are influence especially the likely configuration to influence of apartmentthe configuration buildings. of apartment However, buildings. few