Infill Development Research Articles

The Riyadh Urban Growth Boundary: An Analysis of the Factors Affecting its Efficiency on Restraining Sprawl

Recently, research on sprawl was increasing due to its impacts on the economy, society, and environment. Several studies have focused on the application of containment strategies to curb urban sprawl. Urban growth boundaries (UGBs) were among the containment policies adopted to tackle the issue of sprawling cities. This paper set out to undertake an analysis of the factors influencing the performance of the UGB of Riyadh City. A qualitative data analysis using NVivo12 software was adopted. To collect the required data of UGB, semi-structured interviews were conducted with nine experts involved in urban management, Riyadh city development, and other planning agencies. If the application of UGB policy in the western countries has managed to restrain more or less city sprawl, its replication to the case of Riyadh seems to have had some adverse impacts. That is, instead of controlling urban sprawl, it has stimulated it. The reasons may lie in the deficiency of monitoring and evaluation of urban studies, free provision of infrastructure, and lack of coordination between different city planning agencies. Understanding the factors affecting the UGB efficiency​will assist policymakers and urban planners in reducing the spread of scattered and leapfrog residential development, lowering the cost of service supply and promoting infill development

The changing position of housing estate neighbourhoods in the Helsinki metropolitan area

This paper addresses the under-researched phenomena of investments in the private rental markets in disadvantaged suburbs in Finland. Despite the application of a social-mixing policy in the Helsinki Metropolitan Area and the Nordic welfare model, suburban housing estate neighbourhoods built in the 1960s and 1970s have experienced a socioeconomic decline since the 1990s. According to several recent large surveys, housing estate neighbourhoods represent the least popular housing environments among Finns. Nevertheless, as the Helsinki Metropolitan Area is currently facing rapid population growth, these neighbourhoods have now become the target for heavy infill development, and ambitious city-led regeneration plans. Simultaneously, housing investment has become an opportunity in Finland for both national and, increasingly, also international real-estate investment companies, as well as for private households. We explore the resurge to invest in housing estate neighbourhoods through two case studies in the Helsinki Metropolitan Area. Using statistics and interviews with policymakers and institutional real-estate investors, as well as a review of policy documents as our data, we show the variegated ways in which the marketization and financialization of housing and urban renewal policies change the social geography of housing estates in the Helsinki Metropolitan Area.

Becoming walkable: relational and contextual effects of enhanced walkability

ABSTRACT This study aims to understand how infill developments with walkable policies influence not only the walkability of the modified area but also the proximate urban spaces located in the context. The paper uses a mixed-methods and a relational approach to conduct comparative research in the form of pre- and post-construction analysis in a recently pedestrianised street to evaluate how enhanced walking in the pedestrianised corridor affected the walkability of its adjacent spaces. Results suggest that the enhanced walkability in the pedestrianised street increased the walkability of the adjacent spaces. Then, the study adopts a critical stance towards current approaches of understanding walkability and argues this finding corroborates the idea behind assemblage thinking in the walkability debate; that is, walkability is a capacity that may or may not be actualised. Here, seeing walkability in terms of a “becoming assemblage,” emphasises the role of assemblage thinking in grasping the dynamics of walkability.

Improving local pedestrian-level wind environment based on probabilistic assessment using Gaussian process regression

Many wind comfort assessment standards have been proposed to evaluate wind comfort and safety in spaces with intended use for pedestrians, such as pathways, building entrance areas, amenity spaces, and outdoor sitting spaces. However, the optimization of the wind environment presents a unique combination of complexities in assessment, simulation, and design. Conventionally, designers rely heavily on wind tunnel experiments or computational fluid dynamics simulations based on which only limited proposals are examined to select the one with the best wind performances. A new design framework for proactively improving the wind conditions at various measuring positions is demonstrated in this paper. Gaussian process regression models are combined with the Latin hypercube sampling method to approximate the relationships between design variables and wind velocities at discrete locations. Gaussian process regression is a non-parametric model well-suited for modeling the non-linear and stochastic wind behaviors. Moreover, it can provide the prediction mean and variance, and the latter is incorporated into a prediction quality function to quantify the modeling uncertainty. In the case study, with the objectives of maximizing the winter and summer wind comfort and minimizing the modeling errors, the robust and near-optimal designs of a target building in an infill development project are explored using the evolutionary search algorithm. We believe that this framework can be migrated to other urban design practice to better predict and simultaneously optimize the microclimate performances at locations of interest, such as solar access, indoor ventilation efficiency, and thermal comfort.

Building to conserve: Quantifying the outdoor water savings of residential redevelopment in Denver, Colorado

Outdoor water use represents up to half of total urban water demand in many semi-arid and arid cities and presents a climate adaptation challenge in urban centers. As indoor efficiency and reuse improves, outdoor use amounts to an increasingly large portion of consumptive urban water demand. Infill development, or the redevelopment of single-family properties to more dense multi-family and mixed-use developments, is a growing trend in urban planning; however, the influences of infill on outdoor water demand are poorly understood. The current work utilizes a remote sensing-based methodology to calculate parcel-scale irrigation rates in Denver, Colorado and applies a novel resampling methodology to model the impacts of redevelopment on outdoor water use. Results for 2018 showed irrigation rates varied by almost 250 mm between park and commercial land uses, and mean single-family irrigation rates of 224 mm exceeded multi-family rates by 70 mm. In the Berkeley neighborhood, modeled redevelopment of 1,347 single-family parcels (39.5%) resulted in a 102,000 m3 (83 acre-feet, or 30.2%) reduction in outdoor use. Citywide analyses indicate reductions of 141,000 m3 (114 acre-feet, or 0.76%) of residential outdoor use per one percent increase in redeveloped single-family parcels. These savings are equivalent to new annual supply for 181 four-person households and may provide significant contributions towards climate adaptation. Results highlight the importance of the continued integration of land use and water supply for demand management within the urban planning process.

A new affordable housing development and the adjacent housing-market response

Background: Cities continue to grapple with a rising demand for housing, which affects affordability and the well-being of its citizens. This growth continues to put pressure on the delivery of adequate, affordable housing in well-located areas while the availability of infrastructure and proximity to economic nodes remains a challenge. This has led to increasing infill development of medium-density to high-density affordable housing in greenfield areas located adjacent to higher-income neighbourhoods.Aim: This study investigates how a new affordable housing development influences the locational and structural values of the adjacent, existing housing market.Setting: Transactional data of residential sales for two areas in South Africa are used to measure the value change. Both areas are located within an urban setting next to an open, greenfield area that was redeveloped for affordable housing.Methods: Two case studies are used and analysed with hedonic pricing modelling to identify and measure the value change for the locational and structural characteristics before and after the development of affordable housing.Results: The results reveal a changing housing market as the locational and structural characteristics change in value, further highlighting the importance of careful planning that preserves the existing market and also supplies affordable housing.Conclusion: The value of several structural characteristics of properties will change, revealing just how consumer preference responds when affordable housing is introduced in an existing housing market. Distance to an affordable housing project continues to influence the house market value and careful consideration should be made when planning to integrate an affordable housing development in an existing neighbourhood.

A robust metamodel-based optimization design method for improving pedestrian wind comfort in an infill development project

Constructing a new building inevitably modifies the microclimate in its vicinity. We propose a metamodel-based optimization method to devise near optimal designs that minimize building’s adverse impacts on nearby pedestrians’ wind comfort in hot and cold seasons. Four design parameters, i.e., building width, building depth, building height, and building orientation, are considered for a greatly simplified building design task. Specifically, computational fluid dynamics (CFD) analyses are performed to calculate the mean wind velocity, while all CFD experiment samples are determined through the Box-Behnken design of experiment method. Based on 54 CFD experiments, the relationships between building design variables and the summer and winter mean wind velocities within a specified assessment area are learned using the response surface methodology. Finally, a genetic algorithm with the desirability function as the objective function is applied to identify near optimal design options under the robustness control (i.e., family error rate λ) for response surface models. The framework is applied to an infill development project to highlight its suitability in a real application. The experiment results show that as λ gradually decreases from 1 to 0.05, the overall desirability index dwindles from 0.33 to 0.22, consequently generating a more conservative optimal design decision.

Modelling urban expansion of a south-east Asian city, India: comparison between SLEUTH and a hybrid CA model

Accurate identification of the dominant driving factors in the expansion of a city is essential for cellular automata (CA)-based urban expansion modelling. The current study aimed at analyzing the drivers of change for Vijayawada city, a tier-II developing city in south-east Asia, India and then applies them to model the future scenario of the city in a CA-based environment. Furthermore, the study also aims at comparing the efficiency of the renowned CA-based urban growth model, SLEUTH (Slope, Land use, Exclusion, Urban extent, Transportation, Hill shade), and a self-designed CA-based hybrid model developed in combination with genetic algorithm (GA) for developing future scenario of the city. The models were built, calibrated, and validated for the city using land use maps derived from temporal Landsat satellite images. Analysis of the statistical significance of the driving factors shows that the terrain and population density are the two dominant factors influencing expansion of the city. Both the models output on predicting the urban growth indicate that the available open spaces within the existing city extent gets further converted to built-up indicating infill development, and more growth occurs along the fringes of the existing city. Also, emergence of new urban centers merged with the existing city areas for predictions till 2050 and extended into the dense vegetation on the north resulting in further reduction of green cover around the city. Validation of both the models showed overall accuracy higher than 85%. The inclusion of the demographic variable and utilization of the GA ensured that the hybrid model performs better than the SLEUTH model. Analysis on the built-up densification of the cityscape showed a shift in the pattern of built-up dynamics over time. The built urban expansion scenario for Vijayawada informs urban modelers and policymakers the possible evolution of the city.

Revitalization of property asset on the Dumilah Waterpark through the infill development of new activities

Property assets owned by the city government should provide high benefits as a source of regional income. The asset is aging so that its productivity will decrease. The government is trying to revitalize assets to make them more productive. The purpose of this study is to determine the best utilization that can provide the highest benefit. The method used to assess the development of these assets is through the high best use approach. Several alternatives to the use of assets compared with the analysis of financial feasibility include the calculation of IRR, NPV, PP, ROI. The utilization of property assets that is more profitable for landowners, based on the results of the FGDs that have been carried out there is an opportunity to build a supporting facility for the development of Dumilah Water Park as a Hotel and Convention Hall. Both of these facilities have considerable economic appeal to support the function of the city of Madiun as a center for trade and services on a regional scale. Based on the calculation of financial feasibility at Dumilah Water Park with an initial investment amount of Rp. 60,354,000,000.00 then the Net Present Value is obtained of Rp. 6,258,119. Likewise, the Internal Rate of Return was obtained at 11.41%, greater than the 10% interest rate. Meanwhile, the Payback Period of this investment is 8 years with an ROI of 10%.

Quantitative evidence for leapfrogging in urban growth

Urban growth can take different forms, such as infill, expansion and leapfrog development. Here we focus on leapfrogging, which is characterised as new urban development bypassing vacant land. Analysing a sample of 100 global locations, we study the probability that land cover is converted from non-urban to urban as a function of the minimum distance to existing urban cells. The probability decreases with the distance but in many of the considered real-world samples it increases again just before the maximum possible distance. Comparing these empirical findings with numerical ones from a gravitational model, we discover that the characteristic increase can be found in both. Our results indicate that the conversion probability as a function of the distance to urban land cover includes three urban growth domains. (i) Expansion of existing settlements, (ii) discontinuous development of coincidental new settlements rather close to existing ones and (iii) leapfrogging of new settlements far away from existing ones. We conclude that gravitational effects can explain discontinuous development but leapfrogging can be attributed to a scarcity of developable land at long distances to settlements.

Irkutsk architectural appearance changes in the 1960s-2010s

The article highlights the changes in the architectural appearance of Irkutsk during the post-Stalin times. The development of the historical city in the Soviet period proceeded in accordance with the needs of the Soviet system: industrial facilities and mass segment housing were built; residential neighborhoods with a set of social and domestic facilities were created. Sometimes there was a successful weaving of the new forms into the established ones. In some cases, innovations destroyed the historical view of the environment. The contribution of architects and statesmen to the development of the city has been considered. In the conditions of a market economy, multidirectional trends have been indicated. Thus, on the one hand, the integrity and originality of the city centre is spoiled and distorted through the infill development. On the other hand, the demand for creating a comfortable city environment is reflected in interesting forms of the cityscape: new squares, monuments, fountains, and other objects appear. The city symbols are being updated, an attempt to brand Irkutsk has been made. The regeneration of the city environment leads to the introduction of 130 Kvartal quarter, which is a successful attempt to create a new public space. There are also other attempts to make the architectural appearance of the city more modern and its image – memorable.

Integrative governance processes towards sustainable spatial development – solving conflicts between urban infill development and climate change adaptation

Due to the high concentration of people and infrastructures in European cities, the possible impacts of climate change are particularly high (cities’ social, economic and technical vulnerabilities). Adaptation measures to reduce the sensitivity of a city to climate risks are therefore of particular importance. Nevertheless, it is also common to develop compact and dense urban areas to reduce urban sprawl. Urban infill development and sustainable spatial climate policies are thus in apparent conflict with each other. This article examines how German cities deal with the tensions between these two policy fields. Using six case studies, a new heuristic analysis method is applied. This study identifies three key governance aspects that are essential for promoting the joint implementation: instruments, organisation and interaction. Based on our case studies, we conclude that successful implementation can only be achieved through integrative governance including all three domains.

A multi-dimensional spatial policy model for large-scale multi-municipal Swiss contexts

Switzerland’s widely adopted spatial policy rejects the use of new land in favour of promoting the densification of existing buildings or brownfield developments. However, to date there has not been an assessment of the volumetric building reserves that are still available within the current building regulatory framework. This paper addresses this lacuna using a case study of the agglomeration of Lausanne. An automated spatial policy model with particular focus on building density and its volume in residential and mixed-use areas allows for building policy to be quantified, assessed and evaluated on a countrywide scale since it takes the location of the building lot into consideration and cross-references it with the correct building regulation. Three-dimensional comparison allows us to identify whether the maximum volume permitted under the building regulation is greater than the current existing building volume. For the test case, spatial policy model identified 38 hectares of available square metres for densification (‘building surplus’ in the context of existing buildings, either in the form of extending existing buildings or infill development) and 93 hectares of square metres available for new developments (brownfield development of vacant or derelict open land) of residential and mixed-use buildings. At the same time, almost all areas are allocated beyond Lausanne’s inner-city boundaries.

Can ceding planning controls for major projects support metropolitan housing supply and diversity? The case of Sydney, Australia

Local land use planning policies and decision-making processes are often perceived as a barrier to new housing production, particularly higher density housing in established areas. In the context of wider debates about the impact of local regulatory planning on housing supply and diversity, this paper examines the outcomes of a policy experiment that was introduced in the Australian state of New South Wales (NSW), which is home to the Sydney metropolitan region, in 2005. The Major Projects reform enabled developers of large projects, including residential and mixed use projects to bypass local planning controls and to have their project approved by the Minister for Planning on a discretionary basis, in many instances, negating the need for formal land rezoning. Based on a detailed analysis of development applications that were determined under the Major Projects reform, we examine whether ceding local land use regulations enabled housing approvals above what would be permitted under local land use policy and whether approved dwellings supported key metropolitan housing and spatial development goals, including increased housing supply and diversity through urban consolidation. We find that the reform did result in housing approvals, particularly for higher density infill development, that would likely not have been permitted by local governments. However, by 2016, not all approved projects had commenced. Overall the results highlight the limitations of ceding power to the market to achieve housing supply and affordability goals.

Urban infill development potential in Germany: comparing survey and GIS data

Limiting land take is an important sustainability target. To this end, infill development is a primary strategy. To implement this strategy, policy-makers need a reliable knowledge base on infill development potential (IDP), such as brownfields, vacant lots and underused lots. This study presents the results of the first comprehensive national survey of IDP in Germany. Almost 12% of German municipalities were contacted by questionnaire. In contrast to previous studies, this study also takes into account smaller towns and small-scale vacant lots, which would otherwise lead to a considerable underestimation. Additionally, a feasibility study shows how IDPs can be identified using a geospatial approach. Here, a procedure is presented that allows the identification of IDPs and the differentiation between vacant and underused lots by analysing urban morphology using nationwide and commonly available geospatial base data. The results provide a good basis for an initial inventory. However, to obtain more accurate results, additional specific data would be required, the accessibility of which is currently limited. With the development of an improved spatial data infrastructure combined with Open Data initiatives, geographical information system (GIS)-based procedures for the automated detection and monitoring of IDPs could become more important in future. <strong><em>Policy relevance</em></strong> If the objectives of land policy, especially the avoidance of urban sprawl, are to be achieved, then the more efficient use of already developed land is essential. At the strategic level of policy development, knowledge of land suitable for infill development is as necessary as knowledge of the land take. Currently, regular standardised questionnaire surveying is the effective method for analysing infill development potential (IDP) and its development on a large scale. Geospatial approaches can help to identify potentials, especially on vacant and underused lots. Thus, they have a considerable potential to serve as heuristic tools for local practitioners seeking to begin reflecting on infill development options. Policy-makers and planners should recognise this potential and develop it further in cooperation with the scientific community. However, decision-makers are not spared from weighing the appropriate density in the respective context—and this has not become easier under the impact of the current COVID-19 pandemic.

Assessing the effect of urban form on social sustainability: a proposed \u2018Integrated Measuring Tools Method\u2019 for urban neighborhoods in Dubai

Among the three pillars of sustainability, social sustainability has received the least attention, especially among the studies addressing the sustainable housing development in Dubai’s urban neighborhoods. Unfortunately, these neighborhoods are not showing enough vibrancy of their public spaces and amenities which seemingly undermined their social sustainability. The lack of a comprehensive tool that can assess the interlinked indicators of social sustainability in urban neighborhoods has urged the research to propose an Integrated Measuring Tools Method (IMTM), that incorporates relevant computational simulation techniques alongside the appropriate conventional qualitative tools. The proposed IMTM was utilized in assessing the social sustainability indicators within the urban form of an existing neighborhood in Dubai. The assessment revealed that various urban form characteristics including; density, land-use, mobility options, mobility networks, streets layouts, and the built environment’s safety and aesthetic qualities, are the main factors undermining social sustainability in the studied locality. The results informed a set of suggested redevelopment strategies/guidelines for this neighborhood that takes into consideration the exiting constraints and opportunities. These included; increasing density by infill development, redefining land-use to achieve diversity in housing types and decentralized amenities, diversifying mobility options, improving the spatial integration of the mobility networks while restraining the private cars movement, improving accessibility, enriching urban landscape, and finally enhancing the quality of amenities and services. A social sustainability redevelopment scenario was suggested based on these strategies. When compared to the exiting neighborhood utilizing the IMTM, it proved significantly better attainment of social sustainability principles. So, it might be claimed that the proposed IMTM and its outcomes proved to be a valid basis for assessing, redeveloping and validating social sustainability of existing neighborhoods with similar typology in Dubai, and potentially in the region.

Infill drilling and well placement assessment for a multi-layered heterogeneous reservoir

This paper presents an assessment of infill drilling opportunities in a complex multi-layered heterogeneous carbonate formation located in Abu Dhabi offshore. The subject field was developed last century and is currently undergoing further development with line drive horizontal wells. The field is being redeveloped for improved oil recovery at higher production rates with long horizontal wells. An infill assessment process is defined using sector model reservoir simulations for the specific reservoir. Reservoir simulations are performed on pattern sector models to establish the optimum grid for infill evaluation. Also, the models with an appropriate grid size are used to optimize infill placement (vertical and lateral well placement) and infill drilling timing for a couple of geologically similar areas. In the second step, the sector model results are applied to test the full-field infill development plan. The relatively homogeneous geological area shows very uniform displacement with 1-km spaced wells and gives no considerable benefit of incremental recovery through infill drilling. However, in a comparatively heterogeneous geological area, considerable incremental oil recovery is quantified. In brief, this paper presents a detailed infill drilling and well placement assessment process workflow for the re-development of a multi-layered heterogeneous reservoir.

Точечная застройка объектов жилого назначения как способ решения территориальных проблем (на примере города Казань)

An increase in the number of inhabitants in cities, urbanization processes and congestion in infrastructure lead to a shortage of territories in urban systems. One of the most common ways to search for internal urban reserves is the implementation of infill (compaction) development. The purpose of this work is to analyze the infill development of residential facilities as a way to solve territorial problems (using the example of the city of Kazan). In the article, infill development is understood as a deviation from the general urban planning plan, when the construction of objects occurs on sites adjacent to the existing development. The authors created a register of residential buildings in Kazan, built over the period 1860–2019, deciphered and compared satellite images of 2004 and 2020, determined the functional use of land plots that preceded modern development. Spot buildings are found throughout the entire city of Kazan. However, the process of compaction of the urban fabric is uneven—it is most intense in the central, historical part of the city, which is valuable from the point of view of investors, in which a significant number of various cultural, educational, scientific institutions and other socially significant objects are concentrated. The largest number of episodes of sealing development was recorded in the Vakhitovsky district. In the period 2001–2019. 33.9 % of the total number of residential buildings in the Vakhitovsky district were built, and a significant part of them is “included” in the existing planning structure and refers to the sealing building. Closer to the periphery and borders of the city, the need for sealing construction decreases—less intensive processes of housing construction are typical for the outskirts of Kazan—Aviastroitelny, Kirovsky, Sovetsky and Privolzhsky.

Spatiotemporal Change of Urban Sprawl Patterns in Bamako District in Mali Based on Time Series Analysis

For decades, urban sprawl has remained a major challenge for big cities in developing countries, such as Bamako. The aim of this study is to analyze urban sprawl pattern changes over time in the Bamako district using landscape index analyses. Four thematic maps of land cover (LC) were produced by applying the maximum likelihood supervised classification method on Landsat images for 1990, 2000, 2010, and 2018. Five landscape indexes were selected and calculated at class level and landscape level using FRAGSTATS software. The results showed that the dominant class for all the years within the landscape was a built-up class. Forest class covered the smallest area in terms of the percentage of land (%PLAND), and was the weakest class in terms of number of patches (NP) and largest patch index (LPI). Grassland is defined as the class with the highest fragmentation, farmland with the highest shape irregularity and more heterogeneity, and built-up with the highest patches. Class area (CA) of built-up showed the importance of sprawl in Communes 6, 5, and 4, respectively. Indices trends and land use/cover showed infill, scattered, and ribbon developments of sprawl. This study contributes toward monitoring long-term urban sprawl patterns using index analyses.

From underdetermined to overdetermined space: public/private interfaces and activities in residential alleys

ABSTRACT The underlying logic of two well-established urban design concepts, active use and active interface, while applicable to streets and activity centres, may have limited bearing on residual urban spaces. As such spaces can be perceived as problematic, they are often replaced with conventional forms rather than valued for their uniqueness. This study examines the relationships between public/private interfaces and activities in residential alleys in Melbourne, Australia. These alleys are undervalued urban features that sum to vast amounts of land in areas deprived of public space. They are reappropriated for social activities and are also used as access for infill developments. The findings show that the conventional infill developments create overdetermined conditions that limit social activities. In contrast, the impermeable and blank interfaces that would be problematic elsewhere enable a wide range of usage. The key quality of these preferred interfaces is underdetermination, where multiple possibilities could emerge and exist simultaneously.