Testing the Limits of Sustainability Assessment in Urban Regeneration: A Critical Analysis of Urban Planning–Design Consistency in an Iraqi Historic City Center

Historic urban centers face complex pressures resulting from physical deterioration, traffic congestion, functional change, and the need to preserve heritage identity. Recent studies on Iraqi urban environments also indicate increasing traffic pressure and mobility-related challenges that negatively affect pedestrian movement and urban spatial quality within dense urban centers. In this context, urban regeneration is no longer just about the physical restoration, but is now a planning and design process that will embrace a balance of mobility, accessibility, social vitality and historic urban character protection [1-3].

In recent years, sustainability assessment framework has been applied increasingly in urban regeneration projects to assess planning alternatives and aid decision-making. Typically, these frameworks contain environmental, social, economic and institutional indicators. But they are not only dependent on the quality of the assessment matrix, but also on how diligently assessment results are translated into clear decisions for urban design [4, 5].

Urban planning documents such as formal planning documents, maps, circulation diagrams, street sections and visual materials are typically the primary sources of evidence to consider when assessing planning decisions in data-poor urban settings and in many cities of the Middle East [6, 7]. Recent studies on Iraqi urban environments also highlight increasing spatial pressures and uncontrolled urban transformation processes affecting urban sustainability within rapidly changing urban contexts [8].

These documents should not be viewed merely as a description of the planning process, but should also be read as analytical evidence that can be used to test the consistency between the planning intentions and the urban design outcomes [9].

For this reason, the subject of this study is a formal urban regeneration project, which aims to re-evaluate the historic city center of Kufa (Iraq) in a critical manner. The study does not attempt to reproduce the original project or to validate its outputs, but rather focuses on how the results of sustainability assessment were used to inform decisions on pedestrian-oriented urban design. The relationship between planning goals, assessment indicators, mobility proposals, street scale design tools and observed outcomes on the street are emphasized.

The overall thesis of this research is that sustainability assessment frameworks can be useful in prioritizing urban regeneration alternatives but are less effective in isolation from related operational urban design mechanisms. For this reason, the study aims at highlighting the level of consistency between urban planning and design in the project and at unveiling the boundaries of sustainability assessment as an urban design tool for the pedestrian-oriented revitalisation of a historic urban context.

This study adds to the urban regeneration and plan evaluation literature by providing a document-based analytical framework to assess urban planning – design consistency of pedestrian-oriented regeneration projects in historic city centres. The study goes beyond the conventional sustainability assessment studies that are mostly based on the use of alternative ranking, and critically reviews how sustainability-oriented planning goals are realised into coherent spatial and urban design results.

The research also brings its own methodological contribution by paying attention to the planning document, the circulation scheme, the street section and the urban design drawing, rather than simply focusing on the products of the planning process. More specifically, it treats these documents as a source of analytical evidence instead of describing project products, especially in the context of historic urban areas, where data is scarce, such as the centers of Iraqi cities.

3.5 Research gap

Document-based and image-based analytical techniques have been increasingly used in recent studies to assess urban regeneration and historic urban environments, especially in cities where there is limited access to data [23, 24]. But there has been little critical research dealing with the real outcomes of urban design in formal regeneration projects that take sustainability as an aim of planning policies.

The literature available mostly deals with sustainability assessment in the strategic planning level or with the physical and visual evaluation of historic urban environments separately. Lack of attention has been paid, however, to testing whether frameworks for sustainability assessment are coherent with pedestrian-oriented planning objectives, and whether the observed spatial design outcomes are coherent with each other in the context of historic city centers.

Recent scholarship also emphasizes the importance of plan evaluation, implementation gaps, heritage-sensitive urban governance, and historic urban landscape approaches as analytical tools for examining the relationship between planning objectives and spatial implementation within historic urban regeneration projects.

This gap is especially significant in historic urban contexts like the city centres of Iraq, where planning documents, circulation schemes and urban design drawings are the key pieces of analytical evidence to consider when assessing regeneration interventions.

Thus, in this study, a critical evaluation framework based on documents is developed and used to investigate the relationship between sustainability assessment, urban planning goals, mobility structures and urban design outcomes in Kufa historic center in Iraq.

5.1 Study area and spatial environment

The study area was selected as the historic center of Kufa, Iraq; because it is one of the most important historic centers in the Iraqi historic urban context in terms of history and religion and urban importance. The area is an important heritage environment, featuring a high density of urban areas, a range of land uses, religious activities, traditional commercial functions, and growing mobility pressures.

The historic centre of Kufa also has symbolic and religious importance in the context of Iraqi urban heritage because the city's historic streets, the traditional market structures, religious destinations and patterns of pedestrian movement all constitute an important element of the city's spatial identity and historic continuity.

The study area is a complex environment of use that combines pedestrian circulation, vehicular circulation, conservation of heritage, and urban renewal needs. The conditions are conducive for exploring the connection between sustainability assessment frameworks and pedestrian-oriented urban design decisions.

The research is based on the documents of the regeneration, which consist of planning alternatives, circulation plans, street sections, urban design schemes and visual documentation of the historic urban environment.

The study area is illustrated in Figure 2, which shows the location of the study area, the regeneration boundary and the main urban structure analysed in this research.

Figure 2. Study area within the historic center of Kufa

The analytical evaluation was oriented around the selected indicators that dealt with pedestrian accessibility, mobility structure, human scale urban space, historic continuity and traffic dominance, in order to analyze the level of consistency between the proposed regeneration interventions and the planning and design.

5.2 Pedestrian-oriented planning and mobility structure

The circulation schemes analysed imply that the regeneration project formally embraces the principles for pedestrian planning by decreasing the flow of vehicles in part of the historical center and by creating pedestrian routes and systems of controlled accessibility.

The planning level of the sustainability assessment framework focuses on pedestrianization, accessibility and traffic reduction as main indicators of sustainable urban regeneration. This is a theoretical convergence of the planning documents on sustainability goals and mobility policies.

The proposed circulation structure and street organization, however, show that vehicular circulation still prevails for several major urban corridors surrounding and penetrating the historic centre. The proposed mobility structure is thus a partial translation of the pedestrian-priority goals to actual urban design interventions.

The analysis also points to the existence of a few sections of streets with the spatial structure of traffic, in which the permeability of pedestrian flow is reduced and the effectiveness of human-scale spaces in the historic material is lessened, as shown in Table 4.

Table 4. Evaluation matrix of planning–design consistency

The link between sustainability indicators and observed spatial outcomes indicates that the linkage between planning goals and urban design actions is not completely effective. Although the reduction of pedestrian use and mobility was explicitly addressed in the planning process, the spatial arrangement of a number of the key corridors remain to support the continued preeminence of the car in the sensitive historic centres.

This means that the connection between the indicators for sustainability and the urban design-control mechanisms is still limited. Therefore, planning intentions are not always manifested in coherent human-scale spatial configurations or continuous pedestrian environments within the historic urban fabric.

5.3 Urban design consistency and historic urban fabric

The visual and spatial analysis indicates that there are different levels of consistency between the findings of the sustainability assessment and the urban design interventions.

The most compatible solution in the sustainability matrix was the one that embraced the preservation approach, but there are still a number of proposed interventions that make changes to the space which may alter the continuity and visual coherence of the historic urban environment.

Proposed urban design treatments tend to enhance accessibility and space organisation for public use, although not all of them are clearly traffic independent, meaning that they do not match the principles of pedestrian-oriented urban regeneration.

Visual analysis of the historic town shows that there are significant discrepancies between sustainability-related planning goals and proposed interventions in space. There are several areas in the historic centre for which some irregular commercial signage, ad hoc extensions and fragmented façade treatments have caused a degradation of the visual quality, reducing the continuity of the historic urban character (Figure 3).

Figure 3. Visual fragmentation within the historic urban fabric

The difference between narrow, human-scale alleys and streets dominated by cars (Figure 4) is further evidence of the spatial conflict between pedestrian-oriented design principles and the persistence of vehicles in the dominant role of the major streets.

Figure 4. Human-scale versus traffic-dominated urban space

Further, some design interventions proposed also make spatial and visual changes, which are not sensitive to the scale of the historic fabric. These interventions are formally in line with sustainability assessment results, but slightly clash with the concepts of visual continuity and historic urban preservation.

It is important to retain a sense of continuity and the quality of pedestrian space in the historic urban fabric of Kufa; this is enhanced by its sensitivity.

The results have shown that subtle visual and spatial mismatch can happen at the urban design level and may be disregarded by sustainability assessment frameworks, especially if the assessment indicators are not directly tied up to detailed design-control mechanisms.

The spatial tension between the planning goals set for the street and the actual street configuration of several proposed urban interventions is illustrated by comparing historic alleys with streets that are dominated by traffic.

Table 5 presents the main inconsistencies found in the visual and spatial aspects of the proposed urban interventions, as a result of the analytical evaluation.

Table 5. Visual and spatial consistency assessment

The table shows that there are a number of urban design interventions that only partially support the desired sustainability goals, especially in terms of visual continuity and the quality of the space for walking.

5.4 Planning–design misalignment

The clear differences between planning objectives, sustainability indicators and the spatial outcomes that can be seen show a partial disconnect between planning intentions and urban design implementation.

Although pedestrianization, human-scale urban spaces and minimizing vehicular dominance are reflected in planning documents, some of the proposed design solutions still maintain the spatial organization of traffic in sensitive historic places.

The incompleteness of the sustainability assessment frameworks indicates that they do not automatically ensure consistent urban design results if they are not accompanied by design-control mechanisms that can translate planning goals into measurable spatial actions.

Figure 5 shows how inconsistencies occur in the process of implementing planning objectives into detailed spatial and urban design interventions.

Figure 5. Planning–design misalignment process

The analytical process shows that this discrepancy between the planning goals and implementation in space occurs in the translation of the sustainability indicators into the concrete work of urban design. This is what makes it possible that a formally sustainable planning alternative could result in spatial and visual inconsistencies in a historic urban context.

Table 4 shows that alternatives for the regeneration project have been split into two categories: strong and weak. Table 4 compares the regeneration alternatives in terms of their intensity, mobility structure, impact on the historic fabric and compatibility with sustainability, as shown in Table 6.

Table 6. Comparison of urban regeneration alternatives

The multi-criteria assessment showed that the alternative that prioritized preservation was the most suitable one when considering its compatibility with the sustainability goals, especially in terms of pedestrian access, historic continuity and low impact on the historic fabric.

The spatial and visual review of the proposed interventions, however, reveals that several design decisions have been rather intrusive and particularly in the organization of traffic and the configuration of street-sections. This mismatch suggests that in the context of the historic urban environment, sustainability assessment does not always produce a coherent urban design outcome.

The conclusions indicate that the integration of sustainability assessment frameworks can be successful in the strategic planning level to rank regeneration options, but less successful in controlling the urban design translation process in detail.

5.5 Linking planning policies to urban design outcomes

The link between the planning goals and the urban design products were explored by analysing how the policies for sustainability were interpreted into concrete spatial and mobility interventions in the historic centre.

The analysis shows that the introduction of sustainability indicators in planning documents is not necessarily linked to the full consistency between the planning intentions and the urban design implementation. Pedestrian approaches and historic preservation goals were formally adopted into the regeneration framework, but a number of proposed interventions continued to preserve the transportation-dominated spatial structure and the visual intrusion of changes in sensitive historic places, as shown in Table 7.

Table 7. Planning–design consistency evaluation matrix

The matrix shows that the implementation of sustainability-related planning policies into urban design interventions is not consistent in all spatial components. Pedestrian access and the arrangement of public space had moderate consistency, whereas interventions focused on traffic reductions and historic identity preservation showed less consistency between planning intentions and spatial outcomes observed.

This is a confirmation that sustainability indicators are not enough if they are not clearly linked to the urban design-control mechanisms that will guide detailed actions of the spatial level in the context of historic urban environments.

Table 8 outlines the connections between analytical indicators, visual and spatial evidence from the planning documents and figures, and evaluative judgments for critical assessment of planning–design consistency with respect to the regeneration project.

Table 8. Indicator–evidence–judgment analytical matrix