Stone Town, located on the East African coastline, is one of the region's oldest towns, distinguished by its unique spatial patterns and town development (Battle & Steel, 2001). Historical influences have played a unique role in shaping Zanzibar City, especially Stone Town, influencing its growth patterns and cultural characteristics. The architectural heritage values in Stone Town exemplify the Swahili urbanization, highlighting the cultural identity of its residents [(Rashid & Shateh, 2012); (Sheriff, 1995)]. The town's tangible and intangible cultural richness has garnered significant recognition both locally and internationally. Since 2000, it has been designated as a UNESCO World Heritage Site (Convention, 2000). Yet, with the escalating threats of rapid urbanization, particularly the neglect of cultural values in planning practices, Stone Town risks losing its cultural legacy. The decline of cultural values is also evident in other heritage towns in Tanzania, like Pangani, which shares similar cultural origins (Chami & Mjema, 2024). The obstacles faced by heritage sites are diverse and differ across regions. Sustaining the status of these sites has proven to be challenging in many parts of the world, owing to a variety of factors such as political decisions, investment pressures, and the impacts of climate change [(U.N.E.S.C.O., 2024); (Convention, 2007)]. However, it remains crucial to prioritize preserving cultural heritage sites, including built heritage, as they are not just historical artefacts but also essential drivers of socioeconomic and spatial development (Tweed & Sutherland, 2007). The significant contributions of conserving the authenticity of heritage sites are evident in various aspects that support human lives (Al-Sakkaf & , 2020). Since the 1990s, Zanzibar City has undergone significant unplanned urban expansion, particularly in the new city center adjacent to the historic Stone Town and its surrounding areas. The 2022 Population and Housing Census reported that Zanzibar's urban growth rate has reached 48% (Tanzania, 2022). However, over 80% of this growth has occurred informally, as previous studies have indicated (Kukkonen & , 2018) (Scholz, 2006). The primary reason for this rapid growth is the increase in population, which has reached 1.8 million at a density of 768 persons/km², making Zanzibar the most densely populated region in Africa (Tanzania, 2022). Furthermore, the three municipalities that constitute Zanzibar City—Urban, West 'A', and West 'B'—are home to approximately 819,944 residents, with around 13,715 individuals living in Stone Town [(Review, 2023); (Tanzania, 2022); (Source Title, 2022)]. Continued population growth has led to increased demand for basic social amenities, stress on the built cultural heritage, and environmental degradation [(Ali & Sulaiman, 2006); (Myers & , 2020)]. The deputy director of Zanzibar City, who oversees urban planning, stated that "..., Stone Town's built heritage exemplifies a sustainable model of urban growth, characterized by its carefully planned patterns and construction techniques. However, in the past two decades, rapid unplanned urbanization has rapidly eroded Stone Town's cultural identity, driven by increasing social and economic demands. For instance, the rising focus on tourism investments has led to modifications of historic buildings to accommodate modern hotel needs, which significantly undermines the authenticity of Stone Town's architectural identity" (Deputy city director, Interview, 11th March, 2024). The lack of synergy between planning regulations and conservation efforts has led to the deterioration of historically significant buildings like the House of Wonders (Also known as Beit el- Jaib) and the People's Palace, once the Sultan of Zanzibar's residence in the 19th century. These structures among others are now in serious disrepair. Scholars have affirmed that declining state of historical buildings, such as the House of Wonders, has raised significant concerns for both residents and visitors [(Chami & Lyaya, 2015); (Longair & , 2023)]. Inefficiencies in spatial planning and conservation practices have worsened violations of heritage regulations, leading to a decline in the authenticity of the built environment. Effective spatial planning in Stone Town could establish important benchmarks for the city’s overall growth and promote inclusivity, yet it is often overlooked. In contrast, new developments in the contemporary area of Zanzibar City have occurred in an ad hoc and unstructured manner, primarily driven by population growth as well as political and business demands [(HAJI & , 2006); (Myers, 2023)]. This has led to a fragmentation of the social fabric among residents, particularly following the introduction of gated neighborhoods.

Against this backdrop, the main objective of this study is to highlight the significance spatial values of Stone Town's built identity, which has often been overlooked in planning policies and practices. The study answers two main questions that are: i. What is the pivotal role that the built heritage of Stone Town can play in fostering sustainable Swahili urban growth? and ii. How do the community's perceptions and values of the heritage site impact the city's future growth? The possible answers to the research questions may highlight the community's priorities and define the key concerns that should be considered when creating sustainable development strategies for Zanzibar City, ensuring they are effective, impactful, and inclusive. Although the Revolutionary Government of Zanzibar has developed plans like the 2015 ZanPlan to promote sustainable growth and counter unregulated development, challenges remain (DoURP, 2015). Still, there is room for improvement in prioritizing the promotion of cultural identity to encourage more compact and inclusive sustainable growth patterns. As previous researchers have argued, cultural identity is vital in enhancing the sustainability of city growth [(Abdurahiman & , 2024); (Juma & Turner, 2019); (Tweed & Sutherland, 2007)]. Therefore, Zanzibar City's spatial dichotomy, encompassing Stone Town and the other side (Known as Ng'ambo in Swahili language) where the city's expansion and contemporary developments occur, requires a comprehensive understanding of the spatial relationships and influences these parts have on each other (Folkers & Muhammad, 2016). The land use planning in Stone Town has been designed to ensure that residents have convenient access to all essential amenities (DoURP, 2015). Thus, embracing the compact design seen in Stone Town, characterized by a high level of mixed uses, can promote equitable access to essential services and enhance the city’s resilience amidst ongoing urban developments (Juma, 2020). This form of growth is essential for Zanzibar City to achieve sustainable urbanization by enhancing compact urban patterns, ensuring the resilience of built structures, and fostering the protection of cultural identity. Consequently, this research has provided a clear understanding of the connections between planning practices and heritage conservation, emphasizing the need to recognize built cultural identity in the planning process.

Stone Town, which represents Swahili culture, is crucial for driving urban growth in Zanzibar City. Recognizing the importance of this historic town, it was necessary to understand the community's perceptions of the values existing to build identity in their lives as residents. As emphasized by (Sumartojo & Pink, 2018). Understanding the research context is key to gathering genuine data and valuable insights. Therefore, this study utilized expert interviews and a participatory planning approach to explore how Stone Town's built heritage identity could support Zanzibar City's urban development. In this study, the researcher used semi-structured interviews and participatory workshops. The semi-structured interview questions were especially advantageous in the following ways: First, using semi-structured interviews allowed the researcher to gain valuable information from the participants as they focused and provided more information on the issues concerning this research. Hence, it helped to prevent the participants from providing unnecessary information despite their in-depth explanations. Second, the researcher engaged the participants to fully express their perceptions without seeming provocative or linked with political views. Therefore, all the participants comfortably contributed by sharing their knowledge and experiences, knowing that their contributions would be presented anonymously. All the participants filled in the consent form, in which they agreed to the researcher's use of the collected data solely for this research, which was obtained at the beginning of each workshop.

The researcher selected a specific group of residents to participate in participatory planning workshops based on various characteristics such as age (18 and above), gender, knowledge or experience of Stone Town, and political affiliations. The workshops were divided into three sessions, each with 15 participants, totaling 45 individuals. To illustrate, the first 15 participants were residents of Stone Town and the new city center, the next 15 were individuals with rich experience in Stone Town, and the final 15 had strong political affiliations. These participants were selected from the community through the Ward or Shehia leaders (Shehia is a Swahili word that refers to the grassroots administration level). The workshops were co-designed with participants from Aalto University's WiT Programme who conducted a study titled "Stone Town in the Eye of the Beholder" and conducted in collaboration with Pamoja Youth Initiatives, a local NGO, to build trust and ensure objectivity in learning from the participants. During the participatory planning workshops, the participants were divided into small groups of five and given a simple map of Stone Town (see Figure 3). The facilitators supported each group to identify important places, memories, and aspirations that are closely linked to this old town.This exercise aimed to help the researchers understand their perceptions of the built heritage identity. Through this intensive exercise, the participants also shared their experiences within the groups and concluded by suggesting the best approaches to replicate these values in other areas within the city and the island as a whole. The workshops were documented through video and voice recordings, as well as photography. The diverse group of participants allowed the researcher to capture different perceptions of the built heritage identity and its roles in the urban development of Zanzibar City. Their knowledge and aspirations had a profound influence on highlighting the values of the old town and its potential for future growth. These inputs from the selected sample form the basis of the ongoing research aimed at suggesting planning frameworks to enhancing the conservation of heritage values and identity.

In case of experts Interviews, this research actively engaged various stakeholders, including government experts and non-governmental participants, in the interview sessions. The interviews included urban planners from the Department of Urban and Rural Planning of Zanzibar (DoURP), the Deputy city director responsible for Urban Planning, and conservation officers from the Stone Town Conservation and Development Authority (SCTDA). Additionally, environmental experts from the Zanzibar Environmental Management Authority (ZEMA), an Arts instructor from Nyumba ya Sanaa Zanzibar (Zanzibar house of Art institute), and Development control officers from the Development Control Unit were also part of the process. Involving non-governmental actors, the interview sessions included the Chief of the Africa Unit at UNESCO (Unit: CLT/WHC/AFR), Conservation Engineers from the Stone Town Conservation Society, Architect from Hifadhi Zanzibar, Archaeologists, Artists, and local tourism operators from the Colour of Zanzibar. These diverse participants have made significant contributions to understanding the core values of Stone Town's culturally built identity, providing invaluable insights for Zanzibar City's sustainable urban growth.

In conclusion, the participatory workshops and interviews were aligned with the research questions to that help the researcher understand the importance of continuously protecting the built identity of Stone Town. This involved exploring perceptions of how preserving the city's heritage values could contribute to social, cultural, spatial, and economic sustainability in Zanzibar City. Gaining these insights is crucial for developing effective strategies for achieving sustainable urbanization. Previous studies have highlighted the importance of embracing the local identity of communities in promoting sustainable urbanization [(Tweed & Sutherland, 2007); (U.N.E.S.C.O., 2016)]. Hence, through participatory planning workshops actively encouraged by the Department of Urban and Rural Planning Zanzibar since its establishment in 2009, the researcher has been able to exchange knowledge with the participants.

The results from the analysis of the collected data are presented in two main categories. The first category examines the spatial layout and functions of Stone Town that could be replicated in other parts of Zanzibar City to enhance sustainable growth and efficient land use. The second category focuses on the community's perceptions, emphasizing the significant role of cultural identity in urban development. The paper concludes that Zanzibar City's sustainable future is closely tied to its built cultural elements, emphasizing the importance of these two categories.

Stone Town's cultural heritage identity is a precious asset that unites the community in Zanzibar City, symbolizing architectural beauty and community integration. It is argued that the built cultural heritages are vital elements that bind the communities (Tweed & Sutherland, 2007). Cultural values, especially those related to the built environment, have been widely recognized to foster community interconnectedness and serve as potent stimuli for socio-economic development. Consequently, the Stone Town townscape features pedestrian streets connecting the seafronts to the bustling bazaar, leading to narrow residential streets with diverse forms of housing. The residential houses in Stone Town reflect their owners' cultural diversity, influenced by African, Arab, Indian, and European traditions. Therefore, Stone Town's built heritage comprises a blend of cultural elements that shape its unique urban architectural environment (Steyn, 2001). As noted by the Conservation Engineer from the Stone Town Heritage Society during an interview, "the architectural styles and construction techniques in Stone Town were specifically designed to suit the tropical climate. These buildings have a natural breathing system through their thick walls, large windows, and doors. Additionally,nearly all structures were designed with courtyards serving multiple purposes. I believe that if these construction methods were adopted in the new areas where the city has rapidly expanded, they could enhance resilience to climate change impacts and address other issues" (Interview with Conservation Engineer, March 28, 2024).

Moreover, the diverse architectural styles and planning patterns seen in Stone Town reflect the necessity for functional, supportive designs that cater to the town's needs. These architectural and planning values hold aesthetic importance and contain valuable knowledge for researchers and experts to draw upon. For instance, the urban planning techniques and vision implemented during those periods have persisted in providing the services sought by many residents. Therefore, the compact and inclusive urban planning patterns make Stone Town a vibrant laboratory for research in planning, architecture, and culture. However, rapid urbanization, evolving demands, and increasing extreme weather events underscore the urgency to reconsider conservation and growth strategies (Khamis & , 2022). Zanzibar City requires a transformation in planning, emphasizing the amplification of cultural elements and the adoption of sustainable growth principles.

In conclusion, this analysis underscores the importance of learning from the urban planning patterns in Stone Town. These insights could be used to develop new areas within Zanzibar City. The uniqueness of urban patterns and buildings in Stone Town highlights the advanced nature of concentrated urban development. As stated by the Conservation Director of the Stone Town Conservation and Development Authority (STCDA), "The urban planning and building patterns in Stone Town are well-designed and implemented, making it possible to improve the land uses if needed. This level of planning maturity implemented in the 19th century still significantly contributes to the city today, despite the growing challenges. It is therefore important to replicate some of these planning techniques and building fabrics in new places across the city, as their efficiency has proven successful, as seen here in Stone Town" (Interview with STCDA Director, March 28, 2024). As the population increases, there is a growing need for more deliberate urban planning that focuses on the efficient use of land and resources, including cultural values (DoURP, 2015). Zanzibar City, home to an estimated 819,944 individuals across three municipalities, including approximately 13,715 in Stone Town, experiences high population growth due to a birth rate of about 3.7 and immigration, contributing to a total population of around 1.8 million across the Zanzibar islands [(Review, 2023); (Tanzania, 2022); (Source Title, 2022)]. Hence, the Zanzibar City Authority could enhance urban environments by integrating cultural elements into planning and construction, similar to what we see in Stone Town. This approach would help in recreating the vibrancy, safety, accessibility, and security of the newly planned areas to the level achieved in Stone Town.

The promotion of sustainable urban growth in Zanzibar City needs to heavily rely on cultural identity. Stone Town in Zanzibar City features unique cultural aspects that support social and economic activities, facilitate community connections, and provide access to essential services and amenities. (Alem Gebregiorgis & , 2022) highlighted the importance of urban planning initiatives in addressing challenges such as rapid transformation and the impacts of climate change. Their research suggests that leveraging cultural and traditional practices can contribute to the safety and future of African cities. Integrating cultural patterns that define the Swahili culture could significantly benefit Zanzibar City in terms of social and economic aspects. Therefore, it is crucial to recognize the ability to stimulate sustainable urban development in Zanzibar City by accommodating cultural identity. Understanding the local communities' perception of Swahili culture can incorporate cultural values into practices that could help Zanzibar City address various social, economic, and environmental challenges [(Folkers & Muhammad, 2016); (Juma, 2018)].

This study analyzed the local community's perceptions to understand their aspirations for cultural values in urban growth within Zanzibar City. The findings reveal that the community's aspiration for cultural identity in Zanzibar City goes beyond the existence of the built heritage structure. For instance, residents of Stone Town, a historical part of the city and UNESCO heritage site, expressed their preference for living in this old town. The sense of belonging, interaction, and access to basic amenities are crucial elements many wish could be replicated in other parts of the city, particularly in newly planned and developed neighbourhoods. Creating a sustainable urban environment in Zanzibar City with a focus on balancing diversity with local cultural identities and values is essential. Striking this balance will represent the local identity and promote economic growth, environmental protection, and inclusive development, aligning with broader country development plans such as Vision 2050 (Commission, 2020) and the National Spatial Development Strategy (Muhammad, 2015). Given the limited land resources in the Zanzibar islands, there is a need for efficient spatial planning and land allocation. With this in mind, I argue that the future urban development in Zanzibar City could be closely linked to the built identity seen in Stone Town. It is evident that many of the planning initiatives proposed by the Department of Urban and Rural Planning have resonated along the same compact growth principles as those in Stone Town. However, enhancing cultural identity integration into urban planning policies is crucial for Zanzibar to achieve sustainable urban growth.

The abstract of this paper was presented at the Cities’ Identity Through Architecture & Arts (CITAA) Conference—8th Edition, which was held on the 17th - 19th of September 2024.

I would like to express my gratitude to my supervisors, Professor Saija Hollmén and Professor John Fien, for their dedicated supervision and guidance throughout this research. This paper would not have been possible without their exceptional support. Special thanks to the Aalto WiT programme 2023 participants Anna Koskinen and Lidia Nimri for their contribution to designing the workshops. I also want to thank Pamoja Youth Initiatives NGOs for their valuable contribution in conducting workshops that provided genuine insights from the participants. Additionally, I am grateful to the local community members, governments, and private sector experts for their wholehearted engagement and for sharing their knowledge and skills related to the subject of this paper. Their contribution has greatly benefited this study.