Analyzing the Impact of Administrative District, Urban Planning Zone, and Purpose of Building on Coworking Spaces and Flexible Workspaces—A Case Study of Sofia, Bulgaria

Abstract

This article provides an overview of coworking spaces and flexible workspaces in Sofia Municipality, Bulgaria. The study aims at examining whether the type of urban plan zone, the particular municipal administrative district, and the purpose of the building in which they are located have an impact on such modern workspaces. Existing spaces in the municipality were counted and classified according to the following criteria: origin of the operators, accessibility, level of specialization, purpose of the hosting building, location in a particular district, and urban planning zone. The average rent for Hot desk, Dedicated desk, Private office, and Virtual office was calculated for the territory determined by the research. The findings demonstrate that the number of coworking and flexible workspaces is influenced by the type of urban planning zone, the municipal administrative district, and the purpose of the building. The study also revealed that the majority of such spaces are concentrated in the zone of the old town center or in a mixed multifunctional zones and are located in administrative, business buildings.

1. Introduction

The terms “flexible workspace” and “coworking space” are often used interchangeably to describe modern, evolving work environments. However, they are not synonymous, as there are some fundamental differences between the two concepts.

A flexible workspace is an office environment designed to adapt to various working styles and arrangements. Unlike traditional fixed offices, flexible workspaces offer a range of environments, including private offices, shared desks, meeting rooms, and common areas, all tailored to meet the dynamic needs of businesses. The defining characteristic of a flexible workspace is its ability to adapt and modify the available space to accommodate the evolving needs of its users. In the scientific literature, flexible workspaces are described using several terms, including the Activity-Based Workplace (ABW), the new way of working, multi-use office, flexible office, Activity-Based Flexible Office (A-FO), and flexible workspace [1]. The A-FO is designed to offer a variety of shared work environments tailored to employees’ specific work activities. This approach has been adopted by numerous organizations worldwide, as it optimizes office space utilization, enhances efficiency and flexibility, and reduces facility costs [2,3,4]. Flexible workspaces are designed to support two primary categories of work: focused, independent tasks and collaborative, team-based activities. Typically, these spaces are divided into three main zones: quiet areas, semi-quiet areas, and collaborative work zones [5]. In addition to providing quiet zones for focused work to minimize distractions, managers and leaders should prioritize addressing workplace stress factors to prevent fatigue and loss of motivation [6]. Flexible working hours and locations allow employees to choose when and where to work, promoting a positive work–life balance, reducing burnout, and enhancing overall well-being [7]. Research has shown that transitioning from a mixed-type office to an activity-based flexible office (A-FO) leads to increased productivity, improved communication, stronger team cohesion, and greater employee satisfaction with the physical work environment [8]. Furthermore, such office settings contribute to employees’ social well-being [9]. Study findings suggest that office developers should pay special attention to privacy needs, as well as communication, personalization, seamless transitions between workspaces, and minimizing time spent searching for available workspaces [10]. Additionally, the active use of different work zones, workstation clusters, and individual workstations has been examined as distinct organizational layers of modern workspaces [11].

A coworking space is a shared work environment where individuals from various companies or professions come together to work. Key characteristics of coworking spaces include flexibility, an open workspace, and a social work atmosphere [12]. Freelancers, entrepreneurs, startup companies, and small teams frequently choose coworking spaces for their networking opportunities and cost-effectiveness. A study examined the relationship between networks developed in coworking spaces and business performance [13]. These spaces contribute to the transformation of local creative ecosystems by enhancing the competitiveness of micro-clusters [14]. Additionally, community-organized events foster growth and collaboration among members [15].

A significant advantage of modern workspaces compared to traditional ones is the flexibility they offer, allowing companies to utilize both “flexible workspaces” and “coworking spaces”. One study has identified criteria for assessing the level of workplace flexibility [16]. Coworking spaces are ideal for networking activities among individual team members, while flexible workspaces are better suited for larger teams or departments that require greater privacy or customized settings. Depending on the strategic goals, an organization can choose either flexible workspaces or coworking spaces [17]. The paradox of collaborative work in coworking spaces and flexible workspaces lies in balancing the need for quiet, focused environments with the desire for social interaction [18]. These workspaces represent a business model that combines the best features of various environments to promote business development. This creates a mixed setting often absent in traditional offices—a blend of social interaction, the comfort of home, and the professional atmosphere of a traditional office. Furthermore, these modern work arrangements contribute to sustainability by reducing greenhouse gas emissions associated with work-related travel [19].

The first coworking space was established in 2005 in San Francisco, USA, by Brad Neuberg [20]. He introduced a novel workplace concept that addressed the limitations of traditional office spaces and working from home. Similar spaces emerged around the same time in Europe, primarily in Germany and Austria [21]. In urban agglomerations and major European cities, coworking spaces are no longer a novelty and are experiencing dynamic growth [21]. With approximately 148 operators, Europe boasts 6850 coworking spaces, with an expected annual growth rate of 4.7% [22]. According to Coworker, one of the largest online platforms for discovering and booking coworking spaces and flexible workspaces worldwide, 11,121 spaces are registered across Europe [23]. The growth of coworking spaces and flexible workspaces is driven by the high level of user interest in the services they offer. Customers have the flexibility to book desks, meeting rooms, small offices, or comfortable “on-demand workspaces” [24]. The shift toward hybrid working practices during the COVID-19 pandemic prompted many large office-space providers to adapt their offerings, incorporating flex-spaces with a coworking component [25].

Researchers must adopt a broad approach to studying the coworking phenomenon, as it intersects with various research areas, each contributing to a comprehensive understanding and offering potential for intriguing investigations [26]. The scientific literature examines coworking spaces and flexible workspaces from multiple perspectives, including the impact of space design on business outcomes and strategies to enhance user interest by promoting high levels of productivity [27]. The impact of spatial planning and workspace design on its users has been studied [28]. Research has identified the varying interests of office employees to address work ethics and business ethical challenges related to professional collaboration, competition, and power dynamics in future hybrid work models [29]. Additionally, the effects of different uses of modern workspaces on energy consumption intensity, heating and cooling loads, and the thermal comfort of occupants have also been examined [30]. Another study examined the impact of occupant behavior on energy consumption in various types of office buildings that house workspaces, as well as the corresponding spatial strategies employed in workplace design [31]. Some researchers emphasize the importance of identifying and prioritizing the needs of workspace members [32,33]. Others focus on key attributes they consider most important when selecting a specific workspace, such as interior design and accessibility [34]. Coworking spaces offer a supportive environment for entrepreneurship while also contributing to urban mobility and sustainability [35]. Research has explored the spatial relationships between collaborative workspaces and specific points of interest, identifying locations that can serve as daily destinations suitable for the typical lifestyle of working individuals [36].

The economic viability and sustainability of coworking businesses depend on both external factors (such as location, surrounding area activities and amenities, and accessibility of the structure) and internal factors (including the availability of optimal space to meet demand, the distribution of the workspace into different environments for various purposes, the quality of services provided, and organizational factors like contract types, service costs, and flexibility of working hours) [37]. Additionally, the location of coworking spaces is influenced by factors such as population density, access to broadband internet, and the proportion of individuals with higher education [38]. In addition, the available coworking spaces have a beneficial effect on the improvement of the surrounding public space and contribute positively to urban revitalization, both economically and spatially [39,40,41].

A comprehensive review of English-language scientific publications on the Web of Science platform regarding coworking and flexible workspaces revealed that no study provides a holistic analysis of these modern spaces in relation to the impact of urban planning zones, municipal administrative districts, and the designated use of the buildings in which they are located. Within the territory of Sofia Municipality, Republic of Bulgaria, this topic has also not been explored. This research is the first of its kind to examine coworking and flexible workspaces from this perspective. Given the rapid development of modern workspaces both in Bulgaria and globally, the study is highly relevant and is expected to make a significant theoretical contribution to the scientific literature on urban planning and development.

The Republic of Bulgaria on the map of Europe and the Sofia Municipality are highlighted in red in Figure 1 and Figure 2 [42,43]. Sofia Municipality has a population of 1,274,290, according to the latest population and housing census in 2021 [44], which accounts for 19.54% of the total population of the Republic of Bulgaria. Covering an area of 1349 km², it is the second-largest municipality in Bulgaria [44]. It is the only municipality in the Sofia Region. The capital of the municipality is Sofia, the largest Bulgarian city, with 1,183,400 inhabitants [44].

According to the provisions of the Law on the Territorial Division of Sofia Municipality and Large Cities [45], Sofia Municipality is divided into 24 administrative districts, as shown in Figure 3 [46].

In Sofia Municipality, the business activity rate, which represents the relative share of economically active individuals in the total population, is 78.6, while the employment rate, reflecting the relative share of employed individuals in the total population, is 75—the highest values in the country. Sofia Municipality also boasts the lowest unemployment rate, at 4.6, indicating the relative share of unemployed individuals in the total labor force [47]. These favorable economic conditions contribute to the presence of numerous coworking and flexible workspaces within its territory.

The study aims to test the hypothesis that the type of urban planning zone, the municipal administrative district, and the purpose of the building in which coworking spaces and flexible workspaces are located influence their presence and development.

The object of the study is coworking and flexible workspaces within the Sofia Municipality of the Republic of Bulgaria, which is the most populous and economically advanced municipality in the country. Given this status, it logically accommodates the largest number and variety of flexible spaces, making the research representative.

To achieve the aim of the study, the following research tasks were set:

1.

To count the active coworking and flexible workspaces operating both in general and according to the following criteria:

• Type of operators (local or international);
• Accessibility (regular working hours or 24/7 availability);
• Specialization (highly specialized or multi-purpose).

2.

To count the coworking spaces and flexible workspaces based on the following criteria:

• Municipal administrative district;
• Type of urban planning zone;
• Purpose of the hosting building.

3.

To map the active spaces and interest clusters on separate maps.

4.

To gather information on rent per workplace and calculate an average.

5.

To analyze the results of the study on the impact of the type of urban planning zone, the particular municipal administrative district, and the purpose of the building on such modern workspaces.

The article is organized as follows: Section 1 provides a literature review, justifies the relevance of the topic, and defines the object, purpose, and tasks of the study. Section 2 presents the time frame, spatial scope, and methodology of the current research. The main results are shown in Section 3. This is followed by a discussion (Section 4) and conclusions (Section 5).

2. Materials and Methods

The study was conducted over a six-month period, from the beginning of May to the end of October 2024, within the territory of Sofia Municipality in the Republic of Bulgaria. The methodology includes classical research methods, empirical methods such as observation, counting, and comparison, and combined methods like analysis, synthesis, inductive reasoning, and mapping.

The research started by counting the active coworking spaces and flexible workspaces within the territory of Sofia Municipality. The software application Google Maps [48], which provides detailed information on geographical areas and sites around the world, was used for this task. The key phrases “Sofia coworking spaces” and “Sofia flexible workspaces” were applied. Important information about each site was extracted, including the website, phone number, address, opening hours, driving directions, access on foot, by public transport, and the best cycling route to the destination. Additionally, information about nearby social and cultural infrastructure sites, shopping centers, hotels, shops, and restaurants was gathered. Photos and customer reviews were also collected for each space.

In addition, the platform Coworker [23] was used for identifying and including spaces to the list.

The counted spaces were mapped. The map reflected the location of each space and its distance from the city center.

The information contained in the map “Points of Interest in Sofia Municipality”, available on the GIS portal of Sofiaplan [49], served as the basis for generating a separate map. This map displayed coworking spaces and flexible workspaces, as well as specific clusters of interest related to transportation and communication infrastructure, green spaces and sports, culture, science, administrative services, and social infrastructure.

Websites for coworking spaces and flexible workspaces were used to obtain valuable information on various aspects, including prices, subscription plans, payment and booking methods, amenities and services, available zones and workstations, accessibility, parking availability, benefits, and particular features. Additionally, information was gathered about the buildings housing each workspace, the type of users for whom the workspace is suitable, and any unique characteristics that make each space stand out.

The website of iSofMap [50], a GIS application for visualizing free cadastral information about the Sofia Municipality, was used. Additional bookmarks were added to the base map to provide further data about each coworking space and flexible workspace by its address. This included information about the administrative district, the purpose of each building, the urban planning zone according to the Urban Masterplan of Sofia Municipality, and the development parameters of each zone.

References from the cadastral map of Bulgaria and the cadastral registers for land properties, buildings, and independent objects in them on the territory of Sofia Municipality, used for coworking and flexible workspaces, such as identifier, administrative district, type of ownership, type of territory, permanent use, area, and purpose of the building, were collected from the portal for electronic administrative services “Cadastral-Administrative Information System” of the Geodesy, Cartography, and Cadastre Agency [51].

Several coworking spaces and flexible workspaces were visited to gain insight into the environment and work opportunities provided by each space for shared services.

Due to the fact that the reviewed spaces are typically part of mixed-use office buildings, information was gathered from reports on the development of the office real estate market in Sofia over the past five years, published by Colliers International, a leading international company specializing in real estate and investment management services [52].

Other relevant research reports on office real estate in Sofia for the same five-year period were published by Forton, a leading commercial real estate consultancy, and Cushman & Wakefield’s strategic partner for Bulgaria [53].

Data on the number of new administrative buildings within Sofia Municipality, as well as the built-up area of each, was collected from the website of the National Statistical Institute [54].

Information from business directories on the territory and economic development of the different districts of the municipality, along with data on the main municipal infrastructures, such as transport, social, and cultural facilities, was found on the website of the Sofia Investment Agency, which is part of the general administration of Sofia Municipality [55].

3. Results

The research revealed that within a period of 12 years, from the inauguration of the first coworking location in the city of Sofia in the administrative district of Lozenets in 2012, by the end of October 2024, there were 66 active coworking spaces and flexible workspaces in Sofia Municipality. The number of spaces in the next three largest cities in Bulgaria—Plovdiv, Varna, and Burgas—are significantly fewer than those in the capital [56,57,58]. In the capital, 31 spaces are operated by single-location operators, and 11 spaces are operated by multi-location operators.

The points marked in red on Figure 4 illustrate the location of these spaces on the map of Sofia Municipality. It was observed that the majority of the spaces are located within walking distance from the city center, within a 1 km radius—27 spaces in total. This is followed by 25 spaces located 5 to 9 km from the city center. Only 16 coworking and flexible workspaces are situated within a 1 to 5 km radius.

Figure 5 clearly highlights the proximity of coworking and flexible workspaces to specific clusters of interest, including transportation and communication infrastructure, green spaces and sports facilities, cultural sites, administrative services, social infrastructure, and scientific.

Spaces managed by local operators are 52 and other 14 are managed by international entities (Figure 6).

Some coworking spaces and flexible workspaces initially launched with a specialized focus but have since transitioned to offering broader, multi-purpose services. These spaces are now suitable for a wide range of users, including freelancers, digital nomads, entrepreneurs, startups, established companies, and more (Figure 7). For example, Biz Hub Coworking [59], with locations in City Park and Mladost 1A, exemplifies this trend by catering to diverse professional needs. Other examples are Apex Hub Innovation Space & Coworking [60]; Networking Premium Coworking space [61], with locations at Rakovska Coworking, Gurko Panorama Coworking, Networking Coworking Vitoshka; Puzl Coworking [62]; Work&Share Coworking space [63], with locations at Dianabad and Work&Share Synergy in Tech park; MyFlex [64], with locations at Megapark and Twins center; WorkBetter [65]; Campus X [66]; OvertAim Coworking Office [67], with locations at South Coworking Space, Overtaim Park Coworking Office, Overtaim Sport Coworking office; Entract 127 [68]; Korner Sofia Coworking [69]; COXO [70], MaxCoworking Sofia [71]; Betahaus Bulgaria [72], with locations at Betahaus Shipka 6, Betahaus Slaveykov Square, Betahaus Sofia Tower, Betahaus ABC; SODA Workspaces [73]; Cre8 Coworking [74]; Trevor Workspaces [75], with locations at Trevor Workspaces Vitoshka, Trevor Workspaces Dondukov, Trevor Workspaces Lozenets; Social Station Cowork Club [76], with locations at Social Station Cowork Club Center, Social Station Cowork Club Belite Brezi; ATRIUM Business Center & CoWorking [77]; VworkX [78]; Regus [79], with locations at Sofia Airport, Landmark Building, Boulevard Totlebben 53–55, Emblema, BSR Sofia One, European Trade Centre, Boulevard Christopher Columbus 41; MOVE.BG [80]; SPOILER [81]; Coshare|HIVE [82]; Boyana Tech Labs [83]; This Way [84]; Sterling Serviced Office Group [85]; Sketch—Office Spaces & Coworking [86], with locations at Sketch Ring Tower, Sketch Srebarna; WorkNomads LAB Hotel—Coliving & Coworking [87]; ParkShared [88]; Masstab [89]; Pirin CoWorking [90]; Crystal Business Center [91].

Nine spaces remain specialized:

• For psychological and psychotherapeutic activities—Hour SPACE [92]; New SPACE [93];
• Cultural and creative spaces—for art, exhibitions, including creative workshops, product photography studios: KO-OP Coworking & Art [94]; Dreamer’s Space Art Coworking [95]; Artground Centre [96];
• Experimental and Digital Spaces—The Resonator Co-working Café [97], which includes various labs such as the Electronics Lab, Fab Lab, Device Software Lab, Extended Reality (XR) Lab, and Sound Lab; the Design Lab [98], offering facilities for architects and designers; the Woood Makerspace [99], featuring separate work areas for ironwork, carpentry, ceramics, and digital projects, equipped with tools and machinery; and Groworking by SOFIA TECH PARK [100], which hosts special clubs, including the AI Club, The Anonymous Innovators Club, Club Biotechnology & Life Sciences, Club “Bulgarian Science”, Business Club, Drone+ Club, The Robo Club, Space Club, Food Tech Club, and Greenhouse Club.

Exterior and interior photos of several buildings and spaces, extracted from the websites of the respective spaces [72,91,98], are shown in the Figure 8, Figure 9, Figure 10 and Figure 11 [101,102,103,104].

In terms of access, 57 coworking spaces and flexible workspaces are available 24 h, seven days a week, and only 9 are open during the standard hours 9 a.m.–5/6 p.m. (Figure 12).

Figure 13 illustrates the distribution of coworking spaces and flexible workspaces by municipal administrative district. It can be noted that coworking and flex facilities are located in 14 districts, while in the remaining 10 districts, there are none.

Coworking spaces and flexible workspaces are situated in buildings serving various purposes. The buildings in the territory of the Republic of Bulgaria are classified according to the Classification of the Types of Construction for Buildings, Technical Infrastructure Facilities, and Independent Units, as specified in Annex 4 to Article 16 (3) of Ordinance No. PД-02-20-5 on the content, creation, and maintenance of the cadastral map and cadastral registers [105]. Figure 14 illustrates coworking and flexible workspaces located in buildings with the following uses:

• Buildings for Permanent and Temporary Residential Habitation
  • Residential buildings—multi-family—20 pcs.
  • Hotels—2 pcs.
• Public buildings
  • Buildings for the purpose of culture and art—1 pc.
  • Administrative, business buildings—33 pcs.
  • Buildings—monument of cultural heritage—1 pc.
  • Other type of public buildings—1 pc.
• Industrial and storage buildings and buildings for the purposes of infrastructure
  • Buildings for particular purpose—1 pc.
  • Mixed-purpose buildings—7 pcs.

Some of the spaces are located in both old and renovated buildings. Artground Centre [96] is housed in a building from 1926, which is considered cultural heritage. Entract 127 [68] occupies one of the earliest public buildings in Sofia, constructed in the early 1930s to serve as a theatre and hotel. Betahaus Slaveykov Square [72] is located in the former Teachers’ Mutual Savings Bank building, built between 1933 and 1937.

Overtaim Sport Coworking Office [67] presents a unique case, combining sports zones (for basketball, tennis, or football) with coworking spaces. It is situated in the first Bulgarian military school, the Military Academy “G. S. Rakovski”, within a newly constructed multi-purpose sports center. This is not a coincidence but rather a symbolic gesture—the main sports hall occupies the site of the renovated Royal Arena, built in 1892, a cultural heritage monument, alongside the other buildings of the Academy.

Figure 14 shows that the majority of spaces are located in administrative, business buildings. Data from the National Statistical Institute [54] confirm the fact that in recent years, following the COVID-19 pandemic, the number and gross building area of new office buildings in the country have been increasing, as shown in Figure 15 and Figure 16. The majority of these buildings are class A office spaces designed to host coworking and flexible workspaces. In 2023, the number of administrative buildings under construction in Sofia Municipality increased by 40% compared to 2022. Similarly, the gross building area, which was 16,203 sq.m in 2022, grew by 31% to 23,423 m² in 2023. In contrast, among all Bulgarian municipalities with large municipal centers, only Plovdiv experienced an increase (by 62%) compared to the previous two years, rising from 3 to 8 buildings, with the built-up area growing by 77%. The impact of its proximity to the capital is evident.

Information on the category, purpose, main and complementary functions, and limitations of the urban planning zones where the buildings which host working spaces are located is presented in

Table 1. Rules and regulations for urban planning and construction, according to the Urban masterplan of Sofia Municipality [107].

Planning Category	Purpose, Main and Complementary Functions, Limitations
Urbanized areas
Group of residential urban planning zones
Residential zone with high-rise build-up	Predominantly residential zone with buildings exceeding 15 m in height. A change of function to non-residential use is allowed. An underground PG level is required. At least 50% of the greenery zone must consist of tall tree vegetation.
Residential zone with complex build-up	Zones with predominantly complex development. When creating individual regulated land plots for residential buildings within existing residential complexes, the provisions of Article 22 of the Spatial Planning Act must be observed.
Residential zone with medium-rise build-up	Residential zones with build-up up to 15 m. At least 50% of the greenery zone consists of tall tree vegetation.
Residential zone with low-rise build-up under additional specific requirements	The zone covers mainly the former resort districts Gorna Banya, Knyazhevo, Boyana, Dragalevtsi, Simeonovo, and the town of Bankya, for which the minimum area of a regulated land plot is 500 m2 and the minimum face is 16 m.
Central urban planning zone group
Zone of the new business center	The building parameters shall be determined by a Detailed Development Plan and a Working Development Plan prepared on the grounds of the studies of volume and structure, approved by the Sofia City Council.
Zone of the old town center	Mostly in the area of the old town of Sofia.
Central zone with mixed build-up	Mainly in a typical inner city urban environment built with understated parameters.
Group of mixed multifunctional urban planning zones
Mixed multifunctional zone	Mainly for the complexes of the high streets. At least 25% of the greenery zone consists of tall tree vegetation.
Group of urban planning zones for public service activities
Public service activities zone	Mainly for facilities for public services. Buildings with purely residential functions are not allowed. Min 10% of the regulated land plot is high tree vegetation.
Zone for public service activities landscaping in the peri-urban area	Mostly in the peri-urban areas and at the periphery of urban parks. At least 50% of the landscaped area consists of tall tree vegetation.

, an extract from the Annex to Article 3, Paragraph 2 of the Municipality of Sofia Planning and Development Act [106].

Figure 17 shows the distribution of coworking spaces and flexible workspaces in the following urban planning zones:

• Residential zone with complex build-up—3 pcs.
• Residential zone with low-rise build-up under additional specific requirements—1 pc.
• Public service activities zone—1 pc.
• Residential zone with high-rise build-up—4 pcs.
• Zone of the new business center—3 pcs.
• Central zone with mixed build-up—2 pcs.
• Zone for public service activities landscaping in the peri-urban area—2 pcs.
• Residential zone with medium-rise build-up—3 pcs.
• Zone of the old town center—24 pcs.
• Mixed multifunctional zone—23 pcs.

The average rent at the end of October 2024 is presented in EUR in Figure 18. Up-to-date information was collected from the websites of the spaces, and an average price was calculated based on that data. The average price for a daily pass is 30 EUR/day.

4. Discussion

The study of coworking spaces and flexible workspaces in the Sofia Municipality of the Republic of Bulgaria revealed the following features:

• Over the past twelve years, the number of coworking spaces and flexible workspaces in Sofia Municipality has grown significantly, from the first space in both Sofia and the country, Betahaus Bulgaria [72], established in 2012, to 66 locations by the end of October 2024. Currently, local operators outnumber international ones (Figure 6). The favorable business environment and the growth of telecommuting in the capital city have increased the attractiveness of these new workspaces for various types of professionals in need of a collaborative work environment with high-speed fiber-optic internet connectivity to enhance their productivity. In response to the diverse needs of different clients, 86% of all spaces are designed to accommodate all kinds of users. A small number of spaces are specialized (cultural, experiential, digital, psychological) (Figure 7). In their efforts to make the user experience as comfortable as possible, the vast majority of coworking and flex workspaces offer 24/7 access. However, there is also a smaller number of spaces—14% of the total—that are accessible only during standard working hours, Monday to Friday, from 9 a.m. to 5/6 p.m., particularly the specialized ones (Figure 12).
• The growth of coworking spaces and flexible workspaces is also supported by the well-developed transport and communication infrastructure of Sofia Municipality (Figure 5). The public transport network is diverse, offering passengers options such as trolleybuses, trams, city buses, suburban buses, and electric buses [108]. The underground connects the city with Sofia Airport, Terminal 2; Sofia Business Park; most business areas of the capital; the Central Railway Station and Central Bus Station; and the major residential areas [109]. Additionally, some cycling infrastructure has been developed in Sofia, and the city offers a public service for electric scooters. Furthermore, the new buildings housing coworking spaces and flexible workspaces offer parking lots and garages either for free or at preferential prices. In contrast, older buildings nearby typically have parking lots or designated parking spaces.
• The capital also has a well-functioning social, cultural, scientific, and administrative infrastructure that contributes to the development of coworking and flexible workspaces (Figure 5). All spaces are located near medical centers, hospitals, pharmacies, banks, administrative offices, educational institutions, theaters, and cinemas [48].
• In the neighborhoods where coworking and flexible workspaces are located, there are shopping centers, hotels, a variety of independent retail stores, restaurants, and supermarket chains, offering a wide range of goods and services. This abundance of amenities contributes to the increase in the number of spaces. In turn, the available spaces positively impact the growth of local businesses and the sustainable development of the city [48].
• Users of the spaces can combine work with cultural tourism, spa tourism, and sports (Figure 5). Sofia is a city with over 8000 years of history, home to numerous churches, monasteries, and museums. Sofia Municipality is located at the foot of Vitosha Mountain, easily accessible by public transport, and offers diverse recreational activities such as hiking, skiing, mountain biking, and rock climbing. Additionally, there are about 30 mineral springs in Sofia Municipality, which are beneficial for drinking and also offer opportunities for medical treatments, spa experiences, and entertainment. The Bulgarian capital is a green city, with numerous parks and gardens, as well as sports clubs for various sports [55].
• During the study, the hypothesis regarding the influence of the administrative district on coworking spaces and flexible workspaces was confirmed. Although new spaces are emerging in most of the districts of Sofia Municipality, some districts still lack them. This fact can be explained by the difference in the economic activity of enterprises by district, with economic growth being largely concentrated in the central and southern regions of the capital city [55]. The highest number of coworking spaces are found in centrally located administrative districts such as Sredets, Vazrazhdane, and Lozenets, as well as in the Mladost district. In contrast, districts like Lyulin, Krasna Polyana, Nadezhda, Vrabnitsa, Ovcha Kupel, as well as towns near Sofia such as Bankya, Novi Iskar, and former villages like Pancharevo and Kremikovtsi, have predominantly residential functions and, therefore, lack coworking spaces and flexible workspaces (Figure 13).
• The hypothesis regarding the influence of the urban planning zone on coworking spaces and flexible workspaces within it was confirmed. In the outskirts of the city, 38% of the spaces are located between 5 and 9 km from the center, with the majority concentrated in new office spaces within mixed multifunctional zones. In the central city area, 41% of the spaces are located within a 1 km radius from the center and are mainly concentrated in the old town center zone (Figure 4). The operating costs of old office buildings in the city center are lower than those of new buildings, making them suitable for coworking spaces and flexible workspaces. Coworking becomes even more attractive when located in old renovated buildings within the old town center zone, possibly cultural heritage sites. Figure 17 also confirms that these two zones have the highest number of spaces.
• The hypothesis regarding the influence of the building type on the location of coworking spaces and flexible workspaces was also confirmed. The trend shows that larger office buildings hosting coworking spaces and flexible workspaces are increasingly being constructed (Figure 15 and Figure 16). The study indicates that the majority of these spaces (50%) are located in administrative and business buildings; 30% are primarily in smaller spaces located in residential multifamily buildings; and 11% of the spaces are in mixed-purpose buildings (Figure 14).
• Similarly to global trends, coworking spaces and flexible workspaces in Sofia use a fixed rent per workplace, unlike traditional office pricing, which is based on price per square meter (Figure 18). The cost includes meeting rooms, utilities, events, snacks, and soft drinks. One of the key features of the coworking model is that the cost of using the space is offered as a service, with flexible contract terms and various membership options available. These details are provided on each space’s website to meet the diverse needs of business and individual clients. Customization options, such as custom-built workstations and offices in flexible workspaces, are also available.

5. Conclusions

Flexible office spaces and coworking are gaining increasing popularity in Sofia Municipality, Republic of Bulgaria, including as a component of modern office buildings [110,111]. As of the first quarter of 2022, the supply in this segment in Sofia exceeded 45,000 square meters [112], and by mid-2022, it reached 50,000 square meters [113]. At the beginning of 2023, the figure grew to 61,000 square meters [114], and by mid-2023, it reached 63,000 square meters [115]. By the end of the second quarter of 2024, the total volume of coworking spaces reached 68,900 square meters, with an additional 8000 square meters under construction [116].

The findings of this study hold theoretical significance for the field of urban planning, architectural, and urban design. The conclusions could be applied in future strategic and planning documents, within the context of sustainable urban development, and could also serve as a foundation for investment in such spaces. Specifically, they would be useful for making practical decisions by users and owners of coworking and flexible workspaces located in urban environments.

Although this study is limited to the territory of Sofia Municipality, Republic of Bulgaria, its results and conclusions may be applicable or serve as a reference point for future research on similar cities or municipalities.

The study aimed to confirm the hypothesis that the type of urban planning zone, the municipal administrative district, and the designated use of the building housing coworking spaces and flexible workspaces influence their presence and development. This influence was confirmed during the course of the study. Moreover, these findings justify further refinement of the research.

In the next phase, the territorial scope of the study will be expanded to include spaces located in other Bulgarian cities that are smaller in both area and population compared to the capital. This expansion will provide a more comprehensive understanding of the subject matter. Additionally, the research methodology will be enhanced and refined by integrating qualitative research methods, which will enrich the findings and contribute to achieving the study’s objectives.