1. Introduction
The development of civilizations and cities over the centuries has been determined by energy consumption. In the world’s most developed countries, we observe higher per capita energy consumption than in less developed countries [
1].
It is difficult to assume that developed countries will be able to reduce this consumption without compromising quality of life. Energy demand will increase with increasing technological development, leading to the development of renewable energy production.
Local spatial planning acts (i.e., local spatial development plans, general plans, studies of the conditions and directions of the spatial development of the municipalities), national law (acts and regulations), and European Union regulations (directives of the European Parliament and the Council) regarding sustainable development and energy efficiency should be tailored to local circumstances, not global ones. This approach is necessary because European countries differ significantly in terms of climate, landscape, resource availability, and potential for generating energy from renewable sources. To illustrate this, in this study, we conducted research in municipalities in Poznan County and assessed the area against specific criteria. We weighted these criteria based on expert assessment, assessment based on global EU regulations, and assessment based on Polish and local law to compare them and demonstrate that the results differ. The legal regulations referred to have been detailed in
Section 3 (Materials and Methods) and
Section 3.1 (Research Material).
The problem pertaining to communes around Poznan is uncontrolled urban sprawl [
2], which results in a suboptimal spatial distribution of functions. As a result, services important for inhabitants, which influence quality of life, are not provided [
3]. The problems include a lack of commercial services, educational institutions, workplaces, and recreation and leisure areas within an accessible range, necessitating commuting to such facilities [
4]. Dispersed development, along with insufficient transportation infrastructure and low accessibility of public transport, hinders traffic access. This leads to waste of time, energy losses, and higher fuel consumption for commuting [
5]. All these issues influence the social needs of inhabitants, which is why they should be considered in commune governance. Furthermore, these factors have ecological significance for energy consumption, quality of air, water resources, biodiversity, etc. Therefore, concern for the proper development of the commune and sustainable development is in line with global trends and sustainable development goals. The factors mentioned above relate to sustainable development adapted to local conditions [
6]; therefore, they were assessed in this study.
Taking all of the above into account, we observed that problems and conditions are so individual and territorially diverse that adapting solutions to sustainable development goals requires taking these differences into account in legislative documents and development planning. Therefore, this article examines how the same criteria are weighted depending on whether global or local regulations are applied. To support this analysis, rankings based on selected municipalities in the Poznan district are presented. The main research objective is to demonstrate the disparities between local and global approaches to formulating sustainability and energy efficiency requirements for municipalities, and subsequently to identify areas that require improvement in this regard.
In this study, communes in Poznan County were ranked by energy efficiency [
7], to be able to assess which areas of sustainable development are insufficiently taken into account in individual municipalities, and which should be strengthened. The criteria on which the ranking was based refer to matters of transportation, function, energy efficiency, buildings, greenery, and social participation. We used QGIS software (version 3.40.7 Bratislava) for data collection [
8] and the AHP multi-criteria decision analysis method for the assessment. We involved architecture students and gathered data on their rural practices to assess the actual situation in 17 communes around the city of Poznan. This research may be helpful in decision making about the locations of future investments in municipalities. The data obtained about the commune are assessed according to selected criteria; however, the weights of these criteria may differ depending on which type of legal regulations they were based at the time of assessment: global or local. This means that rankings for the same municipality may differ despite using the same criteria during evaluation, depending on the regulations on which the assessment is based: global or local.
The entire study is described in detail in the following chapters.
Section 2 presents the state of the art, taking into account contemporary ideas in urban planning, particularly those related to suburban areas, the impact of urban design on energy efficiency and sustainability, and a review of similar studies to date.
Section 3 provides a detailed description of the research material—17 municipalities located in the suburban area of Poznan, along with data sources and methods of data collection, and the methodology applied—specifically, the use of the AHP method in four scenarios: local conditions assessed by experts, local spatial planning regulations, Polish law, and European Union regulations assessed using AI tools. The results, including the hierarchy of sustainable development and energy efficiency criteria across the four scenarios, as well as rankings of the municipalities according to each scenario, are presented in
Section 4.
Section 5 includes the discussion: it addresses the limitations and shortcomings of the presented study, interprets the results, and proposes directions for future research.
3. Materials and Methods
3.1. Research Material
As research material, several datasets related to various aspects of development in the municipalities in Poznan County were used. Poznan County contains 17 municipalities, including 7 rural municipalities, 8 mixed urban–rural municipalities, and 2 urban municipalities (containing only single towns). In order to make them comparable, urban municipalities were merged for statistical purposes with neighboring rural or urban–rural municipalities. As a result, for the purposes of comparison, 15 statistical units (
Figure 1) were created:
Buk (urban–rural municipality);
Czerwonak (rural municipality);
Dopiewo (rural municipality);
Kleszczewo (rural municipality);
Komorniki (rural municipality) + Luboń (urban municipality);
Kostrzyn (urban–rural municipality);
Kórnik (urban–rural municipality);
Mosina (urban–rural municipality) + Puszczykowo (urban municipality);
Murowana Goślina (urban–rural municipality);
Pobiedziska (urban–rural municipality);
Rokietnica (rural municipality);
Stęszew (urban–rural municipality);
Suchy Las (rural municipality);
Swarzędz (urban–rural municipality);
Tarnowo Podgórne (rural municipality).
The research material consists of data collected during student summer rural practices in the academic year 2023/2024 on the location of basic services in the municipalities of Poznan County. These data were used to assess several criteria and were collected in two forms:
Other spatial data available from the spatial information systems of the municipalities and Poznan County were additionally used in this research, in particular:
Land and building records;
The road network;
The public transport network;
The designation of areas for residential and service functions in local spatial development plans, and a study of the conditions and directions of the spatial development of municipalities.
Spatial data on the actual use of areas for residential and service functions was obtained from, among other work, studies carried out as part of student summer rural practices in the academic year 2020/2021 (
Figure 3).
Data about building energy efficiency were collected from the central energy certificate records (Centralny rejestr charakterystyki energetycznej budynków,
https://rejestrcheb.mrit.gov.pl, accessed on 1 November 2024).
Community participation and governance: Data for the assessment under this criterion were obtained from the municipality’s website and directly during telephone conversations with the municipal office, consisting of verifying whether participatory budgets are provided for each municipality and whether the community submits projects. The research covers the previous budget period for the year 2024/2025.
Pollution reduction strategies: To evaluate municipalities based on pollution reduction strategy criteria, data collected throughout the year from air quality monitoring stations in individual municipalities were compiled. Air quality data were collected from the website of the Chief Inspectorate of Environmental Protection (Air Quality Assessment—Current Measurement Data—GIOŚ (Chief Inspectorate of Environmental Protection) and [
https://aqicn.org/map/poznan/pl, accessed on 1 November 2024]). The research covers the period for the year 2024.
Data about transportation network/public transport accessibility were collected from GUS—Central Statistical Office (Główny Urząd Statystyczny).
Data about urban density were collected from spatial databases of the land and building records of Poznan County.
AI was used to assess EU regulations, Polish law and standards, and local law using certain documents. The first assessment was made by artificial intelligence based on the following Key EU Documents: European Green Deal (COM/2019/640); EU Energy Efficiency Directive (2012/27/EU, amended 2023); EU Taxonomy Regulation (EU 2020/852); Renewable Energy Directive (RED III) (2023/2413); Fit for 55 package; Urban Agenda for the EU; New European Bauhaus; Smart Cities Marketplace; EU Biodiversity Strategy 2030. The second assessment was made by artificial intelligence based on Polish law (KPEiK—Polish National Energy and Climate Plan 2021–2030; Krajowa Polityka Miejska 2030—National Urban Policy 2030; PEP2040—Energy policy of Poland until 2040; Prawo ochrony srodowiska—Environmental Protection Law; Act on Electromobility and Alternative Fuels; Strategy for Sustainable Development of Transport 2030; Act on Spatial Planning and Development; Strategi Zrównoważonego Rozwoju Energetycznego—Climate Policy of Poland). The third assessment was based on the Local Law of the City of Poznań—BIP resolutions (
https://bip.poznan.pl/bip/uchwaly/; https://
www.poznan.pl/mim/main/-,p,22550,22551,22560.html, accessed on 8 November 2024).
3.2. Research Methods
The energy efficiency of the municipalities was assessed in a multi-criteria fashion using the AHP (Analytic Hierarchy Process) method (AHP Decision for Mac version 1.1.0 Apple software) (
Figure 4).
Nine criteria were selected to assess the energy efficiency of municipalities as part of sustainable development. These criteria were established based on an analysis of the most frequently appearing keywords in 1000 scientific articles on the topic of sustainable development, regarding criteria related to urban planning that influence energy efficiency in communes, searched using the Scopus AI tool. The received issues were grouped into the following nine criteria:
- K1.
Public transport accessibility;
- K2.
Mixed use development;
- K3.
Green space;
- K4.
Building energy efficiency;
- K5.
Urban density and compact design;
- K6.
Renewable energy integration;
- K7.
Smart technology;
- K8.
Community participation and governance;
- K9.
Pollution reduction strategies.
Data on the individual criteria for each municipality were calculated and collected as follows:
K1. Public transport accessibility. Data were collected from GUS—Central Statistical Office (Główny Urząd Statystyczny). The evaluation was based on the number of bus stops per resident in the given municipality, using data from 2018–2024.
K2. Mixed Use Development and K7. Smart Technology. The study covered selected services provided in the Poznan Region, divided into individual municipalities. The services were isolated from a set of 223 types, which were grouped according to individual categories: religion; health and medicine; basic commercial services; basic services; mixed commercial services; creative services; banking services; automotive services; cultural, sports, accommodation, official, gastronomic, school, agricultural, social, and industrial services. In order to identify the number and location of a given service in the specific municipality, an inventory of the area was made using geolocation on the map. The study used geolocation data from the Google Maps portal, which was verified through walk-through surveys of individual municipalities. A total of 120 students in the sixth semester of Architecture at Poznan University of Technology took part in collecting data on the location of functions in Poznan district. The data were collected in July 2024. The collected data were placed in a table, which was used to develop numerical data—in particular, a numerical breakdown of all services in a given category with each of the municipalities of the county. The resulting database of 8786 services, together with geolocation data, was used to create maps of spatial data in the QGIS program. The service figures were used to determine the energy-saving-city indicators in the categories K2—Mixed Use Development and K7—Smart Technology. The figures for K2 and K7 for each of the municipalities were summarized, and then, the formula was used to normalize the min–max values.
K3. Green Space. Data collected in July 2021 by students in the sixth semester of Architecture at Poznan University of Technology were used to calculate the K3 index. Information on the size of green areas and the number of inhabitants was collected for a given municipality. Data on the size of green areas per inhabitant were obtained. The received data were normalized, thus obtaining the expected index.
K4. Building energy efficiency. Building energy efficiency was assessed based on data from the Central Register of Energy Performance of Buildings (pol. Centralny rejestr charakterystyki energetycznej budynków,
https://rejestrcheb.mrit.gov.pl, accessed on 1 November 2024), access date 1 November 2024—the certificates available to date covered 15.48% of existing buildings, including mandatory certificates for all buildings newly commissioned after 28 April 2023. The register contains data on all the energy performance certificates of buildings in Poland. An energy performance certificate is a document specifying the energy performance of an existing or commissioned building, i.e., a set of data and energy indicators of a building or part of a building, specifying the total energy demand necessary for its intended use. The certificate contains values of the annual demand for usable energy, final energy, and non-renewable primary energy, as well as the unit CO
2 emissions and share of renewable energy sources in the annual demand for final energy.
For comparison, the index of annual demand for non-renewable primary energy EP [kWh/(m2 × year)] was chosen. The primary energy index was calculated according to the methodology included in the Polish Regulation of the Minister of Infrastructure and Development on the methodology for determining the energy performance of a building or part of a building and energy performance certificates.
K5. Urban density and compact design. Data about urban density were collected from spatial databases of land and building records of Poznan County (Powiat poznański—System Informacji Przestrzennej,
https://poznanski.e-mapa.net/, accessed on 8 November 2024). The urban density index was calculated for the geographical unit of reference defined by a square grid of 500 × 500 m as a ratio of built-up area to land area.
where
is the urban density index;
is the total built-up area of all buildings in a unit of reference;
is the land area of a unit of reference.
The compact design is related to the distribution of the development. Built-up areas may be concentrated or evenly distributed within the commune area. The more concentrated the distribution of buildings, the higher the index of compact design in the commune. The compactness of the building can be calculated as a measure of uneven distribution. For this purpose, the Gini coefficient was used as a measure of the compactness of development in each commune:
where
is the Gini coefficient of the distribution of buildings in a given commune;
is the value of the urban density index in the i-th geographical unit of reference;
is the total number of geographical units of reference in a given commune;
is the average value of the urban density index in a given commune:
K6. Renewable energy integration. Renewable energy integration was evaluated based on data taken from the Central Register of Energy Performance of Buildings, regarding the share of renewable energy sources UOZE [%] in the annual demand for final energy EK [kWh/(m2 × year)].
K7. Smart technology. Information about the intensity of the use of smart technologies in individual municipalities was collected during rural student practices in July 2024 and measured based on the number of creative industry and smart technology institutions present.
K8. Community Participation and governance. The most important parameter within the Community Participation and Governance criterion is considered to be the engagement of local communities in bottom-up actions aimed at improving the quality of life of residents. The main activity that enables such bottom-up actions is the submission of projects by residents to the civic budget as part of a competition within a single municipality. Data for the assessment of the commune under this criterion were obtained from the municipality’s website and directly during telephone conversations with the municipal office, consisting of verifying whether participatory budgets are provided for each municipality and whether the community submits projects. The research covers the previous budget period for the year 2024/2025.
K9. Pollution reduction strategies. To evaluate municipalities based on pollution reduction strategy criteria, data collected throughout the year at air quality monitoring stations in individual municipalities were compiled. Air quality data were collected from the website of the Chief Inspectorate of Environmental Protection (Air Quality Assessment—Current Measurement Data—GIOŚ (Chief Inspectorate of Environmental Protection) and [
https://aqicn.org/map/poznan/pl]). The research covers the period for the year 2024.
Data normalization. In order to make different criteria comparable, all values were converted into ratings normalized to the range [0, 1], where 1 is the most advantageous rating among all considered items and 0 is the least advantageous.
The formula for the values that should be maximized in order to achieve the best rating is as follows:
where
is the normalized rating of the i-th item;
is the value of the parameter of the i-th item;
is the lowest value of the parameter among all items;
is the highest value of the parameter among all items.
The formula for the values that should be minimized in order to achieve the best rating is as follows:
where
is the normalized rating of the i-th item;
is the value of the parameter of the i-th item;
is the lowest value of the parameter among all items;
is the highest value of the parameter among all items.
4. Results
In order to assign weights to individual criteria, a five-person expert group compared the importance of these criteria in pairs (on a scale of 1–9) using the AHP method (
Table 1). The correlation coefficient for this assessment was 9%. The expert group included four architects and urban planners who are scientists in the field of engineering and technical sciences with architectural and construction licenses to design without restrictions. One of them has experience working in the Municipal Urban Planning Studio. The fifth expert is a second-cycle student of the Faculty of Architecture in Poznan University of Technology. The presence of experts from only a single field of science constitutes a certain limitation. Our recommendation for future research would be to assemble experts from as wide a range of technical fields as possible, as well as from the natural and social sciences.
In order to be able to compare the expert assessment, ChatGPT (version GPT-4o mini) artificial intelligence was used to assign weights to the nine selected criteria based on, first, the local laws of the city of Poznan (
Table 2); second, Polish law regulations and norms (
Table 3); and, third, EU Regulations (
Table 4).
First, the following prompt was used: “make pairwise comparison matrix using AHP method, calculate correlation coefficient (must be <10%), calculate weights. Doing this, take into consideration the Local Law of the City of Poznan—BIP resolutions, regarding sustainable development and energy efficiency.”
Second, in order to be able to compare the expert assessment, ChatGPT artificial intelligence was also used to assign weights to the nine selected criteria based on Polish law. The following prompt was used: “make pairwise comparison matrix using AHP method, calculate correlation coefficient (<10%), calculate weights, based on local law, Polish Government regulations regarding sustainable development and energy efficiency.” The second assessment was made by artificial intelligence based on Polish law (KPEiK—Polish National Energy and Climate Plan 2021–2030; Krajowa Polityka Miejska 2030—National Urban Policy 2030; PEP2040—Energy policy of Poland until 2040; Prawo ochrony srodowiska—Environmental Protection Law; Act on Electromobility and Alternative Fuels; Strategy for Sustainable Development of Transport 2030; Act on Spatial Planning and Development; Strategi Zrównoważonego Rozwoju Energetycznego—Climate Policy of Poland).
Third, the following prompt was used: “make a pairwise comparison matrix using the AHP method, calculate correlation coefficient (must be <10%), calculate weights. Doing this, take into consideration EU regulations regarding sustainable development and energy efficiency.” An assessment was made by artificial intelligence based on the following Key EU Documents: European Green Deal (COM/2019/640); EU Energy Efficiency Directive (2012/27/EU, amended 2023); EU Taxonomy Regulation (EU 2020/852); Renewable Energy Directive (RED III) (2023/2413); Fit for 55 package; Urban Agenda for the EU; New European Bauhaus; Smart Cities Marketplace; EU Biodiversity Strategy 2030.
From these, we prioritize:
Energy efficiency (K4) and renewable energy (K6) very highly;
Public transport (K1), pollution reduction (K9), and compact design (K5) highly;
Green space (K3), smart technology (K7), and community governance (K8) moderately highly;
Mixed use (K2) moderately, based on urban planning goals.
For each assessment, a consistency check was performed to ensure the logical coherency of pairwise comparisons of the criteria following the standard procedure defined within the AHP methodology [
69]. The consistency ratio is calculated according to the following formula:
where
In this formula, the consistency index is calculated as follows:
where
The maximum eigenvalue of the matrix is defined by the following formula:
where
The criteria weighting values according to all four assessments discussed are presented in the table below (
Table 5).
The presented rankings of the criteria according to four scenarios were validated by calculating Kendall’s W coefficient and Spearman’s rank correlation coefficient (ρ). The Kendall’s W coefficient value of 0.43 indicates a moderate level of agreement between the assessments provided by the expert panel and the AI models analyzing regulations on three levels. A more detailed insight into the discrepancies between assessments is provided by Spearman’s rank correlation coefficient (
Table 6).
The weights obtained for the criteria, from the expert assessment and three assessments made by artificial intelligence, were used to rank communes using the AHP method (
Table 7). This shows how the assessment differs depending on the regulations adopted in the evaluation.
The differences in weighted values between rural and urban–rural municipalities are minor across all assessment approaches, likely because both types often represent suburban areas with similar spatial structures and development issues, despite their formal administrative distinctions. The combined units that include fully urban municipalities, however, reveal noticeably lower scores, which may result from the limited availability of extensive areas for new suburban housing development and the more compact spatial structure of towns like Luboń and Puszczykowo.
5. Discussion
The research conducted aimed to verify whether provisions in local, national, and European legal regulations differ.
However, several limitations were encountered that may have influenced the research outcomes. These limitations were related to two main areas: data availability and the composition of the expert group. Regarding data availability, the scope and format of data publication varied significantly between municipalities. Moreover, the available datasets were limited in both temporal and territorial coverage. Not all municipalities possessed a complete set of records. Filling these gaps would have required supplementary data collection beyond the accessible datasets and the planned research framework. This would have exceeded the foreseen time constraints and significantly delayed the publication of results, potentially rendering them outdated. Therefore, it was decided to base the analysis on a dataset restricted to available information. The second limitation, concerning the composition of the expert group, was that its members had knowledge and experience mainly in the fields of urban planning and architecture. Future research is expected to expand this group to include experts from other relevant fields.
Kendall’s W coefficient and Spearman’s rank correlation coefficient are calculated in
Section 4. The results indicate that there are significant discrepancies between the factors regarding energy efficiency and sustainable development, taking into consideration regulations on local, national, and supranational levels. While the EU and Polish legal systems are more or less coherent, the local regulations do not correspond with them, as the negative value of the correlation coefficient shows.
This result confirms the belief that local law should be adapted to the local conditions of the commune. A prime example is the urbanization of mountainous areas, which differs significantly from the urbanization processes in the plains. For example, the mountainous landscape contributes to depopulation (and the aging of communities) in these areas [
48]. However, the suburban municipalities studied require a different approach, partly because they face different challenges, including demographic, landscape, economic, and other issues. They are experiencing mass migration from cities (urban sprawl). They are also experiencing a shift from agricultural to residential and service character (declining agricultural employment), as in rural areas, but on a much larger scale [
70,
71].
From the ranking of weights in expert assessment based on local conditions and assessment made by AI (ChatGPT) based on Polish law regulations and norms, EU regulations result in a situation in which the most important criterion influencing sustainable development of the commune is Renewable Energy Integration. The situation is different in the case of AI assessment based on the local law acts of the Poznan district. The low position of the Renewable Energy Integration criterion in the assessment made by AI based on the local law acts of the Poznan district reflects the actual state of affairs in the provisions of local law. Limited reference to renewable energy sources in the General Plans of municipalities can be observed (they are referenced only in one of the zones—the open zone—with wind and solar power plants as a basic/supplementary profile) [
72]. There are no or few regulations regarding renewable energy sources in most local spatial development plans for residential and commercial areas.
Another observation after analyzing the results is that the mixed-use development criterion is generally considered a low priority under EU, Polish, and local law. However, according to expert assessments, this matter should be given more focus. This issue is addressed in contemporary urban planning ideas (15 min city, new urbanism, etc.), but it is not included in the spatial planning legislation, which is still based on zoning. Urban density and compact design are also insufficiently considered in local law [
73,
74].
Biodiversity appears to be a relatively important issue in local law. Indeed, there are many restrictions on investments and their processing resulting from the protection of valuable natural sites and species (Natura 2000, environmental decisions, etc.). Such provisions can be interpreted as an opportunity to protect areas of natural value; at the same time, restrictive procedures for obtaining building permits may block or delay certain investments that may improve transport or energy efficiency, for example.
The comparison of criteria weights indicates that bottom-up initiatives, crucial in shaping fourth-generation cities that respond to user needs, are not included in the EU Regulations or Polish law, and experts regard these a significant element in shaping the sustainable development of municipalities or energy efficiency. However, its importance was recognized in local law.
The ranking of spatial units presented in this study serves an illustrative purpose and demonstrates how the adopted method determines the final results. The weights and hierarchy of criteria, as well as the observed differences between the global and local approaches, are strictly dependent on the local context and therefore cannot be directly generalized. Applying the proposed framework in different locations may lead to different results, which is why the entire evaluation procedure should be carried out individually for each given area, taking into account its specific characteristics.
The methods, research, and conclusions drawn from the results used in this article can be used by municipal authorities to make decisions about spatial development or which areas require improvement. What are the municipalities’ needs regarding spatial planning and sustainable development? Where should specific functions and investments be located?
Therefore, the conclusions from the conducted research emphasize the need for greater territorial differentiation and adaptation of planning regulations to local realities—at both the national and EU levels. Legal frameworks and spatial policies should consider local and regional specificities, including climatic conditions, physiographic features, socioeconomic structure, demographic trends, cultural landscape, and the availability of natural and infrastructural resources. Recognizing and integrating these factors would enable more informed, flexible, and sustainable planning decisions—particularly in dynamically changing suburban municipalities, facing challenges such as migration (i.e., to the peri-urban zone from city centers), land-use transformation, infrastructure shortages, and environmental pressures. In this context, the presented study provides not only an analytical basis for assessing current planning practices but also strategic guidance for shaping more resilient and locally adapted spatial development policies.
The research will be continued and extended in several directions. The primary goal is to address current limitations by involving experts from diverse fields related to sustainable development, such as environmental engineering, energy, social studies, spatial management, environmental protection, hydrology, and others, with the aim of comparing and validating results across disciplines. Further research directions include studies of the accessibility of services in relation to the planning of newly developed residential areas, using isochrone-based analyses, considering environmental impact.