This article explores how light distribution affects classroom environments and highlights its potential as a design parameter. While lighting intensity and spectrum have been widely studied due to recent technological advances, light distribution from children's vantage points has rarely been addressed. The study includes a survey of current classrooms, a review of school lighting guidelines and a pilot study exploring various lighting scenarios. Observations from six schools are summarized through sketches, followed by the development of six light distribution schemes at the children's desks. These schemes are evaluated using illuminance measurements and photo documentation and compared with software simulations (Dialux Evo 12). One outcome, relevant when designing for children, showed higher vertical illuminance for 1.00 m eye height than 1.20 m for the same horizontal illuminance under directional light. The results outlined the definition of six lighting scenes, achievable using one lighting system, to inform a field study on classroom lighting.

Objectives: This study examines how different lighting scenarios, involving variations in intensity and/or colour, influence safety perceptions on metro station platforms and in passages.

Methods: Physical filters were applied to the station’s lighting to create different scenarios, which were compared to baseline conditions using MANOVA, correlation, and regression models. The experiment involved 92 participants—67 university students and 25 older individuals with visual impairments. After informed consent and a visual performance assessment, participants experienced each lighting condition in two sequences, including wash-outs.

Results: “Safety” is associated with “comfort” and “pleasantness” and less with “colour” related emotional responses. On platforms, dimmed neutral lighting does not lower safety perceptions compared to the neutral baseline. In passages, the reduction in safety scores under treated lighting passages remains significant even after controlling for participants’ gender, crime exposure, disabilities, and test order. Participants with visual impairments consistently reported lower perceived safety, particularly in passages with reduced, coloured lighting. The study underscores the importance of inclusive lighting design and calls for further experimental CPTED research on minimum lighting thresholds, emphasising the need to disentangle the effects of colour from intensity when assessing lighting’s impact on safety.

This report investigates the photometric performance and energy consumption of four electric lighting alternatives for classrooms, aiming to identify energy-efficient and visually effective solutions for educational environments. Conducted within the framework of the LiSE (Lighting in School Environments) research project, the study compares traditional fluorescent tube pendants (Alt. 1) with three LED-based systems: retrofit LED tubes (Alt. 2), 60x60 cm LED panels (Alt. 3), and advanced LED pendants with controllable spotlight scenes (Alt. 4). Simulations were performed using Dialux Evo 11.1 software, based on real classroom conditions in a Swedish school, following the EN 12464-1:2021 lighting standards. Results show that all LED alternatives reduce annual energy consumption, with Alt. 3, achieving the highest savings (63%) and Alt. 4 offering adaptable lighting scenarios to support varied teaching activities. The study highlights the importance of integrating lighting controls and user-centered design to enhance visual comfort, energy efficiency, and functional flexibility in learning spaces.

Urbanisation is leading to an increase in outdoor lighting technologies in cities, which can disrupt wildlife habitats in urban greenery and alter their natural biological, physiological, and behavioural rhythms. Despite the flexibility of LED lighting technology, it is not being used effectively in practise to minimise ecological disturbances while providing sufficient illumination for people. A PRISMA review of 31 papers on lighting using contemporary LED sources and wildlife species revealed that lighting parameters were inadequately described to (1) characterise the relationship between assessed ecological impacts and light properties and (2) adjust properties of contemporary lighting technologies to reduce such impacts on animals. The authors suggest strengthening interdisciplinary collaborations for informed sustainable development by establishing common procedures and methods to ensure the transferability of research outcomes to practical applications.

This is the third part of a three-part technical report about the Uppsala testbed part of the NorDark research project. The earlier two reports contain the corresponding information based on the existing outdoor lighting installed at the testbed site in Sävja, Uppsala (Dincel, 2023; Dincel, 2024). Part One discussed the method and procedure of collecting data as well as illuminance and luminance levels by hand-held and HOBO sensor devices under different sky and weather conditions. Part Two complemented the first part by including spectral power distribution (SPD) and correlated colour temperature (CCT) values of the same conditions recorded by hand-held spectrometer devices and wearable LYS button sensors. This part focuses on outlining the measured results of illuminance and spectral properties after an outdoor lighting intervention was implemented at the site. The post-intervention measurements described here were conducted on specific days within a timeframe during the period of November 2023 and January 2025.

Reducing light pollution and promoting sustainable lighting practices require new tools that integrate environmental, social, and technical considerations in design processes. Urban Digital Twins are emerging as powerful instruments for this purpose, enabling integrated evaluation of lighting impacts on both people and ecosystems. This paper presents an exploratory evaluation of NorDark-DT, a recently developed urban digital twin designed to support the sustainable planning of lighting infrastructure in green urban areas. This exploratory assessment was conducted with master’s students engaged in lighting design practices. Participants performed two task-oriented exercises of planning and comparing lighting configurations after-dark for a site in Uppsala, Sweden. Results show that NorDark-DT effectively facilitates the exploration of alternative lighting solutions within realistic green urban area contexts and encourages reflection on issues such as light pollution, biodiversity, and ecological preservation. Nevertheless, further improvements are required to enhance the user interface, expand analytical capabilities, strengthen integration with professional lighting software, and optimize performance for varying hardware setups. Beyond professional practice, the tool also proved valuable for educational purposes by promoting interdisciplinary collaboration and broadening students’ understanding of sustainability in lighting design. Overall, this study provides an initial step in a usability assessment of NorDark-DT, confirming its potential to support environmentally responsible, socially aware, and well-informed lighting interventions.

The prevailing implementation and usage of contemporary lighting technologies and design practices in cities have created over-illuminated built environments. Recent studies indicate that exposure to electric lighting effects formed through spatial characteristics has visual, physiological, and behavioural effects on both humans and non-humans, such as wildlife. In order to gain a better understanding of the impact that electric lighting has on space and different organism groups, a comprehensive literature review was conducted applying PRISMA 2020 systematic review guidelines. Results of the searches from various databases, such as Web of Science, PubMed and Scopus, identified 5260 related studies. A total of 55 papers connected to four themes: (1) urban morphology; (2) human visual impressions; (3) ecological impacts; and (4) design approaches and methods were analysed with a focus on urban morphology. The review provided the following general findings: lighting properties alone are inadequate to depict visual impressions of pedestrians, patterns formed through light interacting with spatial characteristics can contribute to understanding how spaces are visually perceived and help characterising the exposure of wildlife organisms to potential disturbances.

Att investera i ett tryggt kollektivtrafiksystem innebär att främja tillgänglighet som en grundlägganderättighet för alla. Ljusförhållanden är avgörande för att göra kollektivtrafik tillgänglig, eftersom depåverkar en individernas syn och upplevelse av trygghet. Dock saknar vi fortfarande en djupareförståelse för hur ljusförhållanden, dvs belysningen på en plats, påverkar individuell trygghet påoffentliga platser som tunnelbanestationer. Denna studie undersöker belysningens påverkan påindividuell uppfattning av trygghet på två olika stationstyper: plattformar och passager. Studien fokuserarpå förändringar i ljusförhållanden (intensitet och färg) genom experiment vid Fridhemsplanstunnelbanestation i Stockholm samt i virtuella verklighetsscenarier (VR-scenarier) som speglar denverkliga stationen. Basscenarier jämförs med två alternativa ljusscenarier, och 92 deltagare deltog iexperimentet—67 universitetsstudenter och 25 äldre personer med synnedsättning—i både stationsochVR-miljöerna. Resultaten visar att ljusets färg påverkar trygghetsupplevelsen negativt, där blått ochorange ljus resulterade i lägre upplevd trygghet jämfört med Basscenarierna där ljuset var vitt. Någotintressant är att dämpat ljus (reducerat med 39%) på plattformen inte hade någon signifikant påverkanpå trygghetsupplevelsen i stationsexperimentet. Deltagarna tenderade att associera högre värden tillordet ’trygghet’ än till ’säkerhet’ vid frågorna under identiska ljusförhållanden. I kontrast bedömdestrygghet och säkerhet i passager generellt lägre än på plattformarna. Trygghet och säkerhet relateradesoftare till faktorer som komfort, bekvämlighet, ljusstyrka och öppenhet, snarare än till färg eller värme ibåde stations- och VR-experimenten. I VR-modellen påverkades upplevelsen av trygghet mer avindividuella faktorer (t.ex. synnedsättning eller tidigare erfarenheter som brottsoffer) än istationsexperimentet. Trots dessa skillnader var resultaten från både VR- och fältexperiment överlagöverensstämmande, där deltagarna noterade större skillnader mellan ljusscenarierna i VR än påstationen. Plattformens trygghet bedömdes som högre i VR än i stationen, medan passager upplevdessom tryggare i stationen än i VR-miljön. Ytterligare analyser krävs för att bättre förstå de potentiellasambanden mellan VR-resultaten och resultaten från fältexperimentet. Ett viktigt resultat är att personermed synnedsättning rapporterade lägre trygghetsupplevelse i alla scenarier än de utan synnedsättning,vilket understryker vikten av att beakta belysning som en central tillgänglighetsfråga för personer medsynnedsättning i tunnelbana. Ett annat viktigt fynd är att dämpat ljus på plattformen inte påverkadedeltagarnas uppfattning om trygghet. Detta tyder på att lägre belysningsnivåer (i vårt fall: 110 lux pågolvet, med en max luminans på 600 cd/m2, i neutralt vitt ljus på 4000 Kelvin1) kan användas för attspara energi på stationer med liknande plattformdesign utan att avsevärt påverka resenärernasupplevda trygghet. Det är nödvändigt att i framtida studier undersöka tröskelnivåerna för belysningtillsammans ljusfördelning (kontrast, reflektivitet, perspektiv) för att säkerställa att ljusförhållandenafungerar för alla typer av resenärer, inklusive de med synnedsättning. Rapporten avslutas medytterligare rekommendationer för forskning och praktisk tillämpning, inklusive med användning av VRscenarier.

Investing in a safe public transport system means promoting accessibility as a fundamental right for allcity users. Lighting conditions are crucial in making public transportation accessible to everyone, as theyimpact an individual’s vision and safety perceptions. However, a deeper understanding of how lightingconditions (illumination in a particular place) affect an individual’s safety perceptions in subway stationsis still lacking. This study examines the effect of lighting on passengers' safety perceptions in two distinctstation environments: platforms and passages. The research focuses on changes in lighting conditions(intensity and colour) through experiments conducted at Fridhemsplan station in Stockholm, Sweden,and in virtual reality (VR) scenarios that mirrored the actual station. Baseline scenarios are comparedwith two alternative lighting scenarios, with 92 participants involved in the experiment—67 universitystudents and 25 elderly individuals with visual impairments—participating in the station and VRenvironments. The results show that the colour of the light negatively affects the perception of safety,with blue and orange light resulting in lower perceived safety compared to the baseline scenarios. Moreinterestingly, dimmed light (reduced by 39%) on the platform did not significantly impact safetyperception in the station experiment. Participants generally associated higher scores with the word'safety' than 'security' when prompted with questions under identical lighting conditions. In contrast,safety and security in passages were generally rated lower scores than in platform scenarios. Safetyand security were more frequently linked to factors such as comfort, convenience, brightness, andopenness rather than colour or warmth in the station and VR experiments. In the VR model, safetyperception was more influenced by individual factors (e.g., visual impairments or prior experiences ascrime victims) than in the station experiment. Despite these differences, the results from VR and fieldexperiments in the station were generally aligned, showing a strong correlation. Participants noted morepronounced differences in the lighting scenarios within the VR environment compared to the station.Platform safety was rated higher in VR than in the station, whereas passages were perceived as saferin the station than in the VR environment. Further analysis is needed to better understand the potentialconnections between the VR results and those from the field experiment. An important finding is thatpeople with visual impairments reported lower safety perceptions across all scenarios than those withoutimpairments (including in the VR experiment), emphasizing the need to consider lighting as a keyaccessibility issue for individuals with visual impairments in public transport. Another key finding is thatdimmed light on the platform did not significantly affect participants' safety perceptions compared to thebaseline lighting conditions. This suggests that lower lighting levels (in our case: 110 lux on the floor,with max luminance of 600 cd/m2, in neutral white light of 4000 K2) could be used in similar platforms tosave energy in stations without significantly affecting passengers’ safety perceptions. Future studiesmust examine lighting threshold levels together with distribution (contrast, reflection, view angle) toensure lighting conditions work for all passengers, including those with visual impairments. The reportconcludes with further recommendations for research and practice, including pilot tests in VR.

This paper explores the use of participatory methods prior to designing interventions within a research project at a primary school in central Sweden. The approach presented in the paper is based on the principles of participatory design (PD), to enhance the use of these methods within the areas of educational research (ER), lighting, and architecture. This approach aims to include participants of educational spaces and incorporate their views prior to design interventions. Two workshops were designed to support teachers' participation through hands-on activities. Twenty-eight teachers participated in the workshops. Scale models corresponding to two of the school's classrooms were used to initiate discussions regarding the interconnection between spatial layouts, lighting, and learning activities. The workshops' data collection analysis assisted the research group in understanding the school's spatial and learning characteristics. The information gathered from the workshops provided additional knowledge and informed the research project in a way that allowed for further development and changes within the project related to the additional variables measured along with light. According to the analysis, there is a correlation between the activity and the desired layout of the space, while the type of equipment also varies according to the task. 

This is the second part of a technical report related to the NorDark research project complementing the information in report part one that was published previously (Dincel, 2023). This document outlines the spectral properties of the measured results, such as the spectral power distribution (SPD) and related metrics, for example, the correlated colour temperature (CCT). The measurements were conducted in Sävja, Uppsala, for a specific day and timeframe during the period of November 2022 and February2023. In the first part of the technical report, the information, method and procedure of collecting data related to the measured illuminance and luminance levels on site are presented. This second part of the technical report complements the first part by including an overview summary of the gathered data including SPD and CCT at the horizontal ground and vertical eye level measurements recorded by hand-held spectrometer devices and wearable LYS button sensors. The work was conducted as part of the interdisciplinary research project NorDark.