Impact of facade colour on visual preference, visual perception, and outdoor thermal comfort in a Swedish urban environment

Abstract

With increasing population growth and urbanization, the demand for new construction continues to rise. This expansion places significant pressure on the environment. It contributes to reduced daylight and sunlight access, an increase in hard, heat absorbing surfaces, and the deterioration of outdoor thermal comfort. It also exposes urban residents to higher levels of air pollution and noise, while further intensifying global warming. Although numerous design strategies have been proposed to mitigate these challenges, the influence of facade colour remains comparatively underexplored. This study examines how facade colour affects visual preferences and perception, and outdoor thermal comfort for pedestrians in a Swedish urban context.

A curated palette of ten colours inspired by historical and contemporary Nordic architecture was developed from which six case study buildings were selected. Visual preference and perception were evaluated through participant surveys. Outdoor thermal comfort was assessed through microclimate simulations conducted in CitySim Pro for one of the case study locations.

The aim of this thesis is to advance understanding of the role of colour in urban environments. Specifically, the study addresses research questions concerning pedestrians’ preferences, dislikes, and visual perception in relation to facade colour in urban settings. In addition, the influence of colour reflectance was examined to determine how facade colour properties affect outdoor thermal comfort.

The results indicate that colour preferences vary across demographic groups. Within the curated palette, Swedish participants most frequently preferred green, whereas non Swedish participants preferred beige. When selecting from images of the case study buildings, Swedish participants showed a preference for yellow facades, while non Swedish participants preferred white. Brown was the most disliked colour among Swedish respondents, and black among non Swedish respondents. Across all six case study sites, black and blue emerged as the least preferred facade colours for both groups. Open ended responses further revealed that participants often distinguished between liking a colour in general and liking it on a building, highlighting the context-dependent nature of colour preference. Colours with high preferences were perceived as comfortable, pleasant, calming, and soft. Warm colours made participants feel warm, whereas cool colours made them feel cool.

Beyond perceptual effects, colour reflectance significantly influenced outdoor thermal comfort. Its impact depended on solar exposure, orientation, and local climate. Lower reflectance (higher absorptance) increases surface temperatures, thereby affecting mean radiant temperature (MRT) and physiological equivalent temperature (PET). South-facing facades received the highest solar radiation and consequently exhibited the highest surface temperatures, particularly for low reflectance colours. Orientation changes produced different temperature fluctuation patterns due to shifting sun altitude.

However, PET is shaped by multiple factors beyond colour reflectance, including wind, humidity, activity level, and clothing. In Sweden’s cold winters, low solar radiation limited the influence of colour reflectance on thermal comfort. In summer, wind speed and orientation occasionally made darker colours with higher surface temperatures feel more comfortable. Overall, the findings show that facade colour is not merely an aesthetic decision but a determinant of both visual experience and thermal conditions in urban spaces. Integrating user preferences with site specific climate, geometry, orientation, and seasonal variation is essential for informed design decisions that enhance visual and thermal comfort in Swedish urban environments.

Popular Abstract

With rising heat island effects due to climate change and reduced daylight in dense cities, the study wondered whether colour could be an aspect to consider in urban planning. It examined how colour reflectance shapes outdoor thermal comfort, which colours Swedish residents prefer or dislike, and how facade colour impacts visual perception in their everyday surroundings.

The method of the study was a combination of subjective assessment and simulation. The study first researched the historical use of colour in Swedish buildings to understand how facade colours have evolved. It also reviewed literature on preferred facade colours within the Swedish architectural context. Based on this, a colour palette was developed, and six case study sites were selected that represented colours from the palette. A digital survey was then conducted to investigate people’s visual preferences, perceptions, and perceived thermal comfort. After collecting the survey responses, data analysis was carried out to interpret the results. For the outdoor thermal comfort assessment, colour reflectance was measured directly on site and these values were used for simulations in CitySim Pro. The surface temperature and view factors were obtained from the results of the simulation. The MRT and PET were then calculated to evaluate outdoor thermal comfort.

Several findings were identified in the study. Firstly, the visual preferences and perceptions differed across age, gender, ethnicity, and cultural background. Swedish participants preferred yellow facades, while non Swedish residents preferred white; blue and black facades were consistently disliked across all demographics. Mixed colour facades were also rated more positively than single dominant colours. Warm colours made people feel warmer, while cool colours created a cooler impression in urban spaces. The study also found that colour reflectance is a key attribute: low reflectance, high absorptance colours can raise surface and mean radiant temperatures (MRT) by up to 40% compared to high reflectance colours, significantly influencing physiological equivalent temperature (PET) and overall outdoor thermal comfort.

Moreover, the study addressed the need to understand how colour reflectance with solar exposure influences outdoor thermal comfort, and how people’s responses to colour can enhance urban experience. Although people spend most of their time indoors, being outdoors in good daylight and a comfortable thermal environment is essential for health. Another need identified was the gap in architectural practice: architects often choose facade colours based on their own preferences instead of people’s preferences.

Since colour influences mood and user experience more deeply than commonly assumed, it is important to understand what people prefer and what they dislike, and how different colours are perceived in urban spaces. Addressing these needs can help create outdoor environments that support visual perception, improve thermal comfort, and enhance the overall quality of urban life.

Hence, the study can be used by urban planners and architects to better understand people’s colour preferences and how these preferences shape outdoor thermal comfort. It also highlights the broader value of colour, showing why colour considerations should be integrated early in the design process as a design tool impact microclimate rather than treated as an afterthought for aesthetic purposes. In addition, the findings point to opportunities for future research on how the properties of colour can be further utilised in urban environments.

Even though the study initially expected lighter, high reflectance colours to reduce surface temperatures and improve outdoor thermal comfort, it found the opposite in the Swedish climate. Darker, low reflectance, high absorptance facades provided more comfortable summer hours at the Swedish site, driven by the combination of high wind speed, humidity, and outdoor air temperature. This shows that colour reflectance depends strongly on geographical location and solar exposure, and that darker colours do not always cause outdoor overheating. Sometimes darker colours are what is needed to raise the outdoor temperature to an acceptable level, even in the summer! The study also found that outdoor thermal comfort is influenced not only by colour reflectance, but by orientation, aspect ratio, wind speed, humidity, people’s activity, and clothing. Moreover, although colour is rarely considered as a strategy for reducing heating load, the study found that low reflectance, high absorptance colours can help lower heating demand by up to 10%.

• author: Issana, Tasnim and Tahseen, Farhana
• supervisor: Marie-Claude Dubois
• organization: Division of Energy and Building Design
• course: AEBM01 20261
• year: 2026
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• keywords: Facade colour, visual preference, visual perception, outdoor thermal comfort, facade colour reflectance, Swedish urban context.
• language: English
• id: 9251963
• date added to LUP: 2026-09-29 09:34:05
• date last changed: 2026-09-29 09:34:05