Impact of Urban Block Geometry on Daylight Performance Across Swedish Latitudes

Abstract

Urban densification is increasingly promoted as a strategy for sustainable urban development, yet it poses significant challenges for access to daylight and sunlight, particularly in Nordic climates where natural light is limited for large parts of the year. In Sweden, ensuring adequate daylight in residential environments is both a regulatory requirement and a critical factor for occupant well-being. This thesis investigates how urban residential block typology, with a focus on built courtyard blocks, influences daylight and solar access under conditions of increased density.
The study employs a simulation-based approach to analyse the effects of key geometric variables, including building width, depth, height, and setbacks, on daylight and solar performance. Daylight and sunlight conditions are evaluated using a range of quantitative metrics, including daylight factors, spatial daylight autonomy, useful daylight illuminance, direct annual sun hours, solar radiation, and sunlight exposure, assessed in relation to relevant standards. The analysis examines both indoor and outdoor performance at dwelling and facade levels.
The results show that building height and the height-to-width ratio are the most important geometric variables affecting daylight and solar performance. Keeping building height low and the H/W ratio below a critical threshold are the most effective measures for maintaining adequate daylight in courtyard blocks. Setback configurations perform best among tall building strategies for interior daylighting. The findings also show that geometric optimisation has clear limits set by latitude, and that no realistic courtyard configuration meets current EN 17037 requirements in the northern Swedish context. This suggests that existing standards may need to be reconsidered to better account for the conditions found in Nordic climates.

Popular Abstract

How much does building shape actually matter for daylight in Nordic cities?
Most people want a home with good natural light. In Sweden, where winter days can be very
short and grey, access to daylight is not just a matter of comfort but of health and wellbeing. Yet
Swedish cities are under growing pressure to build more housing in already built-up areas. More
floors, more units, more density. Squeezing more buildings into the same space inevitably means
less sky visible from each window and less sunlight reaching the homes and courtyards below. In
a country where winter darkness is already a fact of life, this trade-off deserves more attention
than it typically gets.
One common way of building densely in Swedish cities is the courtyard block, a cluster of
buildings arranged around a shared outdoor space. It is a form most Swedes would recognise
from older neighbourhoods in Malmö, Gothenburg and Stockholm. It has long been considered a
sensible balance between density and liveability. But as cities push to build higher and tighter,
that balance is increasingly at risk.
This thesis started from a simple question: when you change the shape of a courtyard block, how
much does it actually change the daylight inside the homes? To find out, hundreds of different
configurations were simulated and tested across three Swedish cities, from Malmö in the south to
Kiruna in the far north.
Some findings confirmed what architects and planners might already suspect. Others were more
surprising. One of the more unexpected results was how well setback buildings performed. These
are buildings where the upper floors step back from the street rather than rising as a straight
vertical wall, a form perhaps most associated with the iconic skyline of early twentieth century
New York, where it was actually introduced by law to stop streets from being plunged into
permanent shadow. In Sweden this form is almost never used. The simulations suggest it might
be worth reconsidering.
The most striking finding, however, had little to do with design at all. In Kiruna, no matter how
the block was shaped, daylight levels fell short of current European standards. The problem was
not the architecture. It was the latitude. The standards themselves appear to have been written
with sunnier places in mind, and no realistic design choice can compensate for the darkness of a
northern Swedish winter. If the goal is genuinely adequate daylight for everyone in the country,
the rules may need to change alongside the buildings.

• author: Natsi, Anna Maria and Gulalia, Himadri
• 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: Daylighting design, Median daylight factor, Average daylight factor, Average daylight autonomy, LD - Lighting dependency, sDA - Spatial daylight autonomy, DGP - Daylight glare probability, UDI - Useful Daylight Illuminance
• language: English
• id: 9228805
• date added to LUP: 2026-06-02 13:14:58
• date last changed: 2026-06-02 13:14:58