In recent years, I have been exploring daylight analysis and energy modelling during the concept design phase of architectural projects. The process begins with a general daylight analysis, measured in Lux, to assess the performance of spaces throughout the year based on design, location, and weather. A desirable target is 300 Lux or above for residential spaces, but I aim for a balanced composition of light and shadow rather than maximizing daylight in every corner. This analysis is visualised in diagrams showing over and underlit spaces, which guide design adjustments, such as adding rooflights to improve lighting in specific areas.

The Spatial Daylight Autonomy (sDA) analysis measures how much of a space receives adequate daylight, focusing on the percentage of floor area that meets minimum illumination levels for a significant portion of occupied hours. A score of 55% is considered adequate, with 75% being excellent. I use sDA to refine designs, adjusting elements like glazing and ceiling heights. Another metric, Annual Sun Exposure (ASE), highlights areas receiving excessive sunlight, which can lead to thermal discomfort. While keeping ASE under 50% is ideal, this can be challenging and not always desirable, especially in passive solar designs.

Beyond quantitative measures, I also assess the poetic quality of light using the Daylight Factor, which simulates daylight under overcast conditions. This analysis reveals spaces with fluctuating light qualities, akin to those in galleries or museums, offering a deeper understanding of a design’s atmospheric potential. Additionally, I evaluate direct sunlight hours during winter to inform a passive thermal strategy, integrating thermal mass and controlled roof openings.

Finally, I create a simple energy model to estimate energy use. In one project, a draft analysis predicted a 48% reduction in energy use compared to a traditional structure, suggesting further refinements during technical design. Overall, this approach underscores the importance of integrating energy reduction strategies from the outset, moving beyond regulatory requirements toward a more context-sensitive, sustainable design.

Image: Daylight Factor Analysis.