The Challenges in Aligning Environmental and Daylight Performance when Transforming Industrial Buildings into Perimeter Offices

Abstract

Increased emphasis on sustainable practices and reducing the global warming potential (GWP) kg CO2 equivalent emissions of buildings and construction processes to mitigate climate change has led to a growing interest in refurbishment and transformation of existing buildings. However, balancing daylight provision with environmental impact targets can be challenging, especially in high-latitude Nordic countries and when industrial buildings are transformed into regularly occupied office spaces. One reason is the potential misalignment between thresholds in the European daylight standard (EN 17037) and national CO2 limit values. Another reason is the limited availability of daylight hours, which means that large windows are often required to ensure adequate daylighting; however, they can also come at an environmental cost, as they can lead to higher heat loss and increased embodied carbon. Therefore, this study investigated the challenges in managing the alignment of both.
To undertake the investigation, the European daylight standard criteria and national environmental requirements in Nordic countries were reviewed and compared. Denmark was found to have the strictest regulations for both daylight and environmental building performance and was thus chosen as the study’s context. Several case studies were assessed for energy and daylight performance by simulating them. The case studies consisted of transforming three industrial formal typologies into office buildings, combined with life cycle assessment (LCA) via multi-objective optimization for varying daylight provision thresholds (minimum, medium, and high), as defined in EN 17037. The three selected formal typologies were a single-story bi-axial building with a sawtooth roof, a multi-story mono-axial building with a barrel roof and ridge skylight, and a multi-story bi-axial building with a flat roof and scattered skylights.
Results seemed to indicate a slight positive trend between GWP emissions and sDA results for low-carbon facade materials and a slight negative trend with carbon-intensive insulation and façade materials due to the difference in whole life carbon between windows and opaque façade walls. However, no issues in aligning daylight provisions with current Danish LCA limits of 12 kgCO2eq/m²/y were found for both. For upcoming limits (7.5 kgCO2eq/m²/y), only low-carbon insulation materials complied, and even lower future targets will pose a challenge, especially once the construction process life cycle stages are added.

Popular Abstract

Facing the Future: The Carbon Cost of Daylight

Daylight flooding a room is often what makes spaces pleasant and comfortable, but designing these at a time when carbon emissions must be drastically reduced to ensure a livable future could become a significant architectural challenge.
To reduce the environmental impact of the building industry, which currently accounts for around 30 % of global CO2 emissions, existing industrial buildings need to be repurposed and transformed into residential or workspaces. Yet, ensuring sufficient daylight in spaces not originally designed for human occupancy can be challenging. Daylight, essential for health, productivity, and well-being, can increase carbon emissions due to higher heat losses through windows and carbon-intensive materials like glazing. This is a challenge in Nordic countries, like Denmark, where daylight hours are limited, and in offices, where people spend most daylight hours indoors. So, how do we balance the need for light with cutting carbon emissions?
That’s what we explored in this degree project: The challenges in aligning daylight and carbon goals when transforming three industrial building forms in Denmark into offices. We explored how daylight is being assessed, how European standards align (or don’t), and what future environmental regulations might require. To uncover the trade-offs, we ran more than 1 800 simulations, assessing energy use, daylight provision, and environmental impact.
The findings revealed that higher daylight levels seemed to come at the cost of increased carbon emissions, especially when combined with low-carbon opaque facades, like biogenic insulation made of wood fiber and wooden cladding. Additionally, although all building types complied with current Danish carbon limits, many designs exceeded future limit values, especially when aiming for more than the minimum required light.
Beyond these simulation-based insights, we found several systematic issues: Misalignment between European standards, a discrepancy between declared and actual product performance, and inconsistent definitions and guidelines.
Perhaps the most critical insight was that current daylight targets may be too ambitious for future carbon budgets. If we want to stay within a 1.5 °C global warming threshold, compromises may be unavoidable, either for how much light enters a room or what materials we use, because current standard low-carbon materials may still have a high environmental impact.
Our work highlights the importance of early-stage integration, linking daylight simulations, environmental analyses, and material choices. Furthermore, parametric HVAC systems, reusing existing top lighting, and assessing sizes of atria in combination with all previously mentioned aspects should be investigated more. Because, in the years ahead, we may need to rethink how we design for daylight so that buildings continue to support human and planetary health simultaneously.

• author: Carstens, Pauline and Fokas, Luca
• supervisor: Niko Gentile; Shivani Mutatkar; Victoria Alpenhorn
• organization: Division of Energy and Building Design
• course: AEBM01 20251
• year: 2025
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering; Arts and Architecture
• keywords: Daylight Provision, Life Cycle Assessment (LCA), Transformation, Whole Life Carbon (WLC), Embodied Carbon, Operational Carbon, Spatial Daylight Autonomy (sDA), Global Warming Potential (GWP), European Standard
• language: English
• id: 9200026
• date added to LUP: 2025-06-16 11:46:25
• date last changed: 2025-06-16 11:46:25