Daylighting Performance in Heritage Architecture: A Case Study of the Eduljee Dinshaw Building

Introduction: Shedding Light on Heritage Design

In the field of heritage conservation and sustainable architecture, daylighting analysis has become a vital tool. It examines how natural light interacts with interior spaces over time, measuring illuminance levels and uniformity to assess visual comfort, energy efficiency, and spatial usability. In historic buildings, daylighting must be handled delicately—it needs to respect architectural heritage while supporting modern standards of human comfort and sustainability. This study focuses on the Eduljee Dinshaw Building in Karachi, a landmark colonial structure, to explore how intelligent daylight design can illuminate the path forward for heritage conservation.

Why Daylighting Analysis Matters in Heritage Buildings

Daylighting analysis in heritage buildings serves multiple purposes:

1. Conservation-compatible sustainability: Natural lighting reduces energy consumption, a critical aspect of sustainable design, without resorting to intrusive mechanical systems.
2. Material and visual preservation: Proper daylighting prevents UV damage to sensitive materials while preserving the spatial and atmospheric qualities of historic interiors.
3. Enhanced user experience: Optimized daylight improves well-being, productivity, and occupant satisfaction—essential in heritage buildings now repurposed for public or commercial use.
4. Compliance and design integration: It supports informed decision-making within HBIM (Historic Building Information Modeling) environments, balancing performance and authenticity.

‍

Tools & Methodology: Autodesk Revit Simulation

To conduct this study, Autodesk Revit was used to simulate daylight performance within the Eduljee Dinshaw Building. The chosen simulation date, September 21, represents an average solar condition in Karachi, offering a balanced understanding of typical daylight exposure.

Two key times—9:00 AM and 3:00 PM—were selected for analysis, reflecting peak occupancy hours. The simulation calculated illuminance levels in lux, a unit that quantifies luminous flux per unit area and directly correlates with visual comfort and performance.

Key Findings: Quantifying Light and Shadow

The simulation revealed significant daylight inefficiencies across the building’s interior:

1. At 9:00 AM, 84% of the floor area received below-recommended daylight levels (<300 lux).
2. At 3:00 PM, daylight conditions remained suboptimal—again with 84% underlit, and 7–8% areas overlit, particularly in zones with direct solar exposure and no shading.
3. Overall, daylight sufficiency was below recommended thresholds 85% of the time.
4. Façade illuminance varied dramatically, from near-zero values in shadowed corners to over 5000 lux in sun-exposed regions, indicating extreme variability due to orientation and obstructions.

Implications for Comfort, Conservation, and Energy Use

These results raise several concerns, particularly in the context of heritage conservation:

1. Visual Discomfort: Both overlit and underlit areas can create discomfort, affecting building usability.
2. Increased Artificial Lighting Demand: Poor daylight distribution increases reliance on electrical lighting, contradicting sustainability goals.
3. Energy Inefficiency: Heritage buildings typically lack HVAC systems designed for modern energy performance. Inefficient lighting compounds energy usage, undermining conservation efforts.
4. Limitations on Retrofit Options: Given the historic significance of the Eduljee Dinshaw Building, conventional mechanical interventions must be minimized—making passive daylight strategies essential.

‍

Design Recommendations: Enhancing Light Without Compromising Heritage

To address the imbalance in daylight exposure and improve overall building performance while preserving architectural integrity, the following daylight enhancement strategies are proposed:

1. Reposition or resize window openings, especially in deep interior zones, to increase daylight penetration without altering the building’s historic character.
2. Incorporate reflective interior finishes (e.g., lighter wall and ceiling materials) to scatter natural light more evenly.
3. Add light shelves or clerestory windows where appropriate to redirect sunlight deeper into the interior.
4. Use selective shading devices—like interior blinds, exterior louvers, or heritage-compatible canopies—to reduce glare and mitigate overexposure in sun-intense areas.

These strategies, if sensitively applied, can significantly improve daylighting while upholding the cultural and visual identity of the building.

HBIM and the Future of Light-Sensitive Heritage Planning

The integration of daylighting simulations within Historic Building Information Modeling (HBIM) allows for early-stage assessments of lighting performance in digital heritage models. This approach supports data-driven conservation decisions, enabling multidisciplinary teams to assess comfort, energy use, and design alterations within a virtual environment.

The Eduljee Dinshaw Building’s case exemplifies how digital daylighting tools can guide subtle yet impactful interventions—bridging the gap between sustainable performance and architectural preservation.

Conclusion: Illuminating the Future of Heritage Buildings

Daylighting analysis goes beyond technical metrics—it offers a lens through which we can view historic buildings as living, adaptive spaces. By understanding how natural light interacts with heritage interiors, architects and conservators can make informed choices that enhance both energy performance and occupant well-being.

The Eduljee Dinshaw Building stands as a beacon of this integrated approach. With the help of tools like Autodesk Revit and the principles of HBIM, we can ensure that heritage structures are not only admired for their past but also equipped to thrive in a sustainable, light-filled future.

‍