In modern architecture, daylighting transcends basic illumination – it enhances energy efficiency, occupant well-being, and the creation of high-performance buildings. Certification systems such as LEED and BREEAM recognize the key role daylighting plays in allowing projects to reach their sustainability goals, although they approach it differently. In this article we’ll explore how LEED addresses daylighting, compare it to BREEAM, and look at real-world case studies where daylighting systems have helped projects meet ambitious sustainability goals.
Introduced by the US Green Building Council (USGBC) in 1998, LEED (Leadership in Energy and Environmental Design) is the most widely used sustainability building rating system in the world, providing a framework for creating healthy, highly efficient, cost-saving buildings.
Purpose of the Daylight Credit
LEED's daylight credit is designed to reduce dependence on artificial lighting, enhance occupant comfort and well-being, and support productivity and mood through natural lighting conditions. These three objectives align with LEED’s mission to promote healthy, high-performance buildings.
Credit Requirements
Projects must demonstrate adequate daylight illuminance levels in regularly occupied spaces to earn the LEED daylight credit. There are three possible routes to compliance:
1. Dynamic Simulation – Spatial Daylight Autonomy (sDA 300/50):
Recently updated in V4.1 Beta, projects must now achieve:
At least 40% sDA (300 lux for 50% of the building’s occupied hours) across 55% or more of the regularly occupied floor area to earn 1 point
Higher thresholds than the previous 55% target, which now earns 2 points, with 3 points being awarded for 75% sDA.
This provides a dynamic, year-round simulation of daylight availability and is considered the most rigorous and comprehensive method of measurement.
2. Simulation – Illuminance Modeling:
This is a more straightforward modeling approach using specific time and sky conditions (typically 9am and 3pm on the equinox). According to v4.1, illuminance levels must be:
Between 300 and 3,000 lux for a minimum of 55% of regularly occupied space, lowered from the previous minimum of 75%, which now earns 2 points.
The latest update also means that areas with view-preserving automatic glare control devices need only comply with the minimum 300 lux level.
3. On-site Measurement:
For actual on-site measurements of daylight levels under clear sky conditions, readings for each regularly occupied space must fall within:
The 300-3,000 lux range on a clear-sky day between 9am and 3pm.
Glare-controlled spaces require onlywith view-preserving automatic glare control devices need only comply with the minimum 300 lux level.
Precision in Daylight Performance
LEED v4.1 rating system for Building Design and Construction (BD+C) places a strong emphasis on daylighting in its Indoor Environmental Quality (IEQ) category under the ‘EQ Credit: Daylight.’
Purpose of the Daylight Credit
LEED's daylight credit is designed to reduce dependence on artificial lighting, enhance occupant comfort and well-being, and support productivity and mood through natural lighting conditions. These three objectives align with LEED’s mission to promote healthy, high-performance buildings.
Credit Requirements
Projects must demonstrate adequate daylight illuminance levels in regularly occupied spaces to earn the LEED daylight credit. There are three possible routes to compliance:
Recently updated in V4.1 Beta, projects must now achieve:
At least 40% sDA (300 lux for 50% of the building’s occupied hours) across 55% or more of the regularly occupied floor area to earn 1 point
Higher thresholds than the previous 55% target, which now earns 2 points, with 3 points being awarded for 75% sDA.
This provides a dynamic, year-round simulation of daylight availability and is considered the most rigorous and comprehensive method of measurement.
This is a more straightforward modeling approach using specific time and sky conditions (typically 9am and 3pm on the equinox). According to v4.1, illuminance levels must be:
Between 300 and 3,000 lux for a minimum of 55% of regularly occupied space, lowered from the previous minimum of 75%, which now earns 2 points.
The latest update also means that areas with view-preserving automatic glare control devices need only comply with the minimum 300 lux level.
For actual on-site measurements of daylight levels under clear sky conditions, readings for each regularly occupied space must fall within:
The 300-3,000 lux range on a clear-sky day between 9am and 3pm.
Glare-controlled spaces require onlywith view-preserving automatic glare control devices need only comply with the minimum 300 lux level.
Toward Near-Zero Carbon & Enhanced Well-Being
LEED v5 provides a framework for the creation of near-zero carbon buildings, with a revamped scoring system. Half of the available points relate to climate action, while the other half are split between quality of life and ecological initiatives.
Lighting Environment (Occupant Experience Credit): Improving occupant health, wellness, and overall quality of life is addressed through the Occupant Experience credit. As part of this, designers can achieve points by ensuring a healthy and productive Lighting Environment. This includes ensuring effective daylighting access by using daylight simulation analysis to optimize visual comfort and reduce glare.
Embodied Carbon Reduction: The focus on embodied carbon has increased significantly in LEED v5. It introduces a new credit concept focused explicitly on procuring low-carbon construction materials as part of the broader effort to reduce the embodied carbon footprint associated with building materials.
Option 1: Whole-building lifecycle assessment (LCA): This option requires a comprehensive assessment of the building’s lifecycle to identify and reduce embodied carbon.
Option 2: Low-carbon procurement: This simplified option focuses on procuring specific low-carbon materials. By reducing complexity and focusing on high-impact materials, it aims to be more accessible and straightforward than previous versions.
Option 3: Environmental Product Declarations (EPDs): This option involves using materials with verified EPDs, emphasizing transparency and environmental performance.
This shift highlights the importance of considering the entire lifecycle of building materials—including those used for daylighting— through Whole-Building Life Cycle Assessment (LCA). LEED v5’s incorporation of Whole-Building Life Cycle Assessment (LCA) and Life Cycle Thinking, as part of its comprehensive approach to sustainable building practices, involves evaluating a building’s environmental impact from construction and operation to final demolition or reuse, so that projects not only meet immediate environmental goals but also consider long-term ecological effects.
(Building Research Establishment Environmental Assessment Method)
BREEAM provides a framework to encourage clients and designers to strive for the most sustainable building within the constraints of the project.
BREEAM (Building Research Establishment Environmental Assessment Method) International New construction is the standard used for new developments in the USA. While the issues addressed are the same as the usual BREEAM standard, this international version provides ways to adapt section weightings to reflect the environmental conditions specific to the country of assessment. This regional approach is to make sure that any BREEAM certified project exceeds local regulations. The USA has been divided into 10 regions, based on climate, energy use, transport availability, population density, ecology and other factors. You can learn more about the weightings here.
BREEAM International New construction approaches daylighting through its Hea 01 Visual Comfort credit. This system generally uses daylight factor calculations, focusing on:
While BREEAM's method can be considered more prescriptive than LEED’s dynamic and performance-based approach, both standards aim to ensure high-quality lighting environments. To illustrate this, we have created a table that sets the BREEAM requirements against that of LEED v4.1.
| Category | LEED v4/v4.1 (EQ Credit: Daylight) | BREEAM (Hea 01 Visual Comfort) |
| Primary Objective | Ensure adequate natural lighting while supporting occupant comfort and reducing energy use | Ensure sufficient daylight provision to improve occupant wellbeing and reduce artificial lighting demand |
| Assessment Method | Dynamic simulation (sDA and ASE), illuminance simulations, or physical measurement | Static daylight factor calculations under overcast sky conditions |
| Key Metrics |
|
|
| Glare Control Requirement | Required for all compliance paths (eg. blinds, dynamic glazing) | Must demonstrate glare is controlled (eg. shading, design strategies) |
| Occupant-Centric Approach | Yes – considers time of use, area, and daylight availability throughout the year | No – evaluates a single point in time under overcast sky conditions |
| Climate Consideration | High – includes real-world annual weather data in simulations | Low – uses standard CIE overcast sky model only |
| Compliance Tools | Radiance, ClimateStudio, Solatube Design Calculator, etc. | BRE Daylight and Sunlight guidance, simple simulation tools, BRE-recommended spreadsheets |
| Certification Influence | 1-3 points depending on the level of daylight achieved | 1-2 credits depending on building type and performance |
| Innovation Credit Eligibility | Yes, for exemplary performance or integration with other wellness strategies | Possible if integrated into broader visual comfort or occupant health strategies |
Below are six standout examples where daylighting played a central role in achieving LEED certification and elevating building performance.
LEED Certification: Platinum / Daylighting Solution: 66 Solatube Daylighting Systems, including SolaMaster 750 DS-O, 330 DS-C, and SkyVault M74 DS units
Ecofibre integrated high-performance tubular daylighting across its office, warehouse, and cleanroom spaces to support its sustainability and wellness mission, providing a 58% reduction in total energy consumption.
LEED Certification: Platinum / Daylighting Solution: 2,630 sq ft of UniQuad® translucent wall panels
To daylight the fire station’s interiors, UniQuad® panels were used to manage west-facing glare while maintaining energy efficiency. The system helped reduce energy use by 70% and supported a healthy, glare-free environment.
LEED Certification: Platinum (Net Zero Energy design) / Daylighting Solution: Solatube SolaMaster Series 330 and 750 DS-C with long tubing and 90° bends
Solatube daylighting systems channeled natural light deep into the second and third-floor corridors of ASU’s Student Pavilion, improving comfort and reducing energy demand to support the building’s Net Zero goals.
LEED Certification: Certified / Daylighting Solution: UniQuad® translucent wall system, PentaClad® cladding system
This project integrated UniQuad® translucent wall panels and PentaClad® cladding to create a versatile manufacturing, office, and lab space, enhancing aesthetic appeal and optimizing natural light.