What Are Daylighting Strategies?
Daylighting strategies are architectural techniques that bring natural sunlight into a building's interior to reduce electric lighting use, improve occupant well-being, and cut energy costs. They combine building orientation, window and skylight design, and light-directing devices.
Daylighting strategies are design methods — orientation, glazing, light shelves, skylights, and shading — used to maximize useful daylight indoors while controlling glare, often measured with the daylight factor.
- 1↓Orient & analyze siteStudy sun path, climate and surrounding obstructions to plan window placement.
- 2↓Size aperturesProportion windows and skylights to room depth for even light penetration.
- 3↓Add light-directing devicesUse light shelves, light tubes or clerestories to push light deeper into the room.
- 4↓Control glare & heatAdd shading, diffusing glass or overhangs to cut direct glare and solar gain.
- 5Verify with daylight factorCheck daylight factor or simulation results meet the target (e.g., 2% average).
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Step-by-step worked examples
A classroom has an indoor illuminance of 250 lux at the back wall under an overcast sky where outdoor horizontal illuminance is 10,000 lux. Find the daylight factor.
DF = (Ei/Eo) × 100 DF = (250/10000) × 100 DF = 2.5%
An office point receives 150 lux indoors while the overcast outdoor illuminance is 12,000 lux.
DF = (150/12000) × 100 DF = 1.25% This is below the recommended 2% minimum for well-daylit spaces.
Design target: DF = 3% under an outdoor illuminance of 8,000 lux. What indoor illuminance is required?
DF = (Ei/Eo) × 100 3 = (Ei/8000) × 100 Ei = 0.03 × 8000 = 240 lux
Flashcards
Quick quiz
Q1.What does the daylight factor measure?
Q2.Which device redirects daylight deeper into a room while shading the area beneath it?
Q3.Indoor illuminance is 200 lux and outdoor overcast illuminance is 10,000 lux. What is the daylight factor?
Q4.Why is glare control included in daylighting strategy?
The full card deck, worked steps and AI-tutor support for “What Are Daylighting Strategies?” are in Notek — study by hand before your exam.
Common mistakes
More window area always means better daylighting. — Correct: Oversized, unshaded glazing causes glare and overheating — size and placement matter more than raw area.
Daylight factor is measured on a sunny day. — Correct: It's standardized under an overcast sky so results don't depend on sun position or time.
Skylights alone solve daylighting for any room shape. — Correct: Deep or narrow rooms often need light shelves, clerestories, or light tubes in addition to skylights.
Daylighting design ignores glare. — Correct: Effective daylighting always pairs light-admitting strategies with glare and solar-heat control (shading, diffusing glass).
FAQ
What is daylighting in architecture?
Daylighting is the practice of using natural light through windows, skylights, and light-directing devices to illuminate interior spaces, reducing electric lighting energy use.
What is the daylight factor formula?
DF = (Ei/Eo) × 100, where Ei is indoor illuminance and Eo is outdoor horizontal illuminance under an overcast sky.
What are examples of daylighting strategies?
Building orientation, properly sized windows, skylights, clerestories, light shelves, light tubes, and shading devices.
How do you calculate daylighting factor for a room?
Measure or simulate indoor illuminance at a point, divide by outdoor overcast illuminance, then multiply by 100 to get a percentage.