- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 20 Feb 2020
A light shelf is a passive architectural device used to reflect natural daylight into a building. 'Bouncing' sunlight off a horizontal surface distributes it more evenly and deeply within a space, whereas direct sunlight can cause glare near an opening, whilst leaving dark areas further in.
Light shelves can be fixed either externally, internally or both (which often works best in providing an even illumination gradient). They are often designed as part of a broader daylight and shading strategy.
They are generally found on walls facing the sun, as on 'pole-facing walls' would tend to act only as sunshades. On east and west orientations, they may act as an effective means of reducing direct heat gain and glare but will not bounce light as deeply into the space.
Internal light shelves however may be easier to maintain as they can be more accessible and less exposed. In very broad terms, internal light shelves tend to have a depth similar to the height of the opening that they sit below.
Light shelves are commonly made from; timber, glass, plastics, metal panels, plaster, acoustic panels and so on. The choice of material may be determined by considerations regarding the design of the rest of the building, structural strength, ease of maintenance, cost, durability and so on. Opacity is not essential, as some transparency can help more-evenly distribute light.
To be able to reflect light up to the ceiling, the upper surface of light shelves should be matte white or diffusely specular, it does not need to be shiny or reflective. Ideally, the ceiling should also be a light colour.
Light shelves can:
- Enhance daylight quality.
- Reduce the need for artificial lighting and so reduce energy consumption.
- Reduce cooling loads.
- Increase occupant comfort and productivity.
- Enhance design aesthetics.
Some of the limitations or drawbacks of light shelves are as follows:
- They tend to be best-suited to mild rather than tropical or desert climates.
- They can interfere with the installation of sprinkler systems.
- They may require a higher floor-to-ceiling height.
- Their design must be coordinated with windows.
- They Increase maintenance requirements.
 Related articles on Designing Buildings Wiki
Featured articles and news
Highlighting the health benefits of home improvement.
Pavilions for music, entertainment, and leisure. Book review.
Broadening our understanding of Dublin’s chequered social history.
The charm of London's Cabmen's shelters.
Future Weather Files research tool looking for feedback.
Exploring the Colour Rendering Index.
Why it's important to find out what went wrong.
ECA reviews the shape of the construction job market.
Why proper room acoustics make a difference.
Initiative puts gas networks on the path to net zero.
WICE Woman Architectural Technologist of the Year 2019.
Traditional low-energy approaches to comfort.
Revisiting the McArthurGlen Designer Outlet in Ashford.
USA In-Use Version 6 is now available.
The rise of architectural barbarism.
In contentious political contexts heritage can be more fractious.
Civil engineering and the digital transformation.