Passive Lighting Strategies for Resilient Buildings


Designing a building assimilating the use of the unlimited green resource of light from the sun for meeting the lighting requirements during the day should be a primary concern of every practitioner. Diligent use and good design can reduce up to 70% lighting expenditures of buildings, being free and inexhaustible. If done incorrectly, it could degrade occupant comfort and in turn, increase the heat load/cooling load on the building and its cooling/heating energy consumption. 

Planning spaces according to lighting requirement

Space planning in buildings is often done giving ample regard to the sunlight for centuries. Living areas, kitchen, laundry, etc which are utilized during the day should be preferably placed in the north, east, or sometimes west side of the house, however, bedrooms can be located in the south side as the major use is during the night and it has a chance to cool down by then. Usually, the North façade can pertain to the maximum glazing as the north light is free from glare. And east side has relatively low radiation and early morning glare which is quite bearable and auspicious. South and west have the maximum glare.

Image credits @ Halkidiki Properties

Appropriate Fenestrations

Fenestration pattern and configuration play a crucial role in building design as it involves area, shape, location & orientation of the windows and affects the air movement, daylight & glare indoors. Design of fenestrations is done giving high regards to the climate and orientation of the structure. For HOT climates, windows must be appropriately shaded and cover a relatively smaller area of the walls to minimize radiation. High openings or ventilators as desired in such climate as hot air rises and they act as effective heat vents. Whereas windows for COLD climates can be large and unshaded but airtightness is crucial to avoid airflow. COMPOSITE climates are a little challenging as suitable shading device design for balancing between cutting off summer sun, allowing winter sun & facilitating ventilation is needed.

Clerestory windows

Clerestory windows are age-old, but their potential hasn't been utilized to the fullest because of the lack of awareness. They are usually installed at the upper parts of tall walls, bringing in glare-free light having its location to its advantage. These windows will not only help admit additional light to your interiors but also improve the airflow inside the structure. Another major advantage is that they can facilitate in giving the habitant the much-needed sense of privacy which can be vital for some locations.

Although the light entering from these windows is usually pleasant, it could invite a little glare at some parts of the day, if placed in the South or West when the sun is harsh. This phenomenon can be controlled by using additional devices like light shelves, the incident light from the sun falls on the horizontal surface of the shelf and is reflected inside the building a diffused and uniform effect.

Image credits @ Michael Moran

Maximizing reflection

For the optimal use of daylight, it needs to reach every part of the building. The light that incidents on the walls and ceiling needs to be further reflected internally. Designers can tactically use materials, colours, and textures such that the illumination is amplified easily. Light colours, smooth surfaces, use of mirrors, translucent materials, etc. can be some of the approaches for improving reflectivity.

Skylights

A smart way to incorporate natural light deep inside massive buildings can be through skylights. They have to be properly treated to resist rain, harsh radiation and have a sturdy built. Materials like double glass, UV stabilized plastic, or sealed insulating glass units are used, which are treated to different degrees for enhancing user comfort. According to the specific aesthetic and thermal requirements, tubular, domical, pyramidal, or vaulted skylights can be customized to be ventilated or otherwise. Experimenting with skylights can be a way to add more fun to interior spaces, with the interesting skiagraphies curated throughout the day.

You may also like