Benefit From Natural Light

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BENEFIT FROM NATURAL LIGHT

Natural light improves the quality and comfort of homes by efficiently illuminating interior spaces while lowering the overall energy consumption. Increasing natural light or ‘daylighting’ a room can provide light to occupants when electricity is not available. Windows and doors bring in light, but they can also make a space too bright or too hot. While placement and size of windows and doors is an important aspect of new construction, modifying shading on existing buildings can make the most of daylight while reducing temperature rise indoors. See Strategy 10 Reduce Thermal Heat Transfer.

Strategy in Action

1. Orient Your Home to Maximize Natural Light

2. Control Natural Light

A. Vegetation

B. Window Size

3. Choose Your Shutters

4. Create Light Shelves

5. Create Skylights

WHAT YOU NEED TO KNOW

Daylighting is the utilization of sunlight to illuminate interior spaces.
The lighting quality in your home is determined by:
- Adjacencies: nearby structures, such as terraces or your neighbor’s home, as well as vegetation, impact how much natural light goes into your house.
- Building Openings: mechanisms, such as windows, doors, or skylights, that allow natural light in.

OPERATIONS AND MAINTENANCE TIPS

Trim plants on ongoing basis.
Check anchorage at shutter systems. Check for rust in metal elements and joints.
Wipe windows and glass to reduce glare from grease and exposure to dirt and dust which can impede visibility.
Ensure windows and penetrations into building appropriately water sealed to prevent water intrusion and pests.
Orient new Units of Housing to take advantage of Light.
Locate Vegetation Location to manage light exposure
Size Windows to take advantage of light.
Create Light Shelves and use Skylights to Open up Spaces to Light.

STEP 1 - CHOOSE THERMALLY EFFICIENT MATERIALS

The critical facades for sunlight are the ones located to the east, west and south. Orient a building in a way that the longer side faces north/ south, and the narrower side faces east/west.
Remember that the ideal proportion for maximizing passive systems is 1:3.
Ensure that building facades are protected against direct sunlight.
Remember that the ideal proportion for maximizing passive systems is 1:3.
Ensure that building façades are protected against direct sunlight.

WEST

In the afternoon, the West façade receives direct sunlight.
Place your porch on the West side if you intend on using it in the afternoon.

NORTH

Throughout the day, the North façade receives indirect sunlight.

SOUTH

Throughout the day, the South façade receives direct sunlight.

EAST

In the morning, the East façade receives direct sunlight.
Place your porch on the East side if you intend to use it in the morning.

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STEP 2 - CONTROL NATURAL LIGHT

A. VEGETATION

Trees reduce direct sunlight.
The foliage of the tree will provide the most shade. Ensure that the tree’s height relates to the opening you wish to protect.
Keep a distance between the greenery and the building to avoid damage during strong winds. The distance from the tree to the house should exceed the tree’s height.

WEST

Plant tall trees on the West side to reduce afternoon direct sunlight.

NORTH

Plant light greenery on the North side for glare control, if necessary.

SOUTH

Plant tall bushes on the South side to reduce day-long direct sunlight.

EAST

Plant tall trees on the East side to reduce morning direct sunlight.

B. WINDOW SIZE

Size your windows according to sun exposure in the home.

WEST

Minimize the quantity and size of openings in this façade. Since it is exposed to direct sunlight in the afternoon, it will increase heat gain.

NORTH

Maximize the quantity and size of openings in this façade. Near sunrise and sunset in the summer, the North facade can briefly receive direct sun, but the energy impact is low. In May, June and July, the sun can be slightly north of directly overhead but with the slightest overhang it will miss the north facade.

SOUTH

Shade openings, since they are constantly exposed to sunlight.

EAST

Minimize the quantity and size of openings in this façade. Since it is exposed to direct sunlight in the morning, it will increase heat gain.

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STEP 3 - CHOOSE YOUR SHUTTERS

Choose a product that is rated to be hurricane proofed.
Choose a product with following attributes for shades and curtains:
- Higher RS (Solar Reflectance) values mean lighter colors reflect more heat away
- Higher VLT (Visible Light Transmission) values mean more daylight is allowed to pass through
The most common types of shutters are jalousie windows.
If suitable for your building, lockable, exterior shutters anchored into a concrete frame will withstand an extreme weather event better than shutters anchored to a wood frame.
Choose your shutter materials based on your available budget, durability and availability.

SHUTTER STYLES

VERTICAL

Vertical oblique: Protects against sunlight entering from a horizontal direction, but not from above.

HORIZONTAL

Solid horizontal: It’s minimal geometry makes it structurally sound, but it only offers 50% of sun protection.
Movable horizontal devices: Provides full protection from the sun when completely open, and offers space to isolate heat between the shutter and the outside surface. Operable systems are recommended.

MIXED

Movable horizontal louvers: Protects opening from direct sunlight coming in from all directions.
Movable louvers: Allows the user to open during the part of day where the sun is not directly hitting each façade. Operable systems are recommended.

STEP 4 - CREATE LIGHT SHELVES

A horizontal unit installed in the interior of a space that:
- Blocks direct light from entering the home
- Redirects light to the ceiling to illuminate interiors indirectly.
Some systems in the market are operable and protect from high winds when shut.