Daylighting 101: Orientation

We've established that daylight improves our health, physiology and general wellbeing, so how do we maximize the benefits? If you're building from the ground up, it's easy to implement daylighting strategies in the overall design. Most of us don't have the luxury of building a new house simply to get better light, but the finishes and colors you use as well as where you place furniture and do certain activities can improve or diminish the daylight quality, so it's important to understand the basics.

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Orientation

When we talk about the orientation of a building, we mean how the building sits on the site relative to its context, to which the sun is always relevant (other factors being wind, views, topography and surrounding  landscapes, buildings and streets). It is easier to optimize the orientation of a building for solar exposure in new construction, but there are takeaways that can be applied to existing homes as well. 

If you live in the Northern Hemisphere, the sun is always to the south throughout the day, and the difference between north and south exposures are more dramatic the farther you are from the equator (sun angles are discussed below). Typically, buildings are oriented along an east-west axis to maximize southern exposure for this reason. A notable exception is Le Corbusier’s Unité d'Habitation, a famous apartment building with a central corridor oriented along the north-south axis so that all units have equal access to direct sunlight at some point during the day (as opposed to half of the building having access to direct southern sunlight throughout the day, while the other half to the north receives none).

Southern exposures: Southern light provides warm, ambient light throughout the day and generally feels sunny and comfortable. Most living spaces are ideal for southern exposure, as it brings in the most light and does not vary much over the course of the day. Southern light is warm, and cool colors like blues and greens tend to feel warmer. It is usually practical to maximize daylighting by orienting buildings so that spaces that require ample light for activities and comfort, and where occupants spend a majority of time, get the most southern exposure. Southern exposures must deal with heat gain, which can be beneficial if integrated with passive heating strategies, but detrimental where overheating and glare may be an issue. On buildings, you will typically see sun shades on the south facades to keep sun out during the summer while allowing it in during the winter when sun angles are lower. Passive heating and cooling will be covered in another blog post.

  • Best spaces/activities for south-facing windows: All living spaces, especially those used frequently.

  • Worst spaces/activities for south-facing windows: Spaces used infrequently or requiring darkness, such as bedrooms used only for sleeping, bathrooms, storage and TV rooms.

  • Best paint colors: Cool colors, neutrals with blue, green or purple undertones.

  • Decorating tip: Prioritize spaces near south-facing windows when considering your furniture layout and where you will spend the most time. 

  • Remodeling tip: If you're adding on or reconfiguring your interior layout, try to maximize the amount of living space that faces south and avoid blocking southern exposures with other architectural features. 

Northern exposures: Northern light is indirect, meaning that it is always in shadow and can cause spaces to feel dark and cold. North-facing windows receive the least amount of light of any orientation, but the benefit is that northern light it is diffuse and does not typically need to be controlled for glare. It is cooler in color than light from any other orientation, so warm colors (yellows, oranges and reds) as well as warm finishes like wood can help spaces with northern light feel more sunny. A major benefit of northern exposure is that the diffuse quality means that exterior shading is not required and glare is not a concern. However, larger openings must be used to bring in a comparable amount of light compared to other exposures.

  • Best spaces/activities for north-facing windows: Infrequently used rooms like storage, bathrooms, laundry rooms. Activities that require ambient light but cannot handle glare, such as office spaces and rooms with computer or TV screens, may benefit from northern exposure. 

  • Worst spaces/activities for north-facing windows: Frequently used rooms and sunrooms.

  • Best paint colors: Warm colors, neutrals with pink or gold undertones.

  • Decorating tip: Keep furniture used for seating and areas that people gather away from chilly north-facing windows to increase comfort.

  • Remodeling tip: Windows to the north will benefit the most from better insulated windows because they are always in cool shade. Low-e coatings, argon gas fill and thermally-broken frames will improve efficiency and make the windows less chilly. 

Eastern exposures: Eastern light is direct in the mornings, making it ideal for sleeping spaces and breakfast nooks where people spend time early in the day. Morning sunlight can have a positive effect on mood, reducing depression and anxiety. As with western exposures, glare and unwanted heat gain can be an issue when sun angles are low in the hours after sunrise, and vertical sun shades on the exterior are more beneficial on western facades than horizontal shades.  Eastern light is warm in the mornings and cool in the evenings, creating variable light and color quality as does western light. Temperatures will also be warmer in the mornings and cooler in the evenings, making east-facing rooms ideal for sleeping. 

  • Best spaces/activities for east-facing windows: Bedrooms, breakfast nooks, spaces used in the morning. 

  • Worst spaces/activities for east-facing windows: Spaces that cannot tolerate variable light. 

  • Best paint colors: Variable depending on time of day the space is primarily used. Morning light tends to be soft, while evening light can feel cool and less bright. If the space is used in the evening, consider a warm, saturated color palette. Cool and neutral tones are suitable for spaces used in the mornings. Blue in particular can be soothing and pleasant in an east-facing bedroom. 

  • Decorating tip: Eastern exposures are all about the morning, so consider taking your breakfast near an east-facing window or placing your yoga mat or exercise equipment in an east-facing room for an early morning practice. 

  • Remodeling tip: Vertical sun shades and vertical exterior plants/trees can help filter light better than interior blinds, which block views and limit light availability. No exterior shading is necessary if morning heat gain and/or glare is not an issue.

Western exposures: Western light is direct in the evenings often causing glare and heat gain issues in the hours before sunset as the lowered sun angle renders many shading strategies inefficient or ineffective. Vertical sun shades on the exterior are more beneficial on western facades than horizontal shades for this reason, as spaces may overheat in the evenings. Because western light is variable, it is difficult to control for tasks that require more even lighting (such as work and reading spaces). It is also a poor choice for areas with TVs and computer monitors, as glare makes screens harder to see, and most people look at screens primarily in the evenings in their homes. If you enjoy waking up with the sun, a west-facing bedroom may not be ideal, as your windows will be shaded. Western light is cool in the mornings and warm in the evenings, meaning that the color and light quality will vary throughout the day. Warm evening light from the west can penetrate deep into spaces and create interesting shadows. West-facing rooms also get good light in the afternoon. 

  • Best spaces/activities for west-facing windows: Rooms used primarily in the afternoons, such as living rooms. 

  • Worst spaces/activities for north-facing windows: Spaces that cannot tolerate variable light. Kitchens used in the evenings may have overheating and glare issues with west-facing light. Bedrooms since it is darker in the morning.

  • Best paint colors: Variable depending on time of day the space is primarily used. Morning light tends to be gray and shady and more suitable for saturated colors, afternoon light is warm and comfortable, and evening light is very warm and golden and sometimes pink tinted. Warm tones for spaces used in the mornings, cool or neutral tones for those used in the evenings.

  • Decorating tip: Afternoon activities are perfect for 

  • Remodeling tip: As with east-facing windows, vertical sun shades and vertical exterior plants/trees can help filter light better than interior blinds, which block views and limit light availability. No exterior shading is necessary if evening heat gain and/or glare is not an issue.

It's also important to consider that light on two more sides will help light quality to feel more balanced and is better for a light, ambient quality of light. A corner window with light from two sides where light is concentrated in the corner of a space will be less balanced than a room with large windows on opposite sides, but multiple windows always helps. If you have one big window on just one side of a room, it can make the space feel cavernous. Try balancing the dark wall with light paint colors, mirrors and electrical lighting.

How can you maximize orientation in your existing home? If you only have access to daylight from one side, as in a typical apartment, you are stuck with the orientation you have, but you can consider colors and scheduling your day around the sun (morning yoga practice will be more appropriate if you only have east-facing windows, for example). If you live in a complex, you might ask to move to a south-facing apartment if one becomes available. If you live in a house, you may have some flexibility about which activities you locate in which rooms. If you have flexible rooms (e.g. multiple bedrooms with one to use as a home office), consider their orientation when dedicating uses. For example, a hobby room used primarily in the evenings would be better suited to a west-facing room, while a bedroom would be better suited to an east-facing room. Keep in mind the above tips and guidelines when laying out how you will use your spaces. The above tips might not be relevant to every individual, so be practical about how you use your spaces at what times of the day.