Circadian Locations 🗺

🪶 Do you need to relocate to achieve circadian rhythmicity?

Hi,

Do you need to move to achieve circadian rhythmicity? Depending on where you live, the answer may be yes!

The long horizons of the ocean are great for soaking up morning and evening light cues. This beautiful photo is from Sides Imagery.

Last week, I shared research about entrainment, which is the biological process of aligning with the external environment. In case you didn’t have the chance to check out that paper about entrainment, here it is again: Entrainment of the Human Circadian Clock (2007). In this paper, the authors shared the finding that people in urban locations tend to have a later chronotype on average than those in rural locations. The authors speculate that this is caused by less solar exposure. This made me want to go back to what we know about how to make homes and locations more friendly to our biology.

Here is what we know about circadian locations:

• Prefer rural, non-obstructed locations rather than crowded urban ones. This reduces shading and noise (and other) disturbances.

• Choose settings with brighter, rather than darker, exterior elements. This increases the indirect light that can enter the space. This means the bottom of a north-facing canyon is not the best location, even if it is remote.

• Choose settings that make you want to go outside (the sun is the main source of entrainment).

Here is what we know about circadian architecture:

• Design single-story rather than multi-story buildings.

• Build shallower, rather than deeper, floor plans.

• Place windows high to catch summer light and low to catch winter light.

• Place windows to receive lighting across the day (pay special attention to the East/morning and South/afternoon).

• Whenever possible, favor daylight over electrical light.

Here is what we know about interior design:

• Remove exterior elements that block sunlight from the windows.

• Move furniture and workstations closer to windows. Face things so eyes point towards (or perpendicular to) windows.

• Use blinds instead of glazes to reduce glare.

• Cover walls with neutral tones and reflective paint to increase indirect light.

• Install overhead lights (choose bright ones, like the sun!).

• Use blackout curtains to block outdoor artificial light from coming in at night.

• Use night-specific lights with red/amber tones and low lux. Install them at eye-height or below. To prevent melatonin suppression, use <10 lux for the 3 pre-bedtime hours and <1 lx for sleep (think candlelight tones).

Read the research yourself

All of these tips are outlined in much greater detail and in the context of research that has been done in this review: Role of Architectural Design in Creating Circadian-Effective Interior Settings (2021).

Role Of Architechtural Design In Circadian Effective Interior Settings

1.42MB ∙ PDF File

Read now

This paper reviews essential architectural design parameters and their impacts on circadian lighting design, considers the Human Centric Lighting design process and explores the most widely used circadian lighting metrics and standards.

Read now

Also, in case you missed it, I first shared this Energies article here:

Home Sweet Circadian Home🏡

And I also recommend you read the article, Melatonin and stable circadian rhythms optimize maternal, placental and fetal physiology (2013), which I first cited in the post below if you need a refresher (or introduction) to how integral darkness and melatonin are to our wellbeing.

Rhythmicity from the start👶

That's all for today, but you can always review past posts at nikkofujita.substack.com/archive. What do you think about these home design tips? Do they give you any ideas for making your living space more circadian-effective? Let us know in the comments!

Best,

Nikko