If you’re like most people, you spend about 90% of your days indoors. And, on the coldest days of winter or hottest dog days of summer, it can be even more. But, humans evolved mostly outdoors, so what happens when we spend so many hours inside? We get less fresh air (and indoor air quality is typically 2-5 times more polluted than outdoors). We get less time in nature (which has been shown to have a multitude of benefits for health and well-being). And, we get less time basking in the rays of the sun. Over the past couple of decades, the main public health message regarding sunshine has been focused on ensuring people don’t spend too much time in the sun in order to reduce the risk of skin cancer. But an increasing body of evidence shows a litany of negative health effects when we don’t get enough. That’s exactly why sustainable home design (which focuses as much on the health of inhabitants as it does on the health of the planet) includes maximizing natural lighting. But that’s not the only benefit of inviting in some sunshine, here are 5 reasons you need as much natural lighting in your home as possible.

#1 NATURAL LIGHTING SAVES ENERGY AND MONEY

This one’s pretty obvious, but it’s worth saying anyway. Strategic natural lighting can reduce energy costs because it can help heat or brighten a space without using electricity. 

#2 NATURAL LIGHTING INCREASES FOCUS

Natural light during both the morning and evening has been shown to increase concentration and focus. Feeling foggy? Try looking out the window and soaking up the sun for a few minutes for a boost of alertness. Having enough natural light is especially important if you work from a home office. A naturally lit space will help you be more productive than an artificially lit work environment. Increased natural light during the day helps you sleep better, so that you’re well-rested and on the ball for work the next day.

#3 NATURAL LIGHTING REDUCES BLOOD PRESSURE

Research shows that sunlight alters levels of the small messenger molecule, nitric oxide (NO) in the skin and blood, which reduces blood pressure. Martin Feelisch, Professor of Experimental Medicine and Integrative Biology at the University of Southampton, says “NO along with its breakdown products, known to be abundant in skin, is involved in the regulation of blood pressure. When exposed to sunlight, small amounts of NO are transferred from the skin to the circulation, lowering blood vessel tone; as blood pressure drops, so does the risk of heart attack and stroke.”

#4 NATURAL LIGHTING REDUCES STRESS AND ANXIETY

Feeling wound up? Bask in natural daylight for 30 minutes every morning to create an inner calm. ”If people are exposed to light in the morning that mimics the wavelengths of daylight, they become better at coping with anxiety-provoking experiences. The light simply improves the communication between the regions of the brain that are central to our handling of emotions such as stress and anxiety,” says PhD fellow Brenda MC Mahon, MD, of the Neurobiology Research Unit at the Copenhagen University Hospital, Denmark.

#5 NATURAL LIGHTING GIVES YOU MORE ENERGY

Melatonin is a hormone that regulates sleep and makes us tired. Sunlight slows down our body’s ability to make it (that’s why we’re naturally sleepy at night and awake during the day). Allow yourself to sync up with nature’s clock in order to set a steady circadian rhythm for yourself. By getting enough natural light, your body’s inner clock will get on track, giving you a better night’s sleep and more energy during the day.