This year, we’ve been talking a lot about Why Windows Matter. NFRC has an ongoing campaign centered around it, to combat the notion that fewer or smaller windows are the answer to energy efficiency. As we’ve seen so far, this short-sighted “solution” doesn’t account for a host of benefits from windows, including occupant comfort, the fact that there are ratings available that take the guesswork out of the window’s contribution to the building’s efficiency, and more to come.

This month, I fully intended to focus on the benefits of windows on physical health. And there are benefits – exposure to sunlight may lower blood pressure, assist the immune system, prompt the body to make vitamin D (the benefits of which are still being discovered and confirmed), ventilation and access to fresh air is of particular focus during the time of COVID, etc. – but we also have a challenge.

While the benefits of ventilation and access to fresh air aren’t affected, the low-E coating on the vast majority of modern windows (an estimated 83% of residential windows) may block some of the physical benefits associated with sunlight. With ultraviolet B (UVB) light blocked by the glass, the benefit of sunlight on the skin for vitamin D production is reduced so we can’t tout that as a benefit of sitting at the window.

Still, there are benefits from the removal of ultraviolet radiation though and, as an industry, we can certainly focus on that. Low-e glass reduces UVA damage by 75%, according to LBNL. UV light is associated with damage to the body, down to the DNA, and limiting exposure to both UVA and UVB radiation is recommended for skin cancer prevention.

The benefits of limiting UV radiation in the home extends beyond the human body, of course. There are financial benefits with the preservation of artwork, furnishings, and textiles in the home.

Next month, I will focus on the mental health benefits of windows as part of the Why Windows Matter campaign. Educating the consumer on the importance of being able to enjoy a view and sunlight while reducing the potentially negative effects of ultraviolet radiation, is all part of the formula for combating the anti-window crowd while convincing consumers that they can be happier, healthier, and more comfortable in their own homes.