Twilight Indoors: Are Our Buildings Making Us Sick? – Ep 115 with Jan Denneman

2025-12-03

Download

This week on Better Buildings for Humans, host Joe Menchefski explores the fascinating science of light and health with Jan Denneman, founder of the Good Light Group and a 45-year veteran of the lighting industry. Jan unpacks the critical—yet often overlooked—role of light in regulating our circadian rhythms, boosting sleep quality, enhancing mood, and even reducing national healthcare costs. From the newly discovered “spheres” in our eyes to the magic of 500 lux, Jan explains how most indoor environments fall into what he...

This week on Better Buildings for Humans, host Joe Menchefski explores the fascinating science of light and health with Jan Denneman, founder of the Good Light Group and a 45-year veteran of the lighting industry. Jan unpacks the critical—yet often overlooked—role of light in regulating our circadian rhythms, boosting sleep quality, enhancing mood, and even reducing national healthcare costs. From the newly discovered “spheres” in our eyes to the magic of 500 lux, Jan explains how most indoor environments fall into what he calls a “twilight zone,” biologically speaking. He also dives into why natural light trumps artificial, and how healthier buildings could be our biggest untapped wellness tool. If you care about human-centered design, lighting innovation, and boosting occupant performance, this episode is a must-listen.

More About Jan Denneman

Jan Denneman is the founder and chairman of the Good Light Group and ambassador of the Global Lighting Association. The Good Light Group is a non-profit organization promoting good indoor lighting — either natural daylight or electric light with comparable positive effects on health and well-being. Good light helps synchronize the biological clock, improves sleep quality, increases daytime energy, and supports a better mood and long-term health. With more than 45 years of experience in lighting,

Jan has developed deep expertise in how light affects human health. He served as Vice President at Philips Lighting (now Signify) and held leadership roles in innovation, product development, marketing, and sustainability. Jan co-founded several leading international consortia, including: Global Lighting Association (Chairman 2007–2017), Zhaga Consortium, The Connected Lighting Alliance, LightingEurope (Chairman 2013–2017), Good Light Group (Chairman since 2019) Jan shares his expertise on healthy lighting and sleep through short videos on Instagram, TikTok, YouTube, and Facebook

Contact:

https://www.linkedin.com/in/jan-denneman-a60bb57/?originalSubdomain=nl

https://www.jandenneman.com/

https://www.goodlightgroup.org/

https://globallightingassociation.org/

Where To Find Us:

https://bbfhpod.advancedglazings.com/

www.advancedglazings.com

https://www.linkedin.com/company/better-buildings-for-humans-podcast

www.linkedin.com/in/advanced-glazings-ltd-848b4625

https://twitter.com/bbfhpod

https://twitter.com/Solera_Daylight