02/17/2026
Most modern office buildings are accidentally blocking their own cell service.
The culprit? Low-E glass.
Low-emissivity (Low-E) glass is fantastic for energy efficiency. It reflects infrared heat, lowers utility costs, and helps buildings meet modern efficiency standards.
But here’s what most developers and business owners don’t realize:
The same metallic coating that reflects heat also reflects and attenuates RF signals.
That includes:
• 4G LTE
• 5G
• First responder bands
• Standard voice calls
So you end up with a beautiful, energy-efficient building… where no one can get a signal near the windows.
In older buildings, signals would pe*****te fairly easily. In newer construction with Low-E glass and energy-efficient materials, signal loss can be dramatic — sometimes 20–40 dB or more depending on coating type and frequency.
What does that mean in real terms?
• Dropped calls
• Missed texts
• Poor data speeds
• Employees walking outside to take meetings
• Tenants complaining
• First responder communication issues
And here’s the hard truth: carriers aren’t going to fix this for you. From their perspective, coverage is fine — outside.
This is becoming one of the most common causes of indoor cellular issues in modern offices, healthcare facilities, schools, and commercial buildings.
If you’re designing, renovating, or managing a newer building and noticing signal problems, Low-E glass might be part of the equation.
Energy efficiency is great. But communication reliability is non-negotiable.
If you want to test your building’s signal performance or understand mitigation options (DAS, signal boosters, distributed antenna systems), happy to talk.