Why Do Windows Matter?
30%
How much energy is used to heat and cool a building due to heat escaping and entering through windows
1 gigaton
The amount of annual carbon dioxide emissions from energy losses through windows — roughly the same amount as the emissions from the entire aviation sector
$40 billion
Annual cost of heat losses through windows
A Partner’s Perspective Peter Gajdoš, partner and co-lead of Climate at Fifth Wall, provides insight on solar and smart windows.
Why are windows important to discuss in a conversation about climate change solutions?
About 30% of energy in buildings is lost through windows as opposed to walls or roofs. Glass is a terrible insulator.
What are some non-glass options to consider when building windows?
Well, you can obviously go for smaller windows or no windows, but that’s often not acceptable from an architectural standpoint. There are other materials such as plexiglass or polycarbonate plastic, but glass is typically a pretty abundant, cost effective material. The idea is to improve on the glass material performance itself. This could mean tapping into low emissivity coatings, vacuum-insulated glass, double or triple pane windows, blinds or electrochromic layers.
Why are solar windows and smart windows better than glass?
Solar windows — potentially valuable in high rises where rooftop solar space is limited — allow for partial energy energy production for the building. Smart windows have lower energy usage, better payback, more efficiency, better cooling and shading. Windows of the next generation need to automatically adjust to changing conditions during the day and during the seasons.
What hurdles might someone face when integrating alternative windows into construction plans?
For starters, the cost is very expensive. The installation can be increasingly complex, too, which ties into cost but also means spending more time with less reliability with wiring and additional layers. The lack of insurability also makes integrating alternative windows difficult. These novel materials need proper certification and insurance, and it’s hard to make them bankable. There’s also an issue with lack of experience. Installers and construction crews may not be familiar with the new windows. It’s important to get buy-in from various stakeholders — architects, developers, multiple building owners, and tenants, for example.
