Windows and Glass in the New Green Building Guidelines

Windows and GlassANSI, ASHRAE, The US Green Building Council, along with other agencies, recently released the 2014 version of the standards for green buildings.

The “Standard for the Design of High-Performance, Green Buildings Except Low-Rise Residential Buildings,” or Standard 189.1-2014 includes new standards on site sustainability, water use and energy efficiency, and indoor environmental quality, among others.

Energy Efficiency and Glass

One interesting part of the new code is the implications and revised requirements regarding glass and fenestration in buildings. This involves setting new recommendations for envelope requirements, including windows.

In essence, the new standards say buildings will need to use more energy efficient materials. For the windows, for example, it’s not enough to have toughened glass; it also needs to be sustainable and energy-efficient.

Glass windows account for the majority of heat loss in a building, which is why windows went from single-pane glass in the old days to double- and even triple-pane units. As Optical Coatings puts it, various coatings applied to glass significantly boost energy efficiency. It also offers a number of benefits in terms of aesthetics.


Fenestration, or the openings in the walls of a building or structure, is also regulated in the new standards. Orientation requirements are updated with guidelines based on new research. There are also changes in equipment efficiency tables and Energy Star references.

This just means there are new recommendations in the type of wall opening, materials, and designs you plan for your building. The recommendations take into account the overall energy performance of a structure.

Environmental Impact

There are also updated requirements regarding the impact of building constructions on the atmosphere, materials, and resources. Basically, from the planning, construction, to operation, every aspect of a building should be eco-friendly, sustainable, and compliant with industry standards. The updates include better construction waste management, life-cycle assessment, and multiple-attribute product declaration or certification.

With the ever growing threat of climate change and the depletion of resources becoming more ominous, everyone is expected to do their part and help in further reducing negative energy and environmental impacts.