Window replacement isn’t cheap, but neither are existing windows that are out of date and inefficient. The opportunity to upgrade comes around infrequently – possibly as part of a broader energy conservation plan
funded by one financial package – so owners must
maximize their return.
“Windows are an important contributor to the building envelope and can be an integral part of energy conservation strategies,” explains Kerry Haglund, Research Fellow
for the Center for Sustainable Building Research at the University of Minnesota, in
his report “Window Selection Methodologies and Optimization in High-Performance
Commercial Buildings.” In fact, the report estimates that 39% of commercial heating
energy use and 28% of commercial cooling energy use – 34% of all commercial space
conditioning energy use – are attributable to windows (excluding infiltration).
Fortunately, improvements in window technology have greatly improved the performance of window and glazing systems. Today’s windows have lower heat loss, less air
leakage and warmer surfaces that help to improve occupant comfort while minimizing
condensation. With features such as double- or triple-glazed insulated glass, improved
frames and specialized coatings and films, these high-performance windows are effective at reducing heat transfer.
To make a positive investment in a window upgrade, building owners and facility
managers should be familiar with specifications, performance measurements, costs and
BY ROBERT NIEMINEN, CONTRIBUTING EDITOR
The investment is substantial, but the benefits of energy-efficient windows
outweigh the costs
from WINDOW UPGRADES