Window Life-Cycle Cost Calculations
Part 1: Justifying a Maintenance Budget for Windows
Part 3: Window Product Showcase
Justifying a Maintenance Budget for Windows
By James Piper, P.E. - March 2010 - Windows & Exterior Walls
Windows are one of those building components that everyone looks at every day, without really seeing them. As one of the most important components in maintaining the integrity of a building envelope, windows should be inspected at least once each year. But in reality, few organizations pay any attention to windows until something goes wrong.
This neglect makes no financial sense. Windows represent a major investment and they are expected to remain in place for 30 years or more. During that time, they are exposed to extreme weather conditions. The temperature differential across the window, depending on the climate, can easily exceed 50 degrees. Over a 24-hour period, the exterior window components are subjected to typical temperature swings of 30 degrees or more.
But windows seldom receive the maintenance attention they require. The result is slowly developing problems with leakage, hardware, finish, and even security. Neglected long enough, a relatively low-cost maintenance issue develops into a costly and disruptive replacement program.
To top management, however, window maintenance means little more than cleaning windows. In part because manufacturers have done a good job of improving the performance and service life of windows, windows are simply expected to perform well over a long service life with little attention. That lack of understanding of window maintenance requirements is one big obstacle to justifying a maintenance budget for windows.
Impact of Investments
The challenge for facility managers is to show the impact of neglected maintenance on the life cycle costs of windows. For years, facility managers have used life-cycle cost analysis to justify purchase decisions. But it is also used to support maintenance expenditures. If a certain level of maintenance funding can be shown to significantly increase service life, top management is more likely to approve that funding than if a facility manager simply stated that more maintenance funds were needed.
When evaluating window options, life-cycle cost analysis takes into consideration such factors as initial purchase and installation costs, maintenance costs, impact on energy costs, impact on other operating costs, and disposal costs. To win funding for window replacement or maintenance programs, facility managers should evaluate other factors as well.
Typical problems common to all types of windows include water and air leaks, failed caulking or gaskets, defective hardware, condensation and fogged glazings. For wood windows, rot and peeling paint are major issues. For metal windows, it is corrosion and failed finishes. For operable windows, it is binding, shifting, or swelling of window components that make it difficult or impossible to open the windows. For any window, even something as simple as plugged weep holes can result in water leaking into the building or damaging window components.
Each of these issues, left uncorrected, will result in a decrease in the service life of the window. While it is easy to understand that spending maintenance funds now can delay the time when money will have to be spent on window replacement, simply presenting that argument to top management will not be sufficient. Facility managers are competing with other managers for limited funding, particularly during tight economic times. This is where a thorough life-cycle cost analysis will help build and quantify the case for spending on window maintenance or replacement.
Life-cycle cost analysis can be applied to justify on-going maintenance costs as well as window replacement costs. While the two approaches are similar, there are some differences in cost factors that must be considered.