Link to Article
Overall, I agree with the article - operating costs will certainly be higher but you'll see that on day one. There are some interesting numbers in the article related to the lifespan of windows. A number of 25 years is suggested. That seems a bit short to me - the commercial building I work in is 40 years old and while it's certainly not as efficient as newer buildings I've worked in - it hasn't completely failed. Of course, quality of the glass, and the contractor doing the installation has a tremendous impact on overall life.
So what does that mean for reserve fund reports in buildings with glass curtain walls? Consult an expert is always your first step of course. After that it'll be a question of judgement and reasonability. If your reserve fund report has 100 years listed for exterior glass - that's probably too long. Same with 75 years. 15 years? Probably too short. At the end of the day, glass curtain walls become yet another item in the reserve fund report for you to scrutinize: 1) the cost to replace and 2) estimate the lifespan.