You ask the first question as if "lifespan" were only a measure of how long a building might be fashionable to use, and you ask it as if you're the one in this thread with the objective answer, anyone who disagrees with you has to be wrong.
Change your tone. This thread is for discussion purposes, it's not for you to preach. You can try to convince others, but not through bullying. Another example of your tone problem on recent pages is in regard to "consensus" where you essentially state that there appears to be more who agree than those are opposed, and therefore your views must be right. Linking the two, however, is a fallacy. Sure, you may have the numbers, but that may only indicate that you've succeeding in tiring out the opposition, not convincing them. That happens when other members bump into a member who goes on and on endlessly about something. It takes time and energy to refute what someone says who's willing to go on forever, and many have better things to do with their time.
For those who do slip into endlessly going on about something, we call that trolling, and it's against the rules. Make your point, and then let the thread move on.
To the point of your first question though, most times that "lifespan of a building" is quoted, it's to describe how long a building will hold out against the elements, be safe for use, perform its intended purpose. A building may no longer be considered state-of-the-art for long after it's built, but it will likely be useful for many years after. Housing, our most ubiquitous building stock, normally last a century or longer, and much more of it gets adapted over time than gets demolished. The lifespan of major league stadiums in recent years has been far shorter than what they are actually built to endure as technologies and tastes have changed,
To the point of your last question, if stadiums weren't so tough to adapt—so much concrete and steel—we wouldn't smash wrecking balls into them, as yes, tearing down buildings does affect climate change. There is
embodied energy in anything we make, and generally the larger, tougher, and heavier the product, the more embodied energy it has, and pretty much nothing has more embodied energy than a concrete building, which requires a ton of energy be used to create it, and a ton to be expended to take it down too. Since the development industry overwhelmingly burns fossil fuels to build and to tear down/recycle, yes, buildings affect climate change. It's a big reason why many people are concerned about throwing away yet another massive stadium, and in this case, a building that may very well represent the most embodied energy in the entire city. For my part, I really hope that a good firm is hired to make the changes to the existing structure that will fix the sightline issue, bring in natural light, etc. etc., achieved through precise cuts and not wasteful, wholesale demolition.
Finally, Rogers has said they won't ask for public money, but people are very skeptical, and they have good reason to be. While this isn't the States and things aren't quite as bad here in regards to what billionaire owners have been able to prize away from the taxpayers down there, we did pay most of the cost of building SkyDome (about $420 M of the $570 M cost) before it was gifted (minus the hotel) to Rogers for only $25 M. No wonder many people don't buy that there won't be ways that the public ends up holding many of the purse strings for a new stadium.
Anyway, please tone down your posts on UrbanToronto. Discuss, don't bully.
42