I've read that the Eiffel Tower was intended as a temporary attraction for the 1889 World’s Fair and then it was supposed to have been dismantled. I've always wondered, if they had known it was going to become permanent, would they have built it differently? (For example, a stronger foundation, rust resistant materials or finishes, etc.)
I'm also curious about the same thing in regards to the London Eye.
This seems like a hypothetical question, so unless somebody has the diary of Gustave, don't expect a complete answer.
What one could assume is that yes, the design might have been different. Buildings (and by extension ideas) are rarely thought up in thin air, and are usual a product of their environment and what restrictions are given. If Eiffel had known that his tower would have to stand the test of time, then by all means he would try to achieve that goal.
I did some calculations on the cost of the Eiffel tower because I couldn't find good data on it. I obtained an estimated cost during construction of 6.5 million francs in 1887. Given that in 1873, the franc was set to a gold standard, and that historical prices for gold can be obtained in USD (because its very difficult to get data on the franc) I assumed I could convert 1873 francs to 1873 USD (which came out to 56.53 francs = 1 USD in 1873) and then converted 1873 USD to 2014 USD, I came up with "What cost $114973.16 in 1873 would cost $2239791.93 in 2014."
I'm not sure that this says much, but if anyone was wondering how much money was put into the tower during construction, that might be a good estimate.
One way to determine this is to see what has had to be done since construction to ensure it lasts; if any corners were cut during construction, surely those would have been rectified since. Essentially, other than some first-floor rehab to make it more functional as a tourist spot, it seems that the only major conservation work is to paint it on a regular basis. Interestingly it has had a number of colors over the years, from red to yellow to brown.
For example, could it have been built significantly taller (say 2 times) with the technologies at the time?
Similar thing could be said for the Atomium (no image allowed because of copyright), it was only supposed to last for the world exhibition of 1958. They decided to keep it, and they restored it in 2006. Lots of details will show that it wasn't supposed to stand so long (with sidepanels that don't align properly etc, but it's still safe)
Follow up question.
Did any change in the structure of the tower (reinforcements) was made when they decided not to dismount it?