Athéna's getting renovated in la Défense...
http://tourathena.fr/index_uk.html
The original glass curtain is not even really old yet (1984) and looks okay:
pss-archi.eu
Work on it is beginning right now.
There's a war on energy consumption in la Défense, the local market is getting harsh in that respect. Hope they don't change what's getting a little old but still looks really good. That'd be nuts!