There’s usually a good reason the bld mngt dosn’t want you to have a key,(security,fire,environmental conditions just to name a few).I would check with mngt and ask for their reasoning for having the windows locked.I work in building maintenance for our local college and we don’t allow employes to open the windows in our admin blg because it unbalances our central hvac system,which makes more people uncomfortable than help those who want the fresh air.