An elevator system for traveling on a rail attached to the outside of a high-rise building. One elevator having a telescoping arm attached for reaching any position on or above the building. A platform or cabin attached to the telescoping arm can deliver materials to the building while under construction and thereafter be used for building maintenance such as window washing. The movable platform adjacent a building can take the place of scaffolding for a safer work environment. The telescoping arm may have various attachments for different functions such as for rescuing people trapped in a high-rise during a fire or for positioning fire fighters and hoses or fire fighting equipment next to a fire. The elevators may be raised and lowered by motors connected to cables or under their own power.