Is there an elevator mezzanine in the residential building

There may be. The mezzanine is a platform on the elevator shaft, which is located between each floor. The mezzanine can be used as a safe passage for passengers to evacuate in case of elevator failure or emergency during operation. Passengers can wait for rescue in the mezzanine or evacuate safely through the mezzanine to avoid being trapped in the elevator car. In some communities, there will be elevator mezzanine, because there is no mandatory provision, so there are also some communities that are not equipped with elevator mezzanine during construction. So residential buildings may have elevator mezzanines.