Complex sentence: The building is an example of contemporary technical innovations in relation to electricity, since it was the city's first machine shop and was the fourth in the city who was a phone, which is seen on the gable, which is advertised for it.
Split into simpler sentences: The building is an example of contemporary technical innovations in relation to electricity. Since it was the city's first machine shop and was the fourth in the city to have a phone, which is seen on the gable, which is advertised for it.