Largest socialist state palace

The largest palace in the world used for a socialist state government and leader is the Palace of the Parliament in Bucharest, Romania, which was mostly constructed between July 1984 and 1989 during the regime of the Romanian Communist Party and its then head Nicolae Ceauşescu. Housing the two chambers of the Romanian parliament, the massively imposing neoclassical structure contains 1,100 rooms and parking spaces for 20,000 cars across a 340,000-m² (3,700,000-ft²) floor area. It measures 270 m (890 ft) by 240 m (790 ft), and rises 86 m (282 ft) above ground with another 92 m (302 ft) of subterranean levels. The palace was designed by 25-year-old architect Anca Petrescu, working with a team of more than 500 people, and was constructed by Aedificia Carpati using 20,000 workers.
At 700,000 tonnes, it is also the world's heaviest building.

In order to clear space in Bucharest for the construction of the Palace of the Parliament and the associated 5-km-long Victory of Socialism Boulevard (now Boulevard Unirii), over 30,000 homes and dozens of religious centres and other monuments were destroyed.

The building was fabricated largely of local materials. Estimates of materials used include 1 million m³ of Transylvanian marble, 3,500 tonnes of crystal for 480 chandeliers and 1,409 lights and mirrors, 700,000 tonnes of steel and bronze, 900,000 m³ of wood and 200,000 m² of woven carpets, many of which were spun on site.