The three important baroque buildings were renovated with a total investment of around 28 million euro. The six to seven storey buildings house shops, restaurants, offices and apartments. Their versatile use also requires versatile electrical installation. Therefore, the long-lasting and durable products from Spelsberg’s IBT programme were used for the renovation. For example, switches and connector sockets are installed in concrete walls and ceilings. They enable boxes and receptacles to be strung together by means of a uniform grid dimension, whereby many switches and boxes can be installed as required.