When Sir Josiah Eccles presented his report on the running of the Electricity Supply Industry in Northern Ireland in 1963, his main recommendation was the formation of a body to 'maintain detailed control of production and main transmission that will secure the maximum economy consistent with security of supply.'

In 1968 the Northern Ireland Joint Electricity Authority (NIJEA) was established, taking over responsibility for generation and transmission from Belfast Corporation Electricity Department (BCED), the Electricity Board for Northern Ireland (EBNI) and Londonderry Corporation Electricity Department (LCED). The NIJEA started life located in the old Castlereagh Presbyterian Church Hall in Church Road.

A 45 acres site surrounding Castlereagh House was obtained and in 1971 the new Castlereagh House Control Centre (CHCC) was built, just a few hundred yards from the Church Hall they had occupied for nearly 4 years. The site, set in the Castlereagh hills, is on the south-east side of Belfast and provides an excellent working environment in a beautiful rural setting.