Working at The Guinness Partnership today. By Guinnessâs centenary in 1989, we managed 10,000 homes, and over the next 20 years were joined by 12 other registered providers, including Hermitage Housing in 2002, Midsummer in 2006 and Northern Counties in 2007.orking at The Guinness Partnership today. By Guinnessâs centenary in 1989, we managed 10,000 homes, and over the next 20 years were joined by 12 other registered providers, including Hermitage Housing in 2002, Midsummer in 2006 and Northern Counties in 2007.