Complex sentence: The small country house, now a Grade II listed conference centre, was built in the 1860's for Hugh Hammersley, and then extended 1884-6 by the architect George Devey.
Split into simpler sentences: The small country house, now a Grade II listed conference centre. Was built in 1860's for Hugh Hammersley, and then extended 1884-6 by the architect George Devey.