Great news. On my day off I decided to do a spot of bird watching in my garden and discovered that we have a resident blackcap male. Now will get looking for the female. We seem to have had a pair nesting every year for the past 3 years. The BTO are currently undertaking a blackcap survey nationally, so will add my data and feel happy that a little bit of info may help to go a long way :)
http://www.bto.org/volunteer-surveys/gbw/about/background/projects/garden_blackcap_survey