The aircraft, with a solo Student Pilot on board, was carrying out circuit training at Waterford Airport (EIWF). As the aircraft commenced a turn onto the base-leg of its first circuit, the engine began to vibrate violently, lost power, and did not respond to throttle inputs. On final approach to Runway (RWY) 21, the Student Pilot declared an emergency (Mayday), and informed EIWF Air Traffic Control (ATC) that he was carrying out a forced landing. The aircraft touched down in a field, bounced, and continued through a boundary hedge. The aircraft came to rest, inverted, in the adjacent field. The Student Pilot exited the aircraft uninjured. The aircraft sustained substantial damage. There was no fire.