THE FLT ORIGINATED AT ALBANY, NY & CONTINUED TO SARATOGA, NY. PROVINCETOWN, MA, HYANNIS, MA, THEN RETURNED TO SARATOGA. THE TOTAL FLT TIME WAS APRX 3 HRS & WAS CONDUCTED USING FUEL SOLELY FROM THE LEFT FUEL TANK. THE APCH TO SARATOGA WAS FROM THE SOUTHEAST. DURING AN ENTRY TO A RIGHT BASE LEG, THE PLT MADE A SHALLOW LEFT TURN, THEN FOLLOWED THIS BY A SHARPER RIGHT TURN ONTO FINAL APCH. AT THIS POINT, THE ACFT WAS SOMEWHAT LOW, SO THE PLT ADVANCED THE THROTTLE, BUT THE ENG LOST POWER. THE PLT ATTEMPTED TO RESTART THE ENG, BUT WAS UNABLE. SUBSEQUENTLY, THE ACFT COLLIDED WITH TREES & A HOUSE DURING AN EMERGENCY LANDING. BOTH OCCUPANTS RECEIVED HEAD INJURIERS. THE ACFT WAS NOT EQUIPPED WITH SHOULDER HARNESSES. AN EXAM REVEALED NO EVIDENCE OF A PREIMPACT, MECHANICAL PROBLEM. THE ACFT WAS PLACARDED: 'TURNING TYPE TAKEOFFS, & TAKEOFF IMMEDIATELY FOLLOWING FAST TAXI TURN PROHIBITED. AVOID PROLONGED SLIPS (20 SECONDS OR MORE) WITH FUEL TANKS LESS THAN HALF FULL.'