Howell Carr Lewis Jr., 78, a retired official of the Federal Housing Administration who retired in 1962 as a lieutenant colonel in the Army Reserve, died Thursday at Northern Virginia Doctors Hospital after a heart attack. He was a resident of Arlington.

He worked for the FHA for 25 years before retiring in the early 1970s as assistant chief architect in its district insuring office. He was a ntive of Ivy, Va., and was a gradutate of Wittenberg University in Springfield, Ohio. Col. Lewis came to this area in the 1930s. He was a civilian engineer with the Navy's Bureau of Yards and Docks before serving as an Army officer in Europe during World War II.

Col. Lewis was a life member of the Military Order of the World Wars and the Retired Officers Association, and a member of the Society of American Military Engineers, the National Society of Professional Engineers and the Society of the Cincinnati of Virginia. He was a life member of the National Rifle Association. He was a member of Trinity Episcopal Church in Arlington.

His first marriage, to the former Helen Hammond, ended in divorce.

Col. Lewis' survivors include his wife of 44 years, the former Mary Tayloe Newton of Arlington; a son by his first marriage, Lynn Hammond Knapp of Holliston, Mass.; three sons by his second marriage, Howell C. III of Berryville, Va., Tayloe Newton Lewis of Alexandria and Fielding Tyler Lewis of Manassas; a daughter by his second marriage, Reid Lewis Jeffries of Arlington; two sisters, Elizabeth L. Bowen of Charlottesville and Catherine L. Grasty of Orange, Va., and six grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the Westmoreland County Rescue Squad in Mount Holly, Va., or a charity of one's choice.