I am pleased with your inquiry, and happy that your dad survived the war.
Shelby L. Stanton's "WW II ORDER of BATTLE", provides the following:
Unit activated 17 Dec 43, at Camp Carson, CO: departed US 4 Sep 44; arrived England, 15 Sep 44; landed in France-ETO, 4 Oct 44; crossed into Belgium, 27 Oct 44; entered Holland, 6 Nov 44; entered Germany, 6 Feb 45, where inactivated 12 Nov 45.
Location at war's end, 15 Aug 45, Ober Ingelheim, Germany.
Stanton only lists two campaigns, Rhineland and Central Europe, so Mr. Pennington must have served with another unit prior to the 1149th ECG to have qualified for Normandy and Northern Europe as well.
I suspect that he campaigned with one or more of the Combat Engineer Batalions before his assignment to the 1149th ECG.