Now purchasing or making a full set of Gryffindor robes was out of the question ( for financial and time reasons). So I decided instead to take a plain black graduation robe and make a few modifications.
I first got 2 yards of fabric ( black and red). I cut a large isosceles triangle out of both colors. Placing them one on top of the other I then cut the top of the triangle so it was curved instead of pointed. Then fused them together with liquid stitch, leaving one corner open.
I turned the triangle inside out, and then tacked it over the shoulders of the robe so it would lie like a hood ( although non functioning)
Then I searched the internet for an image of the Gryffindor House patch. I printed it onto an Avery Ink Jet Dark T-Shirt Transfer sheet. I then ironed the transfer sheet onto a piece of black felt, cut it out and hand stitched it to the robe.
After that was finished it was just a matter of getting a plain grey pull over cardigan. To that we added a pair of round rimmed glasses that I already had in my costume stash, my husband's own pair of slacks, black shoes and white dress shirt, a Gryffindor tie we borrowed from a friend and the wand I made him.