He was known after he drew up plans for University of Santo Tomas (UST) Main Building, the first earthquake-shock resistant building in Asia,[2] which was constructed at the Sulucan property of the Dominican order in city of Manila.
He transferred to the University of Santo Tomas and was able to obtain a Doctorate in Civil Engineering.
As a proof, he was the builder of the Dominican Residences in Baguio and Lingayen, Pangasinan.
Ruaño was also a professor in the then-School of Civil Engineering of the University of Santo Tomas.
[1][3] The good prelate engineer died on March 1, 1935, due to heart failure.