He designed many of the well known public building in Perth and Fremantle and was President of the Western Australian Institute of Architects from 1909 ro 1911.
Hobbs also had a distinguished military career, seeing action in Egypt, Gallipoli and France during World War I. Originally an artillery commander, he briefly commanded the Australian 1st Division at Gallipoli. On January 1, 1917 he was promoted to major general and took command of the Australian 5th Division. He attained the rank of lieutenant general and was created Knight Commander of the Bath (KCB) in 1918 and Knight Commander of St Michael and St George (KCMG) in 1919.
After the armistice Hobbs decided to return to his former profession, architecture. With a keen interest in the construction of war memorials Hobbs was responsible for designing the West Australian War Memorial in Kings Park, Perth.
He died of a heart attack while en route to the unveiling of a war memorial built to his design at Villers-Bretonneux, a French town recaptured under his command in World War I.