Barker then went on to operate an architectural practice in Carlton from 1969 to 1971, as well as working as a consultant for project home builders.
Barker was the first Director to act in a full time capacity, as there was expanding demand from the public for homebuilding advice.
Barker also established the Architects Renovator Service, which operated successfully through the Victorian Chapter of the RAIA.
In 1979, Barker stepped down from his position as Director to work in his own practice, his main interest being residential and renovation projects.
In 1980, Barker published the book "Renovate: architectural concepts for rejuvenating houses and building" Circa 1990, Barker was the Victorian State Manager of Archicentre (now defunct), the building advisory service of the Royal Australian Institute of Architects.