Bingo, found it!
He was Clerk of Works for the Police Offices extension to the rather magnificent Law Courts in Corporation Street, built by your very own John Bowen.
The extension was added in 1894, in the same style as the original, with a large bay window. The architects were Ingress Bell and Aston Webb, who also designed the Stafford General Infirmary and the Victoria and Albert Museum in Kensington which my Great Grandfather was also Clerk of Works for.
Tried to attach photos of the article which appeared in the Police Chronicle 24 Feb 1894 but files are too large! It states: "The work is being carried out under the superintendence of Mr H W G Tanner, the efficient clerk of the works" - Birmingham Daily Post.
Don't know if the attached photo is very clear but he is seated in the centre of the workmen holding the address he read to King Edward VII at the opening of the V&A in 1909.
Many thanks for your help in locating his address whilst living in Balsall Heath
Maddy