According to the legal definition, Toronto-St Paul's Riding is defined as follows. Ward 12 follows this definition.
Consisting of that part of the City of Toronto described as follows: commencing at the intersection of Eglinton Avenue West and Dufferin Street; thence southerly along Dufferin Street to Rogers Road; thence easterly along said road to Oakwood Avenue; thence southerly along said avenue to Holland Park Avenue; thence easterly along said avenue to Winona Drive; thence generally southerly along said drive to Davenport Road; thence westerly along said road to Ossington Avenue; thence southerly along said avenue to the Canadian Pacific Railway; thence generally easterly along said railway to Yonge Street; thence northerly along said street to Jackes Avenue; thence easterly along said avenue to the westerly boundary of the Rosehill Reservoir; thence northerly along said boundary to Rosehill Avenue; thence easterly along said avenue and its easterly production to the Don River Tributary situated easterly of Avoca Avenue; thence generally northwesterly along said tributary and its northwesterly production to the southerly boundary of the Mount Pleasant Cemetery; thence generally easterly along said boundary to Mount Pleasant Road; thence northerly along said road to Broadway Avenue; thence westerly along said avenue to Yonge Street; thence southerly along said street to Eglinton Avenue West; thence westerly along said avenue to the point of commencement.
To find out whether your building is in the Toronto-St Paul's riding check the official riding map.