1900 Nelson Street appeared only once in the Vancouver directories. In 1906 it was the address for Donald Greenfield Macdonell.
It seems to have been either a temporary address or, perhaps, a mistaken entry for 1906 Nelson Street.

Vancouver directory listings for 1906 Nelson Street:
1907 to 1916 | Donald Greenfield Macdonell |
1917 to 1931 | James Murray Lay |