I am in the process of doing a knob and tube removal, There is one overhead light off a porch that rather than have me rewire, the owners would like to install a solar battery operated floodlight. Is it code legal to have a battery light be the only source of light on the exterior entrance of a house??
It may not be. If you are governed by the International Residential Code, the following may apply.
E3903.3 Additional locations. At least one wall-switch-controlled
lighting outlet shall be installed in hallways, stairways,
attached garages, and detached garages with electric power. At
least one wall-switch-controlled lighting outlet shall be
installed to provide illumination on the exterior side of each
outdoor egress door having grade level access, including outdoor
egress doors for attached garages and detached garages
with electric power. A vehicle door in a garage shall not be considered
as an outdoor egress door. Where one or more lighting
outlets are installed for interior stairways, there shall be a wall
switch at each floor level and landing level that includes an
entryway to control the lighting outlets where the stairway
between floor levels has six or more risers.
There may be an out:
Exception: In hallways, stairways, and at outdoor egress
doors, remote, central, or automatic control of lighting shall
be permitted.
So, if the light comes on automatically at night you may be OK. Assuming the light stays on until dawn.