1) A sub-panel might be the solution for any older type panelboards (ie; fuses, older style Commander Breaker Panels) which might not at this time, be able to support the new AFCI's.
2) In Ontario, AFCI breakers will not be required retroactively, even if the service is upgraded. They would however be required for an addition containing a bedroom.
Arc Fault Circuit Interrupters will only be required for new construction, and additions or renovations when a new circuit is provided for a bedroom. AFCI's will not be required when existing receptacles are simply replaced.
© Electrical Safety Authority – 2002