Yes, existing electrical installations can often be modified or extended; however, any modifications must comply with current codes and regulations as mentioned earlier. Before proceeding with modifications, its crucial to assess the capacity of the existing system to ensure it can safely handle additional load. Upgrades may require replacing older components like wiring, services panels, or outlets to accommodate increased demand or meet code requirements for new types of equipment being added to a system. Always consult a qualified electrician before attempting any modifications to an electrical installation.