Is 200 amp service required for every older home?
A home’s age alone does not establish that it must reach 200 amps. Washington allows lawfully installed existing installations to continue under stated conditions; alterations must meet applicable current requirements.
- An old rating alone does not explain whether a proposed EV charger, heat pump or remodel fits.
- Start with a documented assessment.
Which equipment might need to change?
Ask about the service disconnect, meter socket, service entrance, grounding and bonding, panel and existing feeders. The utility determines its connection and metering requirements.
- Overhead service and underground service have different site questions, including route, access and possible trench or right-of-way work.
- Do not compare a panel-only quote with a complete service upgrade as if they are interchangeable.
What affects the installation day?
The contractor, inspection authority and utility have separate responsibilities. Ask who schedules the outage and inspection, what must pass before reconnection and what the contingency is if approval or utility work is delayed.
- A standard installation window cannot promise the whole project’s calendar duration.
What is useful to send with an estimate request?
Provide the project address, utility shown on the bill, safe photos of the closed panel and exterior labels, and a list of planned equipment. Do not remove covers to find a rating.
- If the service rating is uncertain, say so rather than using the panel label as a confirmed service measurement.
How should a staged upgrade be documented?
If the service work is completed before the appliance projects, ask what future loads were included in the assessment and which circuits still need installation. Identify any equipment location or route that should be planned now to avoid incompatible later work.
- Keep assumptions and exclusions in the written proposal.
- A service upgrade can prepare part of a project while the EV charger, heat pump or addition still requires its own equipment review, permit and installation.
Sources and scope
Primary-source research reviewed October 17, 2026 for 100 to 200 amp service: what changes?. Code, utility standards and administrative guidance have different roles. Confirm current requirements for the project address.