Where this service usually fits
- Converting existing space into a separate dwelling
- Detached ADUs and garage apartments
- In-law apartments within the main house
- Deciding between a subpanel and a separate service
- Meeting the requirements for a separate dwelling unit
What moves the price
How the numbers add up: how electrical pricing works
| Cost driver | Why it changes the number | Ask the electrician |
|---|---|---|
| Separate service or subpanel | This is the decision that drives everything else: metering, capacity, utility involvement and cost. | Is the unit separately metered or fed from the existing service? |
| Attached, above a garage, or detached | A detached unit needs its own disconnect, grounding electrode system and a feeder, usually buried. | Which configuration is this? |
| Combined load of both dwellings | A second kitchen, heating and water heating is a substantial addition, and existing services frequently cannot carry it unchanged. | What did the combined load calculation show? |
| Distance from the existing service | For a detached unit, distance drives conductor size, trenching and reinstatement. | What run length is assumed? |
| Heating choice | An all-electric ADU with a heat pump and electric water heating is a very different load from one on shared existing heat. | How will the unit be heated? |
| Utility requirements | Requirements for a second meter differ between the three utilities serving this region. | Which utility serves the address and what do they require? |
Information that changes the scope
- Whether the unit will be separately metered or not
- The total calculated load of both dwellings together
- Whether the ADU is attached, above a garage, or detached
- Distance and route from the existing service
- Municipal and zoning requirements already established
What an ADU electrical quote usually includes
- Feeder or service to the accessory unit
- Panel or subpanel for the unit
- Complete branch circuit wiring for the dwelling
- Grounding and, for detached units, a grounding electrode system
- Disconnecting means as required
What is usually NOT included
- Utility application fees and any separate meter charges
- Trenching and reinstatement unless quoted
- Structural and finish work on the unit
- Upgrades to the main dwelling's service that the ADU triggers
- Appliances and fixtures unless an allowance is stated
Permits, inspection and code
Whether it may be separately metered is partly a utility question and partly a municipal one, and they are answered separately.
Timing and scheduling in Vermont
Settle the metering decision first, because everything downstream depends on it. If a separate service is wanted, the utility application has a lead time that should start before construction rather than during it. This is the commonest cause of an ADU being finished but not energised.
What a clear estimate should address
Establish the metering decision before anything else, because it determines whether this is a subpanel project or a second service. Separate the ADU wiring from any upgrade the main dwelling needs to support it.