Price Underground Garage Electrical Service Separately or With the Build?

The 60-foot distance makes trench ownership worth spelling out, not just the electrical price. I’d ask every bidder to show who is responsible for the trench route and conduit layout, and to provide a simple site sketch.

That route can conflict with:

- The garage footing or slab edge
- Drainage, downspouts, and any required grading
- Existing or planned water, gas, or communications lines
- Future access for repairs or another utility

I’d also have the bid identify who verifies the conduit location before excavation and who pays if the route has to move. A separate electrical quote can still work, but only if the garage contractor, excavator, and electrician agree on one layout before work starts. Otherwise, the lowest electrical number may leave the owner coordinating redesigns and surface restoration.

Each bid should state whether the electrical work is a fixed price or an allowance, and include unit rates for conditions not known until excavation, such as rock, groundwater, unsuitable soil, or extra trench depth.

It also helps to specify when those rates can be applied and who documents the condition before proceeding. That keeps a “low” bid from shifting later through vague change orders while still giving the contractor a fair way to handle genuinely unexpected ground conditions.

Unit rates for rock or groundwater only help if the owner controls when they’re used. I’d add a written change-order process to each bid:

- Define a stop-work threshold, such as unexpected conditions adding more than a stated dollar amount or changing the trench route.
- Require photos, measurements, and the contractor’s proposed remedy before extra work begins.
- State who can approve the change and require written authorization, not a verbal field decision.
- Include whether standby time or remobilization can be charged while approval is pending.

Could the contract also distinguish emergency safety work from optional cost increases? That lets the crew secure an unsafe excavation immediately, while preventing unapproved trench upgrades or surface-restoration costs from quietly becoming part of the final bill.

I’d narrowly define the emergency exception. Securing an unsafe excavation, such as shoring it, fencing it off, or pumping enough water to prevent an immediate hazard, should be allowed without waiting for approval. But that shouldn’t authorize a permanent route change, upgraded conduit, extra depth, or surface restoration.

The contractor should document the condition with photos and measurements, then stop before the permanent work continues. Any added cost, standby time, or remobilization should follow the normal written change-order process unless delaying it creates an immediate safety risk. Otherwise, “emergency safety work” can become a broad excuse for making design decisions in the field.

The narrow emergency exception matters, but the bid should also cover what happens between installation and turnover:

- Who protects open conduit and the feeder from construction damage, moisture, and debris before the garage is enclosed?
- Who replaces or repairs anything damaged by the builder or other trades?
- Who labels the detached-building subpanel and identifies the feeder disconnect and circuits?
- Who performs and documents the final electrical testing and inspection before turnover, including voltage and grounding/bonding checks by the qualified electrician?

I’d keep temporary protection and final testing in the electrical scope, while assigning the garage contractor responsibility for protecting the work during its construction activities. That avoids treating a damaged or untested installation as complete just because the trench and conduit were initially installed.

Cloudathlete’s turnover point raises one more item I’d want tied to final payment: as-built and permit-closure documentation. Would it be reasonable to require the electrician to provide:

- The installed feeder route and any relevant depth or location measurements
- Conductor sizes and conduit specification
- Grounding electrode details at the detached garage
- A final subpanel schedule and feeder-disconnect identification
- Inspection approval or other permit-closure documentation required locally

That information can matter later if the route is disturbed during landscaping, the garage is expanded, or an EV charger is added. I’d make the contract clear about which documents are actually required by the local authority, rather than assuming a generic drawing package is part of every electrical bid.