Electrical comparisons

Subpanel vs. service upgrade. If you are out of breaker slots but your service amperage is adequate, a subpanel at $400–$1,750 solves it, per This Old House. If the service itself cannot carry the load, a subpanel just moves the problem. The deciding document is a load calculation.

Repair vs. replace the panel. A single failed breaker is a $50–$100 part swap, per Inch Calculator. Full replacement makes sense when the panel is at capacity, is a model with documented failures, shows heat or corrosion damage, or parts are unobtainable. 'It's old' by itself is not a reason.

Remediate vs. rewire. With aluminum branch wiring, connection-level remediation at roughly $50–$75 per outlet is a very different number from a $12,000–$36,600 whole-house rewire, per HomeGuide. With knob-and-tube, rewiring is usually the realistic path, partly because many insurers treat it as a coverage issue.

100A vs. 200A. If you are already upgrading, the marginal cost of going to 200A is often modest relative to doing the job twice. This Old House puts 100-amp panel-plus-install at $800–$1,500 and 200-amp at $1,300–$3,000. Decide against your future loads — EV, heat pump, induction range, ADU — not just today's.

How to choose

Make the load calculation the tiebreaker

Every comparison here resolves to the same document. Ask for it. A contractor unwilling to produce one is guessing.

Price the do-it-twice scenario

Ask each bidder what it would cost to come back and upsize later. That number usually makes the right choice obvious.

Get repair and replace priced by the same contractor

If a contractor will only quote the replacement, ask them to also quote the repair and explain in writing why it is insufficient.

Factor insurance into the comparison

Some conditions — knob-and-tube in particular — affect insurability. Call your carrier before you choose, because it can flip the math.

Do not compare on price alone

Confirm all bids include the same scope: permit, inspection, service-entrance work, and wall repair. Otherwise you are comparing different jobs.