It will be cheaper to do the whole house at once. Generally, here’s what most likely needs to happen:
2. Heavy-up (replacing feeder cable from meter to panel)
3. Install new breaker panel
4. Run new copper wire from panel to switches/receptacles/etc, opening up large areas of the walls as necessary to route the wiring (this is especially challening in petworth houses that have the wiring buried in the plaster on the brick exterior walls).
5. Replace and rewire switches, receptacles, and possibly the electrical boxes
6. Patch drywall and re-paint
For a typical petworth rowhouse you’re probably looking at 10-15k for the electrical work and another 5k or so in drywall and paint. That’s a very rough estimate based on a full gut renovation we did in 2010.
You don’t just need an electrician for this – you need drywall guys & painters too. And be prepared to encounter all sorts of unexpected problems as they open up the walls.