To compare knob and tube rewiring quotes, line them up by scope before price: how many circuits each replaces, what new circuits it adds, what it excludes, which costs are allowances, and who handles the permit and inspection. Only when those match does the total tell you which offer is better value.
Philly Knob & Tube provides knob and tube rewiring across Philadelphia through licensed electrical contractors, and this guide is written for the homeowner holding more than one proposal, including one of ours. A printable version of the comparison worksheet is on the resources page if you would rather fill it in by hand.
Compare like-for-like circuit scope
The most common reason two quotes differ is that they describe different amounts of work. Start by writing each quote’s scope as numbers:
- Circuits replaced. How many existing knob and tube circuits does each quote replace? If one says “rewire the house” without a count, ask for one.
- New circuits added. Modern use often calls for dedicated circuits for a kitchen, bath, laundry or window air conditioner. One quote may include them and another may treat them as extras. The appliance loads guide explains why they come up.
- Devices. How many receptacles, switches and fixture connections are replaced or added? Are new boxes included where old ones cannot accept modern devices?
- Protection. Are AFCI or GFCI devices included where the 2020 NEC requires them for the new work?
- Old wiring. Will replaced conductors be disconnected at both ends and documented, or physically removed where accessible? The removal page explains the difference.
If neither quote is based on a circuit map, both are estimates of the same unknown. An assessment first, as described on the inspection service page, gives every bidder the same starting point.
What is actually excluded
Exclusions are where cheap quotes become expensive jobs. Read each proposal’s exclusion list, and if it has none, ask. The items that most often sit outside an electrical quote are:
| Item | Why it matters |
|---|---|
| Finish plastering and painting | Rough patching closes openings; finish work makes them disappear. They are different trades and prices. |
| Panel replacement or added capacity | New circuits may need panel space the current panel lacks. |
| Service upgrade and utility coordination | A larger service involves PECO and is a separate scope. |
| Removal of abandoned wiring | Disconnecting and documenting is one price; pulling out old runs is another. |
| Insulation removal and replacement | Attic insulation over old runs may need to be moved and replaced. |
| Hazardous material testing or abatement | Openings in older plaster or near old pipe wrap may call for testing first. |
| Moving furniture and protecting finishes | Occupied-home protection takes time and is priced differently. |
An exclusion is not a flaw. A quote that excludes painting and says so is easier to compare than one that is silent. The problem is the quote whose silence you discover after the walls are open. The plaster wall rewiring page covers what restoration involves, and the asbestos guide covers when testing belongs in the plan.
Allowances, unknowns and change orders
No one can see inside closed walls, so every honest rewiring quote carries some uncertainty. Contractors handle it in different ways:
- Allowances. A set amount for an uncertain item, such as additional access openings, with the actual cost trued up later.
- Contingency language. A clause saying concealed conditions will be priced as found.
- Unit prices. A stated price per additional opening, device or circuit, so changes are predictable.
Each approach is legitimate. What you want is to know which one each quote uses and how a change gets approved. A quote with low allowances will look cheaper than one with realistic allowances, but the final invoices may land in the same place. Ask each bidder: if you find more knob and tube than expected, how will it be priced, and will I approve it before you proceed?
Permit and inspection responsibilities
In Philadelphia, rewiring needs an L&I electrical permit, the work must be done by a licensed electrical contractor, and a licensed third-party inspection agency performs the inspections. A complete quote says:
- who files the permit in eCLIPSE, normally the electrical contractor as the owner’s agent
- whether the permit fee is included and roughly what it is
- which inspection agency will be used and whether its fee is included
- whether a Building Permit is needed for the scope, and who handles it
- how rough-in inspection is scheduled around patching
If two quotes differ on these points, the cheaper one may simply be leaving the permit and inspection costs to you. The Philadelphia permit guide shows how the fee is calculated, so you can estimate it yourself and see which quote has absorbed it.
Why labor dominates the number
Most of the money in a knob and tube rewire pays for time: tracing circuits, fishing cable through finished walls, setting boxes in plaster, and working around a household that still lives there. Materials matter, but the hours are what vary most from one house to the next. That is why two quotes with similar material lists can still be far apart, and why the hours each contractor expects to spend are worth asking about.
Philadelphia labor also costs more than the national average. Bureau of Labor Statistics wage data, published through O*NET, puts the median electrician wage in the Philadelphia metro area at $35.86 an hour, against a national median of $30.38, about 18 percent higher. A wage is not a billing rate. What a contractor charges per hour also has to cover licensing, insurance, vehicles, tools, permits, unbillable travel and overhead. The point is not to calculate a fair hourly rate; it is that a quote far below its competitors usually assumes fewer hours, and fewer hours usually means less scope, fewer openings planned or less finish work.
So when one quote is much lower, ask how long the job is expected to take and how many people will be on site. If one contractor plans four days and another plans eight for the same house, the difference is in how each expects the walls and access to behave, and that is the conversation worth having.
Questions to send every bidder
Sending the same written questions to everyone makes answers comparable. A short list covers most of the gaps:
- How many existing knob and tube circuits will be replaced, and how did you count them?
- Which rooms will need wall or ceiling openings, and roughly how many?
- What level of patching is included, and does it include painting?
- Will the panel need changes for the new circuits, and is that priced here?
- Who files the permit, which inspection agency will be used, and are their fees included?
- How are hidden conditions priced, and how will I approve changes?
- What will happen to the old wiring: disconnected and documented, or removed?
- What documents will I receive at the end?
A contractor who answers these clearly in writing has given you more than a price. One who will not answer them has also told you something.
Putting two quotes on the same footing
Once you have the facts above, a simple table makes the comparison concrete. Give each quote a column:
| Line | Quote A | Quote B |
|---|---|---|
| Active knob and tube circuits replaced | ||
| New dedicated circuits | ||
| Devices replaced or added | ||
| Panel or service work | ||
| Patching level (rough or finish-ready) | ||
| Painting | ||
| Permit and inspection fees | ||
| Allowances and how overruns are priced | ||
| Disconnection or removal of old runs | ||
| Written circuit list at completion | ||
| Total as quoted |
Then adjust. If Quote A excludes painting and Quote B includes it, estimate what painting would add to A. If Quote B carries a small allowance for openings and A carries a realistic one, note the risk. The adjusted totals are the numbers worth comparing. The Philadelphia cost guide gives a planning range for a substantial whole-home job, $9,000 to $25,000, which is useful as a sanity check but not a substitute for line-by-line comparison.
How to choose a comprehensible proposal
After the numbers, read for clarity. A proposal you can understand is one where you can say, in your own words, which circuits will be replaced, what your walls will look like when the electrician leaves, what is not included, and what happens if something unexpected turns up. If you cannot, ask until you can.
Schedule belongs in the comparison too. A quote that starts next week and one that starts in two months are not equal if an insurer or a closing has set a deadline, and a contractor who plans to finish in fewer days may be planning fewer openings or a smaller crew. Ask each bidder for an expected duration and what it depends on. The replacement timeline guide explains which phases set the length of a job, so you can tell whether a schedule is realistic.
Watch for a few patterns that should prompt questions: a promise that no walls will be opened, a claim that a new panel will take care of the knob and tube, a guarantee that your insurer will accept the result, or a price given over the phone without anyone seeing the house. None of these can be known in advance. The hiring guide covers how to check the contractor behind the proposal, and the guide to living at home during rewiring helps you weigh schedules.
If you would like a proposal to set beside the ones you have, the whole-home rewiring service explains how scope is set, and the contact page starts the conversation.
