Replacing knob-and-tube (K&T) wiring in San Francisco is one of the most valuable safety upgrades you can make in an older home—and it’s also the kind of project the City expects to be permitted and inspected. The reason is simple: rewiring changes the hidden “infrastructure” your home relies on every day. If it’s done wrong (even with good intentions), it can create fire and shock hazards that may not show up until months later.
This guide explains—plainly and thoroughly—how SFDBI (San Francisco Department of Building Inspection) electrical permits work, what “SFDBI basics” actually means for a homeowner, how to avoid common permit mistakes, and what to expect from inspections and timelines in 2026. It’s written for real-world San Francisco homes: Victorians, Edwardians, stucco houses, split-levels, condos, and small multi-unit buildings where access, walls, and service equipment can be complicated.
AI Overview-style quick answer (for homeowners):
In San Francisco, a knob-and-tube replacement almost always requires an electrical permit because it involves installing new wiring and altering the electrical system. SF.gov directs applicants to the San Francisco Electrical Code and its exemptions (Section 89.121), but K&T replacement is typically not exempt. Most homeowners hire a licensed electrical contractor registered with the City to pull the permit online; homeowner electrical permits exist but are limited and come with strict conditions (and are not available to LLC-owned properties).
1) The San Francisco permitting landscape in one minute
In San Francisco, “permits” aren’t a single thing. They’re a system.
- SFDBI is the department that issues building-related permits and performs inspections.
- Electrical Inspection Division (EID) is the DBI division that focuses on electrical permits and inspections, fee schedules, and the electrical permitting portal.
- Electrical permits are connected to inspections. Permits without inspections don’t really “complete” the job in the City’s eyes.
For a homeowner planning a rewire, the big picture is:
- Define scope (what’s being rewired, what’s being added/replaced).
- Pull the correct permit (usually by a contractor, sometimes by a homeowner).
- Complete work in phases (rough → approval for cover → final).
- Pass inspections (inspection logs become part of the permit record).
- Close out permit with final approval/sign-off.
2) Do you need a permit to replace knob-and-tube wiring in San Francisco?
Almost always, yes.
SF.gov states you need an electrical permit before installing new wiring or doing alterations, extensions, or additions to existing electrical installations. It also points to the exemptions list in San Francisco Electrical Code Section 89.121.
A knob-and-tube replacement typically includes:
- installing new cable (modern wiring methods),
- changing circuit routing and splices,
- adding or restoring equipment grounding,
- updating devices and often adding protection like AFCI/GFCI,
- and sometimes service/panel work.
That’s the definition of “installing new wiring” and “alterations,” so it’s usually permit-required.
But what about “minor electrical work”—is any of it exempt?
Yes. The code contains a “Work Exempt from Permits” section (89.121) with specific limited cases. This is where homeowners get tripped up: the exemptions are narrow and typically apply to simple replacements where you are not altering wiring in a meaningful way.
A full K&T replacement does not behave like a “swap a switch” job. It’s a system upgrade.
3) Who can pull the electrical permit in SF: contractor vs homeowner
This is one of the most important choices you’ll make because it impacts how smoothly inspections and sign-off go.
Option A: A licensed contractor pulls the electrical permit (most common)
SF.gov is clear: to apply for an electrical permit online, you must be a licensed contractor registered with the City of San Francisco.
San Francisco also has “instant online permits” and contractor portals intended for registered contractors to obtain electrical permits quickly.
Why this route is usually best for K&T replacement
- Contractors do this work under inspection rules regularly.
- They understand what inspectors look for at rough and final.
- They can schedule inspections as the permit applicant (which matters in SF’s inspection scheduling workflow).
Option B: Homeowner’s Electrical Permit (limited and strict)
San Francisco does allow homeowner electrical permits under specific conditions. The official homeowner permit application includes strong language homeowners should take seriously:
- “All electrical wiring shall remain exposed until approved for cover by the electrical inspector.”
- “PLEASE REVIEW PERMIT FOR ACCURACY. OMISSIONS AND CORRECTIONS REQUIRE A NEW PERMIT.”
And the San Francisco Electrical Code (as published by SF.gov) explains that homeowner permits may be issued when the work is performed by the homeowner—but if the work doesn’t comply, deficiencies can require correction by a state licensed electrical contractor under a separate permit.
Ownership structure matters (LLCs are a hard stop)
The San Francisco Electrical Code notes: LLC’s are not eligible for an Electrical Homeowner’s Permit.
If your property is owned by an LLC, the homeowner-permit route may not be available—plan on a contractor permit.
Practical reality check (especially for knob-and-tube)
If the job involves opening walls, fishing cable through old framing, dealing with plaster, and meeting modern protection requirements, homeowner-performed rewires often hit inspection hurdles. It’s not about talent—it’s about the volume of code details and the “inspection readiness” standard.
4) Online vs in-person permitting in San Francisco (what’s realistic in 2026)
Contractor pathway (online / instant)
SF.gov explicitly supports online electrical permits for registered contractors.
The contractor portal for electrical permitting and scheduling is publicly accessible as a DBI “Electrical Permitting and Inspection Scheduling” site.
In-person support (DBI Permit Services)
DBI Permit Services provides over-the-counter and in-house processing pathways and is also the place people go when a project becomes more complex or crosses into plan review territory.
Homeowner pathway (application + approval)
SF provides a dedicated Homeowner’s Electrical Permit Application form and expects in-person coordination with EID.
5) Permit fees: how SF calculates electrical permit and inspection costs
San Francisco electrical permits aren’t priced like a simple “flat fee.” Fees depend on scope.
SFDBI publishes an electrical permit fee schedule called:
“Electrical Permit Issuance and Inspection” (Table 1A-E)
This fee table applies to permits issued on and after September 1, 2025, and instructs applicants to itemize scope and match categories and fees accordingly.
The key concept: your permit fee is tied to scope and “count”
In residential rewiring, fees often relate to:
- the number of outlets/devices affected,
- sometimes whether a service upgrade is included,
- and how many inspections are built into the category.
The fee schedule itself is the authoritative reference your electrician should use while creating the permit application scope.
Why this matters for homeowners
A knob-and-tube replacement can sound like one job (“rewire the house”), but the permit scope might include:
- lots of receptacles and switches,
- lighting outlets,
- hardwired equipment and appliances,
- smoke/CO related electrical tie-ins (if part of the project),
- and panel/service work.
That scope affects permit categories. If the scope is undercounted, the permit may not match the work performed, which can complicate inspections or close-out.
6) “Do I need a building permit too?” — the truth for San Francisco rewires
Sometimes you only need an electrical permit. Sometimes you end up needing additional permits.
You may only need an electrical permit if:
- the rewire is mostly done by fishing cable through walls/ceilings with minimal patching,
- no significant structural work is involved,
- lighting layouts aren’t being redesigned in a way that triggers broader building review,
- and you aren’t changing use/occupancy or doing major remodeling.
You may need more than an electrical permit if:
- you are opening large areas of walls/ceilings,
- remodeling kitchens/baths at the same time,
- relocating fixtures substantially,
- altering framing or fireblocking,
- or combining the rewire with broader renovation work.
DBI Permit Services distinguishes between over-the-counter review (smaller plan review needs) and in-house review (complex projects), and it’s common for “scope creep” to push projects into the more complex bucket.
Homeowner tip: If you’re planning a “rewire + remodel,” treat it as one coordinated permit strategy—not separate projects you hope won’t collide.
7) Inspections: what SFDBI typically expects for a rewire
Permits are about two things: authorization and verification. SF verifies electrical work through inspections.
Even the homeowner permit form emphasizes the core rule: keep wiring exposed until the inspector approves cover.
The typical inspection rhythm for a rewiring project
Every project varies, but many rewires naturally fall into:
1) Rough inspection (“before cover”)
This is the inspection that often determines schedule success. The inspector wants to see:
- cable routing,
- support/stapling,
- box installation,
- grounding/bonding connections where visible,
- splices and junction boxes that will remain accessible,
- and workmanship quality before it disappears behind drywall/plaster.
2) Service energize / “green tag” (if applicable)
If your project includes service work, there may be a step that grants permission to energize. DBI inspection scheduling codes include a concept such as “Green tag – Energize service,” which shows that energizing is treated as a controlled milestone.
3) Final inspection
At final, inspectors commonly look for:
- correct devices installed (tamper-resistant receptacles, correct ratings),
- proper labels and panel directory completeness,
- required protective devices installed (AFCI/GFCI where applicable),
- covers on junction boxes, no open splices,
- and overall safe operation.
8) Scheduling electrical inspections in SF (the part homeowners feel)
SF.gov provides an inspection scheduling page that explains what’s needed and highlights a key SF rule:
- For electrical permit inspections, you need the permit application number and the contractor license number (must be the permit applicant) when scheduling as a contractor.
That line is extremely important in real life:
If a contractor pulled the permit…
They usually need to schedule inspections as the permit applicant (or at least provide the license/permit applicant details as required). Coordinate early so you’re not stuck waiting with open walls.
If you pulled a homeowner permit…
You are the permit holder, so you’ll be the one handling inspection coordination—while also managing exposed wiring and patch schedules.
9) San Francisco-specific realities that make K&T rewires unique
A generic “electrical permit” article won’t prepare you for San Francisco housing stock. Here are the details that matter.
Old walls aren’t just “walls”
San Francisco homes often include:
- lath-and-plaster,
- balloon framing in older structures,
- unpredictable stud bays,
- fireblocking that complicates cable routes,
- and previous remodel layers.
This affects how the wiring is run, where junction boxes can be placed, and how much opening is necessary—all of which influences permit scope and inspection readiness.
Many SF homes have electrical “history”
It’s common to find:
- a mix of old and newer wiring,
- abandoned K&T remnants,
- partial grounding retrofits,
- crowded panels from decades of add-ons,
- and DIY work done without permits.
A quality rewire often includes cleanup and clarification work (properly abandoning old conductors, re-labeling circuits, correcting unsafe splices) so the final system is understandable and serviceable.
10) Code concepts homeowners should understand (without turning you into an electrician)
You don’t need to memorize code, but you should understand the “why” behind what inspectors care about. This is how you avoid surprise change orders.
Grounding and bonding: the safety backbone of modern wiring
Knob-and-tube wiring typically lacks the equipment grounding conductor modern devices assume exists. During replacement, the electrician must ensure:
- proper grounding continuity to devices and metal boxes where required,
- proper bonding at service equipment,
- correct handling of metal piping bonding where applicable,
- and that grounding paths are reliable (not “creative”).
Homeowner lens: Grounding is often the biggest “invisible upgrade” you’re paying for.
Circuit design: modern loads need modern circuits
Homes today have loads older systems were never designed to support:
- microwaves, induction, espresso machines,
- window AC / heat pumps,
- bidet seats,
- home office loads,
- and EV charging readiness.
A good rewire includes a circuit plan that avoids overload and nuisance tripping—and anticipates near-future upgrades.
AFCI/GFCI: protection requirements that show up at inspection
When circuits are modified, modern requirements often come into play. That can mean:
- more protective breakers,
- GFCI protection in wet and exterior locations,
- AFCI protection in many living areas.
Even if you didn’t care about these terms yesterday, they can become inspection requirements during a rewire.
11) Emergency work: what SF allows—and what it still requires
If there’s a real hazard—smoke, arcing, melted insulation, water intrusion into energized wiring—work may need to start immediately. The San Francisco Electrical Code includes an emergency-work rule:
- Emergency electrical work can begin for protection of persons/property, but a permit must be obtained within one business day of commencing the emergency work.
Homeowner takeaway: “Emergency” doesn’t mean “skip permits.” It means “make safe now, document and permit immediately.”
12) Condo and multi-unit complications: permits may be per unit/structure
If you’re not in a stand-alone single-family home, the permit strategy can change.
San Francisco’s electrical fee schedule notes that separate permits are required for each structure, condominium unit, dwelling unit (with certain exceptions), and common areas.
What that means in practice:
- rewiring a condo unit might require a unit-specific permit,
- work involving common electrical rooms or meters may require additional coordination,
- HOA approval and building access often become schedule-critical.
13) A step-by-step “clean permit” plan for a San Francisco K&T rewire
Below is a homeowner-friendly process that usually produces fewer surprises.
Step 1: Scope definition (the part that controls everything)
Ask your electrician to write the scope in plain English, including:
- which areas will be rewired,
- whether any K&T remains (and how it will be handled),
- how many new circuits are being added,
- whether panel/service work is included,
- what devices/fixtures are included in the count,
- and what patching approach is assumed.
Why: Permit fees and inspections tie back to scope and category.
Step 2: Permit strategy (contractor permit vs homeowner permit)
- If hiring a contractor, confirm they are registered to pull permits online in SF (SF.gov explicitly ties online permitting to registered licensed contractors).
- If considering homeowner permit, confirm eligibility and accept that the wiring must remain exposed until approved, and corrections can require a licensed contractor under a separate permit.
Step 3: Open walls strategically (not randomly)
In older SF homes, wall opening strategy affects timeline:
- open what you must for safe routing,
- keep everything accessible for rough,
- avoid patching until rough approval.
This aligns perfectly with the homeowner permit form’s “exposed until approved for cover” rule.
Step 4: Rough inspection readiness checklist (homeowner version)
Before rough inspection, you want:
- no hidden splices,
- boxes solidly mounted,
- cable protected from damage,
- grounding conductors landed as required,
- labeling started (at least circuit intentions),
- clear access to panel and work areas.
Step 5: Final inspection readiness checklist (homeowner version)
Before final:
- devices installed and properly rated,
- covers on everything,
- panel directory clearly and accurately updated,
- protective devices installed,
- no loose ends or “we’ll finish later.”
14) Common permit problems in San Francisco—and how to avoid them
Problem 1: “We didn’t list that on the permit”
This is the #1 inspection friction point: the work in the walls doesn’t match what the permit implies.
Fix: Make sure the permit scope reflects the real job. The fee schedule explicitly expects the scope to be itemized to calculate fees correctly.
Problem 2: Covering wiring before approval
This can cause re-open requirements.
Fix: Follow the explicit instruction: wiring stays exposed until the inspector approves cover.
Problem 3: Ownership/eligibility misunderstandings (homeowner permit)
A homeowner permit is not a flexible “I’m the owner, so I can do anything” path.
Fix: Confirm ownership structure and eligibility. LLC ownership blocks homeowner electrical permits per the Electrical Code.
Problem 4: Scheduling expectations
If the permit applicant must be the contractor license holder for scheduling, last-minute scheduling attempts can go sideways.
Fix: Align with SF’s scheduling requirements.
15) Timeline expectations in 2026: what a realistic SF rewire schedule looks like
Every house is different, but the permit-and-inspection shape of the timeline is fairly consistent.
Phase A: Planning + permit issuance
- Contractor online permits can be fast when scope is clear and contractor registration is in place.
- Homeowner permits can take longer because of approval steps and document verification.
Phase B: Rough work + rough inspection
This phase often takes the longest, because it’s the portion where old-house obstacles appear:
- unexpected fireblocking,
- crowded wall cavities,
- prior remodel surprises,
- inaccessible runs.
Phase C: Patch/close + final
Once rough is approved, patching and final trim-out proceeds, then final inspection closes the permit.
16) Why permits are worth it (even if you hate paperwork)
A clean, inspected rewire gives you:
- A safer electrical system that’s verifiable.
- A permit record you can reference later (and a contractor can stand behind).
- Fewer insurance and resale headaches related to unpermitted electrical work.
- More confidence when adding future loads (HVAC upgrades, EV charging, kitchen remodels).
In San Francisco, permits are part of how you turn “work performed” into “work accepted.”
17) Homeowner-friendly mini glossary (SF terms you’ll hear)
- SFDBI: San Francisco Department of Building Inspection.
- EID: Electrical Inspection Division, within DBI.
- Table 1A-E: SF’s electrical permit issuance and inspection fee schedule.
- Permit applicant: The party responsible for the permit; often the contractor who must be the applicant for scheduling inspections (as described on SF.gov).
- Rough inspection: The “before cover” inspection stage.
- Final inspection: The completion inspection and sign-off stage.
Emergency work: Work allowed immediately for safety, but still requires a permit within one business day.