In Burlingame, a Bay Area suburb near San Francisco, a seller cannot transfer title on a home built more than 25 years before the sale until a licensed plumber threads a camera through the sewer lateral and the city signs off on the results. South San Francisco has run a nearly identical rule since June 2022, backed by a deposit that can run into five figures if a seller tries to push the inspection past closing. In North Park, none of that applies. Nobody at the city or the county requires you to look at the pipe running from your foundation to the sewer main before you hand someone the keys.
That gap matters more in North Park than almost anywhere else in San Diego, because North Park is old. The Dryden Historic District, laid out along 28th Street and Pershing Avenue starting in 1915 by master builder David Owen Dryden, and the Burlingame Historic District nearby are full of Craftsman bungalows and Spanish Revival homes built mostly between 1905 and 1940. That's eighty-five to well over a hundred years of clay or cast iron pipe sitting in ground that also grows the mature trees these blocks are known for. Nobody is checking that pipe unless someone decides to.
What Other Cities Require, and What San Diego Doesn't
| Where | Sewer lateral certification required before sale? |
|---|---|
| San Diego | No citywide or countywide mandate |
| South San Francisco | Yes, required under a point-of-sale ordinance in effect since June 2022 |
| Burlingame | Yes, testing required whenever a structure was built more than 25 years before the transfer date |
San Diego County is direct about where the responsibility sits, even without a certification requirement attached to it. The county's own guidance states plainly that the owner is "responsible for maintenance and repair of the lateral from the building all the way to the point of connection with the public sewer main." Responsibility for the pipe never disappears. What disappears is any outside party forcing a look at it before a sale closes.
What the Missing Rule Actually Costs
A camera scope of a single sewer line typically runs a few hundred dollars. If that scope finds a break, an offset, or a root mass that's narrowed the pipe to a trickle, the repair conversation changes entirely. Length, depth, and what's sitting on top of the line, whether that's a driveway, a mature olive tree, or a hundred-year-old sidewalk, all drive the cost, and a full replacement can land well into five figures.
Because no one is required to order the scope, the only person who does is whoever thinks to ask. In a neighborhood where clay pipe from before 1950 is common and every joint is a potential entry point for roots, that turns a routine maintenance item into a negotiation variable. A general home inspector checks the roof, the panel, the water heater, and the foundation. Sewer lines run underground and out of sight, which is exactly why most general inspections don't include them as a matter of course. A clean inspection report and a failing sewer line are not mutually exclusive. They're a common pairing in this housing stock.
For a seller, that means ordering the scope before listing, not waiting for a buyer's inspector to find it during a short contingency window. For a buyer, it means not assuming the absence of a requirement means the absence of a problem.
The Wiring Problem Shows Up in the Insurance Quote, Not the Inspection Report
Many of North Park's pre-1950 homes were wired with knob-and-tube, a system common in San Diego homes built from the 1920s into the early 1950s that runs individual wires through ceramic knobs and tubes without a ground. A licensed inspector will flag it where it's visible, in an open attic or an exposed crawl space. What an inspector won't flag, because it isn't their job, is what happens next in the insurance market.
California homeowners insurance carriers have grown far less willing to write or renew policies on homes with active knob-and-tube wiring still in the walls. That's not a code violation. It's an underwriting decision, and it tends to surface during loan processing rather than during the inspection period, which means it can appear with far less runway to fix it. A full rewire on a typical Craftsman-sized home runs somewhere between $8,000 and $22,000 depending on the home's size and how hard the walls are to access.
The practical effect is that a home can pass its inspection cleanly and still stall in escrow because a buyer's lender needs proof of an insurance binder that the buyer can't get until the wiring is addressed. Sellers who know their home still carries original wiring are better off getting ahead of that conversation before an accepted offer depends on it.
Mills Act Complicates the Math Buyers Think They're Getting
Plenty of the historic homes in the Dryden and Burlingame districts qualify for a Mills Act contract, which reduces the property tax basis on a qualifying historic home by a meaningful margin. It's a real selling point, and buyers are right to value it. Where the friction shows up is in what a Mills Act contract actually is: an agreement that runs with the property, not a one-time discount that resets or disappears at sale.
A new owner inherits both the tax benefit and the obligations that come with it, including restrictions on exterior alterations that require review before work begins. A buyer who assumes the reduced tax bill is simply how the property is now, without understanding that maintaining it depends on keeping the contract in good standing, can be surprised later by what a remodel actually requires. Sellers marketing a Mills Act home should have the contract terms and current documentation ready to hand over, rather than let a buyer discover the fine print after closing.
Where This Lands in Today's Numbers
As of June 2026, MLS figures for the 92104 zip code showed detached homes selling at a median of roughly $1,150,000, with well-priced listings going under contract in about 29 days and only around 2.6 months of supply on the ground for detached inventory. A balanced market runs closer to six months, so North Park is still moving fast for sellers.
That speed is exactly why these three issues matter more, not less, right now. A market that moves in under 30 days doesn't leave much room for a slow discovery process. An accepted offer typically comes with a 7 to 10 day inspection window, and that's the window where a sewer scope, an insurance quote, or a Mills Act question either gets handled calmly or turns into a scramble that threatens the closing date. In a slower market, there's time to absorb a surprise. In this one, whoever did the work before listing is the one who keeps the deal on schedule.
Before you list a North Park home built before 1940, it's worth working through three things in order:
- Order a sewer lateral camera scope and have the report in hand, whether or not a buyer asks for one.
- If the home still has original wiring, get a same-day homeowners insurance quote so you know whether a buyer's lender is likely to run into a binding problem.
- If the home carries a Mills Act contract, pull the paperwork and confirm what maintenance and alteration terms transfer with the sale.
None of these are required by any ordinance. That's the point. In San Diego, getting ahead of them is a choice, and it's the choice that decides whether a fast market works in your favor or against it.
Frequently Asked Questions
Does San Diego require a sewer lateral certificate before I can sell my home? No. Unlike cities such as Burlingame and South San Francisco, San Diego has no citywide or countywide mandate requiring a camera inspection or certification of the sewer lateral before a sale closes. The property owner remains responsible for the pipe's condition regardless.
Will a home inspector catch knob-and-tube wiring during a standard inspection? An inspector will typically note visible knob-and-tube wiring where it's exposed, such as in an attic. What a standard inspection won't tell you is whether a homeowners insurance carrier will write a policy on the home, which is a separate underwriting decision that can surface later in the loan process.
Does a Mills Act contract automatically transfer to a new owner? Yes. The contract runs with the property, not the individual owner, which means the tax benefit and the maintenance obligations both pass to whoever buys the home.
If you're weighing when to list a North Park Craftsman or Spanish Revival home, or you want a straight read on what your specific property's sewer, wiring, or historic-tax situation looks like before you go to market, Beyond The Keys Realty can walk through it with you street by street. Start Your Move — Schedule a Free Consultation.
