Windows & Doors Permits, Codes & Inspections in CA: What You Need to Know

Windows & Doors Permits, Codes & Inspections in CA: What You Need to Know

Most San Francisco homeowners assume a window replacement is a window replacement. Then they discover, sometimes mid-project and sometimes at resale, that California’s building code draws a sharp line between swapping like for like and changing what a window is. The line is rarely visible from the curb, but it determines whether your job gets a permit, whether Title 24 energy compliance comes into play, and whether a city inspector will ever set foot in your home. In San Francisco, that line is drawn even more precisely than in most of the state, because the Department of Building Inspection and the Planning Department both have a say depending on your neighborhood and your building’s age. This guide walks through exactly where that line falls, what codes apply in 2026, what inspections look like, and how to keep a simple window or door project from becoming a paperwork tangle. For The Complete Guide to Windows & Doors in San Francisco and more guides & resources, see our blog.

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Quick Answer

In California, a like-for-like window or door replacement, where you swap an existing unit for a new one of the same size, same operating type, and same rough opening, often requires no building permit and no Title 24 energy compliance review. But if you change the opening size, the operating style, the frame material, or the glass area, you will almost certainly need a permit in San Francisco, and a Title 24 energy document will be part of it. The distinction matters before you sign a contract, not after, because the wrong assumption can stall a job for weeks and add hundreds in unexpected fees.

Table of Contents

• What ‘Like-for-Like’ Replacement Actually Means in the California Building Code
• The Four Variables That Push a Project Out of Permit-Exempt Territory
• Title 24 Energy Requirements for San Francisco in 2026: U-Factor and SHGC Explained
• San Francisco DBI’s Permit Process for Windows and Doors: Forms, Timelines, and What to Expect
• Historic District Overlays in San Francisco: How Planning Review Changes the Permit Path
• Closing the Permit: Why a Signed-Off Permit Card Is Non-Negotiable
• Common Mistakes to Avoid
• When to Call a Professional
• Frequently Asked Questions

Before we get into the details, it helps to understand where this guide is written from. We are Lightwell Windows San Francisco, part of the Cedarwell network since 2010, and we have walked hundreds of San Francisco homeowners through this exact process: which forms to file, which approvals to expect, and which questions to ask before the first window comes out. Keith Yamada leads our work here, and the guidance below reflects what we see at the DBI counter, in plan check comments, and on job sites across the city. Our Lightwell Windows San Francisco home page has more on who we are and how we work, but the article that follows is written to be useful whether you ever call us or not.

What ‘Like-for-Like’ Replacement Actually Means in the California Building Code

Section 105.2 of the California Building Code, which adopts and amends the model code, lists work exempt from permit requirements. The relevant line for windows and doors is narrow: minor repair work and the replacement of glazing in existing openings. What that means in practice, and what DBI has accepted for years, is that you can remove an old window and install a new one of the same dimensions in the same rough opening without pulling a permit, provided the unit is not structurally altered and the installation does not change fire or life safety conditions.

The phrase “same dimensions” does the heavy lifting. Same width, same height, same depth of frame where the wall is concerned. If the existing opening is 36 inches wide by 48 inches tall and the new window fits that opening without cutting new framing, you are probably in permit-exempt territory. The caution is that San Francisco inspectors and plan reviewers look at the word like more strictly than many contractors assume. Changing a fixed picture window to an operable casement is not like for like. Changing a wood frame to vinyl or aluminum is not like for like, even if the rough opening is identical. We have seen this interpretation hold consistently at DBI, and it is one of the most common surprises for homeowners who thought their project was straightforward. See Windows & Doors Warning Signs: A San Francisco Homeowner’s Reference Guide for other red flags.

Doors follow the same logic. Swapping a worn entry door for a new one in the same rough opening, with the same swing and the same glass area, typically needs no permit. But San Francisco’s older housing stock means few doors are truly standard. A pre-1940s home in the Sunset or the Richmond may have a door that was never a standard size, and matching it often means a custom order, not a permit question. If the replacement requires any change to the rough opening, the permit conversation starts.

The Four Variables That Push a Project Out of Permit-Exempt Territory

We have learned to give San Francisco homeowners a simple test before any window or door project begins. Four variables decide whether a replacement stays in the permit-exempt lane or crosses into full review. None of these are obscure; they are the exact points a DBI plans examiner checks first. Here they are, in the order we ask them.

1. Operating type. Does the new window or door open the same way the old one did? A double-hung for a double-hung is fine. A slider for a double-hung is a change, and it matters because the opening affects egress, ventilation, and sometimes fire department access. The Noe Valley example from our opening is real: a wood double-hung replaced with a vinyl slider in the same rough opening still triggered a Title 24 review because the glazed area and vent area changed enough to matter.
2. Opening dimensions. Are you changing the size of the hole in the wall or the floor? Even adding four inches of height to bring more light into a kitchen means new header work, new framing, possibly new shear requirements, and definitely a permit. Same for widening a patio door opening. In San Francisco, where many homes are wood-framed over a garage or on a slope, changing a header is never a paper-free task.
3. Glazing type and area. Moving from single pane to double pane is usually a good thing, but it changes U-factor and solar heat gain characteristics. The energy code cares, and in Climate Zone 3, which covers San Francisco, the 2026 requirements are specific enough that a plans examiner will ask for the NFRC label data. We cover the exact numbers in the next section.
4. Egress compliance. Any window in a sleeping room must meet minimum clear opening requirements for emergency escape. If you replace a window that currently meets egress with one that does not, even if it fits the same opening, DBI will require correction. Older San Francisco homes in neighborhoods like Bernal Heights or Glen Park often have second bedrooms that predate modern egress rules, and a replacement window that makes an already non-compliant situation worse creates a genuine life-safety issue.

If any of these four variables changes, you are likely in permit territory. The permit itself is not a punishment; it is the mechanism that gets an inspector to confirm the work is safe and the paperwork that protects you if you ever sell the house.

Title 24 Energy Requirements for San Francisco in 2026: U-Factor and SHGC Explained

California’s Title 24 energy code sets mandatory performance levels for windows and doors installed in residential buildings. San Francisco sits in Climate Zone 3, which is the mild, fog-influenced coastal band. For replacement windows in 2026, the maximum U-factor allowed is 0.30, and the maximum SHGC, or solar heat gain coefficient, is 0.23. Those two numbers, printed on the NFRC label that comes on every serious window, are the first thing a plans examiner checks against Title 24.

Here is how to read the label, because we have watched a lot of homeowners stand in a showroom holding a spec sheet they do not quite trust. U-factor measures how well the window resists heat flowing through it. Lower is better in San Francisco, where indoor heat has a habit of escaping through glass on foggy nights. SHGC measures how much solar radiation the window lets in. The 0.23 maximum reflects San Francisco’s mix: we want some passive heat on sunny days in the Mission or Potrero Hill, but not so much that a west-facing room becomes unbearable in late afternoon.

A few practical notes from the field. First, double-pane with low-e coating is the standard way to hit both numbers in San Francisco’s climate. Second, if your project involves enough windows to count as a major alteration, Title 24 may require a full energy compliance document, usually prepared by a certified energy analyst or a contractor who holds the right certification. Third, and this catches some homeowners, Title 24 compliance is separate from the building permit but triggered by it. You cannot close a permit for windows that required a Title 24 review without the energy paperwork being accepted.

When we plan a Window Replacement in San Francisco, we pull the NFRC data for each of our eight manufacturer lines, including PGT and CGI, before quoting. That way the window we recommend for a foggy Outer Sunset living room is the one that actually meets the code, not the one that was easiest to order.

San Francisco DBI’s Permit Process for Windows and Doors: Forms, Timelines, and What to Expect

San Francisco’s Department of Building Inspection processes window and door permits differently depending on scope. For a straightforward project in a non-historic district, where the only changes are the four variables we covered, the process is often relatively quick. But “relatively quick” in San Francisco still means paperwork and a fee, and we want homeowners to see the path clearly before they commit.

1. Determine if a permit is needed. The four-variable test above is the first screen. If you are unsure, DBI’s permit counter can answer questions, though wait times vary and a contractor who works in the city daily will usually know the answer faster.
2. Prepare the application. DBI uses Form 3, the building permit application. For windows and doors, you will list the scope, the number and type of units, the address, and the estimated cost. San Francisco uses permit valuation, meaning the fee is based on the stated cost of the work. Understating the cost to save a few dollars on a permit is a mistake; DBI can and does adjust valuations.
3. Submit plans if required. A like-for-like swap that still needs a permit for another reason often requires minimal drawings: window schedules, sizes, and product data. A project that changes openings, headers, or egress will need architectural drawings and structural calculations. At this point it moves from over-the-counter to plan check.
4. Pay the fees. Plan check fees and permit fees are separate. A basic window permit might run a few hundred dollars in fees alone. A more involved project can push closer to a thousand before any work begins.
5. Wait for review. Simple permits can be issued over the counter the same day if the paperwork is right. Plan check for a window-and-door scope that requires structural or historic review typically takes two to six weeks in our experience, though DBI times change with workload. Residential projects in San Francisco currently move faster than commercial, but “faster” is relative.
6. Schedule inspections. After installation, DBI requires an inspection before the permit can be finalized. For windows and doors, the important check is usually rough framing, if any new framing was done, followed by a final inspection that confirms the installed units match the approved plans.

Our Window Installation in San Francisco work always accounts for the permit path before the first tool comes out, because a project that cannot pass inspection is not a finished project in this city.

Historic District Overlays in San Francisco: How Planning Review Changes the Permit Path

San Francisco layers an extra review on top of DBI when a property sits within a designated historic district or a Planning Department context district. The Alamo Square context district is the one most people picture, with its rows of Victorians and postcard views, but the overlay extends much further: the Castro, Duboce Triangle, parts of the Mission, Jackson Square, and stretches of Russian Hill all carry design review requirements for exterior changes. If you live in one of these districts, a window or door replacement that would be over-the-counter in the Outer Sunset becomes a Planning Department matter here.

What the Planning Department reviews is not the same as what DBI reviews. Planning cares about the building’s appearance: muntin profiles, frame material, sash pattern, depth of the reveal, and whether the replacement matches the original or the district’s prevailing character. A homeowner in the Castro who wants to replace wood double-hungs with vinyl sliders will likely be told to reconsider. Vinyl frames read differently at the sill and at the meeting rail, and in a district where the streetscape is part of the city’s identity, that difference matters. Wood, fiberglass, or aluminum-clad wood that matches the original profile is often acceptable, but “often” is not “always,” and the only way to know is to ask.

The process works like this: DBI receives the permit application, identifies the property as within a planning overlay, and routes it to the Planning Department for what is called a site permit or a neighborhood notification review. The Planning review runs parallel to or ahead of the building review, and it can add two to eight weeks to the timeline. The good news is that most window and door replacements in these districts are handled as administrative review rather than full discretionary review, which means no public hearing and a decision based on published design guidelines. The better news is that a contractor who works in these neighborhoods routinely knows, before filing, which products will pass. We carry ES Windows and ViewLux specifically because their profiles and finish options fit the character of San Francisco’s older districts, and the product data is usually enough to get a clean Planning sign-off.

For Door Installation in San Francisco in a historic district, the review is similar. The Planning Department wants to see a door that matches the original proportions, panel pattern, and glass-to-wood ratio. A modern fiberglass door with a large single lite is almost always a nonstarter in the Alamo Square or Duboce Triangle context. A Therma-Tru door with the right panel configuration and paint color can pass without comment. The difference is preparation, and preparation starts with someone who knows the district guidelines.

Closing the Permit: Why a Signed-Off Permit Card Is Non-Negotiable

The most dangerous moment in any San Francisco window or door project is not the tear-out or the installation. It is the moment the crew packs up and someone suggests the permit can be closed later. A permit that was pulled but never finalized, with no final inspection and no signed-off permit card, sits open in DBI’s records. It becomes a problem when you sell the house, when you refinance, when you make an insurance claim, or when a neighbor files a complaint and the city comes looking.

An open permit means the city never verified the work. It means the work is not legally complete. And in San Francisco, where real estate transactions are scrutinized by buyers’ agents and attorneys who pull city records as a matter of course, an open permit from a window job three years ago can delay a closing or force a price concession. The seller has to hire someone to reopen the job, schedule the missing inspection, and hope the work passes after the fact.

Who is responsible? The homeowner, legally. The permit is in the property owner’s name, and the city does not care that your contractor said he would handle it. That said, a professional contractor closes permits before final payment, and you should never release the final check until you have a copy of the signed-off permit card in hand. The Cedarwell Care Promise that Lightwell operates under includes exactly this expectation: the job is not done until the permit is closed, the inspection is passed, and the homeowner has the paper to prove it.

Insurance exposure is another reason to insist on closure. If a window installed under an open permit fails and causes damage, your insurer may ask whether the work was ever inspected and approved. An honest no is a difficult position. A signed-off permit card is the documentation that the work met the code at the time it was done, and it shifts the liability conversation meaningfully.

Common Mistakes to Avoid

• Assuming every window swap is permit-free. The like-for-like exemption is real, but it is narrower than most people expect. The four-variable test we outlined above is the screen; if any variable changes, the permit requirement kicks in, and guessing wrong stalls the job.
• Understating the project cost on the permit application. DBI valuations are not a suggestion. Listing a $9,000 window replacement as $2,000 to trim the permit fee is a false statement on a public document, and the city does adjust valuations when the scope is obvious.
• Skipping the historic review in a Planning overlay district. Replacing windows in the Castro, Duboce Triangle, or Alamo Square without checking the Planning Department’s requirements is a good way to do work twice. The review is not optional if the property is flagged.
• Ignoring Title 24 until after installation. The energy compliance document is not a box to check at the end. It identifies which windows can be ordered in the first place, and a non-compliant window installed before review is a bigger problem than one caught on paper.
• Accepting a “we’ll close it later” handshake on permits. An open permit is a liability that compounds over time. Get the signed-off permit card before final payment, no exceptions.
• Ordering a door or window by look rather than by NFRC data. In San Francisco’s Climate Zone 3, a beautiful window that misses the U-factor or SHGC limit will not pass plan check. The NFRC label is the deciding document, not the brochure.
• Replacing egress windows without checking the clear opening. Sleeping rooms have mandatory escape dimensions. Shrinking the clear opening even slightly can create a life-safety violation that an inspector will catch at final.

When to Call a Professional

A professional is worth the call when any of the four variables changes, when the property sits in a San Francisco historic district or Planning overlay, or when the last permit on the place was never closed and you need someone to untangle it. Not sure whether to DIY? Read DIY vs Professional Windows & Doors: The San Francisco Homeowner’s Decision Guide. A professional is also worth the call when you want the product recommendation to match the code, the neighborhood, and the house, rather than matching the installer’s preferred vendor. We have carried eight manufacturer brands, including PGT, CWS, and ViewLux, for exactly that reason: one brand is not right for every San Francisco block, and the recommendation should fit the home. Lightwell Windows San Francisco offers free estimates across the city. Call us at (831) 480-4124, and we will walk the property, identify which permit path applies, and put a written price in your hands before any work starts.

Frequently Asked Questions

The Bottom Line

California’s window and door permit rules are not arbitrary, but they are easy to misread. The line between a permit-free like-for-like swap and a full permit project runs through four variables: operating type, opening dimensions, glazing type, and egress. San Francisco adds two more layers: Title 24 energy compliance in Climate Zone 3, and Planning Department design review in the city’s historic districts. The difference between knowing your category before you start and discovering it mid-project is measured in weeks and dollars. Ask the questions early, get the permit path in writing, and never accept a finished job without a signed-off permit card. That is the whole game.

Written by Keith Yamada, Owner at Lightwell Windows San Francisco, serving San Francisco since 2010.