Will a remodel raise my property taxes in California?
In California, a like-for-like remodel usually does not raise your property taxes. Under Proposition 13, only new construction is reassessed, and even then only the added value is taxed — at roughly 1.1% to 1.25% a year in Los Angeles County — while the rest of your home keeps its old, lower base-year value. Repainting, new cabinets, a new roof, or a kitchen or bathroom updated inside its existing footprint count as repair and maintenance and are not reassessed. What does get reassessed is new square footage — a room addition, a second story, or an ADU — valued at what that new space adds to market value, not what it cost to build. So a $150,000 addition that adds about $150,000 of value raises your tax bill by roughly $1,650–$1,900 a year, while the original house is left untouched.
Adding square footage in California reassesses only the new part, at its added value — not a whole-house reappraisal, and not based on what you spent.
The Proposition 13 rule, in one sentence
Proposition 13 froze your home's assessed value at its base-year value — usually what you paid when you bought it — and lets it rise no more than 2% a year, regardless of what the market does. A remodel does not undo that. The only thing that gets newly assessed is new construction you add, and only for what that new construction adds to market value. Everything you already own keeps its old, low base.
That single mechanic explains almost every property-tax question a homeowner has about remodeling.
What triggers a reassessment — and what doesn't
| Project | Reassessed? | What gets taxed |
|---|---|---|
| Paint, flooring, roof, windows (like-for-like) | No | Nothing — repair & maintenance |
| Kitchen or bath remodel in the existing footprint | No | Nothing, if it's a refresh not a rebuild |
| Room addition, bump-out, second story | Yes | Only the value the new space adds |
| ADU or garage conversion | Yes | Only the value the new unit adds |
| New pool, or converting a garage to living space | Yes | Only the added value |
| Seismic retrofit, solar, disabled access | No | Excluded by statute |
These are how California property-tax law treats each project — general rules, not a quote or tax advice. Your county assessor makes the final call.
The math, with real numbers
In most Los Angeles County tax rate areas, the total rate is about 1.1% to 1.25% of assessed value a year: the 1% Proposition 13 base plus local voter-approved bonds and assessments. Apply that only to the added value.
- A $150,000 addition that adds roughly $150,000 of market value → about $1,650–$1,900 a year in new tax.
- A $250,000 ADU that adds roughly $250,000 of value → about $2,750–$3,100 a year.
- A $90,000 kitchen remodel in the same footprint → $0 in new base tax, because nothing was reassessed.
Notice the kitchen. People assume a big spend means a big tax hike. It doesn't. The tax follows new square footage and new value, not the size of the check you wrote.
The "like new" trap most articles skip
There's one honest caveat. If you take a house down to the studs and rebuild it so thoroughly that the assessor considers it "substantially equivalent to new," that portion can be treated as new construction and reassessed — even without adding square footage. This is rare for a normal remodel and common for a full gut-and-flip. A kitchen or bathroom brought up to date in place is not "like new." Reframing an entire house, replacing all systems, and rebuilding the interior can be. If your project is that deep, ask your assessor's office how they'll treat it before you start.
Value added, not cost spent
The assessor values what the new construction adds to market value, which is not always what it cost. High-end finishes can cost far more than they add; a smart, efficient addition can add more value than it cost. Either way, the assessment is the appraiser's judgment of added market value, and you can appeal it if you think it's wrong.
The exclusions worth knowing
California carves out specific improvements from reassessment on purpose, to encourage them:
- Seismic retrofits — foundation bolting, cripple-wall bracing, soft-story retrofits (R&T §74.5). Notify the assessor within 30 days of completion. See our guide to earthquake retrofit in Burbank and the San Fernando Valley.
- Solar energy systems — active solar is excluded from new-construction assessment.
- Disabled-access improvements — many accessibility upgrades to an existing home are excluded.
If your project includes any of these, they don't add to your tax bill even though they're real construction.
How to plan around it
If you're weighing an ADU or a second-story addition, fold the ongoing tax into your math: figure roughly 1.1%–1.25% of the value the new space will add, per year, and expect a one-time supplemental bill after completion. It's usually a small fraction of the rent an ADU brings in or the value an addition creates — but it's real, it's ongoing, and it's better to see it coming than to be surprised by a supplemental bill eight months after the final inspection.
DN Builders Group Inc is a licensed, bonded general contractor based in Burbank (CA Lic. #1139710). See our home additions & ADUs and whole-home renovation services, or request a walkthrough. This is general information about how California property-tax rules treat construction — not legal, tax, or financial advice. Confirm your situation with the Los Angeles County Assessor. Figures are typical 2026 ranges, not a quote.
Questions
Does a kitchen or bathroom remodel raise property taxes in California?
Generally no, as long as you stay inside the existing footprint. Replacing cabinets, counters, tile, fixtures, and appliances is treated as repair and maintenance, not new construction, so it is not reassessed. Two things change that answer — adding square footage (bumping the room out, or building a whole new bathroom where there wasn't one), or a gut renovation so complete the assessor considers the space "substantially equivalent to new." A normal LA kitchen or bath refresh in place is not a taxable event.
How much will an ADU or room addition add to my property tax bill?
Only the added value is assessed, at roughly 1.1%–1.25% of that value per year in most Los Angeles County tax areas. An ADU or addition that adds about $200,000 of market value raises your annual tax by roughly $2,200–$2,500. Your existing house keeps its Proposition 13 base-year value and is not touched — the assessor blends the two. You will also get a one-time supplemental bill covering the period from when construction finished to the next tax year.
Does an earthquake (seismic) retrofit raise my property taxes?
No. California Revenue & Taxation Code §74.5 specifically excludes seismic retrofitting from reassessment, so bolting your foundation, bracing cripple walls, or a soft-story retrofit does not add to your assessed value. You do have to notify the county assessor of your intent to claim the exclusion before, or within 30 days of, completing the work. Solar energy systems and certain disabled-access improvements are excluded too.
What is a supplemental property tax bill?
When you add new construction, the assessor values the added portion and issues a supplemental assessment effective the month the work is completed. You get a one-time supplemental bill for the added value, prorated for the remainder of the fiscal year, on top of your regular bill. After that, the added value simply rolls into your annual assessment going forward, rising no more than 2% a year like the rest of the property.