California Property Tax Exclusion for Accessibility Improvements: Will a Ramp Raise Your Taxes?

A question I hear all the time from longtime homeowners planning a bathroom remodel or a ramp is whether the work will raise their property taxes. Under Prop 13, new construction is normally assessed and added to your tax bill, and for someone carrying a 1980s assessed value, even a modest bump can feel like a penalty for trying to stay safe at home. California has a property tax exclusion for accessibility improvements, and a second one for seismic retrofits, that most people don’t hear about until after the contractor has gone home. I’m a Certified Aging in Place Specialist (CAPS) and a REALTOR® who has spent more than two decades helping Silicon Valley families decide whether to modify the house or move, and these two exclusions come up in a lot of those conversations. This article is part of my guide to aging in place vs. moving in Silicon Valley. Each county Assessor administers the rules, so confirm the details and filing requirements with the Santa Clara County Assessor (or your own county’s) before you build.

How New Construction Is Normally Assessed

Under Prop 13, your home’s assessed value can only rise by up to 2 percent a year unless there’s a change in ownership or new construction. When you add square footage or make major improvements, the Assessor appraises the new work at its market value and adds that amount to your existing assessed value as a new base year value. The rest of the house keeps its old Prop 13 base, so you aren’t reassessed on the whole home, but you do pay roughly 1 percent or more a year on the added value for as long as you own it. Repairs and normal maintenance aren’t new construction. An addition, a new bathroom, or a significant remodel usually is, and Assessors generally learn about it from the building permit.

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Who Qualifies for the Accessibility Exclusion

Section 74.3 was put in place after California voters approved Proposition 110 in June 1990, and it applies to qualifying work completed on or after June 6, 1990. It says that construction, installation, removal, or modification of an existing single-family or multifamily dwelling isn’t “new construction” for property tax purposes when it’s done to make the home more accessible to a severely and permanently disabled person who lives there permanently. The law defines that person as someone with a physical disability or impairment, whether from birth or caused by accident or disease, including one that affects sight, speech, hearing, or the use of limbs, that limits their ability to work or substantially limits one or more major life activities, and that’s been diagnosed as permanently affecting their ability to function.

A few eligibility details trip families up. The disabled person has to live in the home permanently, but they don’t have to own it, so the exclusion can apply when an adult child modifies their own house so Mom or Dad can move in. The home also has to be owner-occupied and eligible for the homeowners’ exemption. And the exclusion only covers changes to an existing dwelling, so it doesn’t apply to building an entirely new house.

Which Improvements Qualify

The test is whether the work specially adapts the home so the disabled resident can get into it, move around it, and fully use its rooms and fixtures. Improvements that commonly qualify include:

• Ramps and step-free entries
• Widened doorways and hallways
• Grab bars, handrails, and accessible bathroom features, such as a roll-in or curbless shower
• Lowered counters, cabinets, sinks, or switches
• Stair lifts, platform lifts, and elevators installed for accessibility
• In some cases, a bedroom or bathroom that duplicates one the disabled resident can’t otherwise use, such as a main-floor bath when the only full bath is upstairs

The key limit is that the exclusion doesn’t apply to features that are usual or customary in comparable homes without disabled residents, and other work is only excluded if it’s merely incidental to the accessibility improvements. A standard bathroom remodel with nicer tile and new vanities would generally be assessed, while the accessibility-specific portions of the same project may be excluded. Ask your contractor to break out the accessibility items on the bid and the final invoice, because that’s the number the Assessor will want to see. If you’re still pricing the work, my breakdown of what aging-in-place modifications cost in Silicon Valley is a good place to start.

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How to Claim the Exclusion With Form BOE-63

The claim form is BOE-63, the Disabled Persons Claim for Exclusion of New Construction, and it’s the same state form in every California county. Here’s the order I recommend:

1. Call the Assessor before you start. In Santa Clara County that’s the Real Property Division of the Assessor’s Office at 408-299-5300. Ask what documentation they want and when they want it.
2. Pull permits. Permitted work is what triggers the Assessor’s review in the first place, and unpermitted work creates its own problems later. See selling a house with unpermitted work in California.
3. Get the physician’s certification. A licensed physician or surgeon of appropriate specialty has to certify that the resident is severely and permanently disabled and identify the specific needs the work addresses.
4. Describe the work. The claim needs a statement identifying the construction, installation, or modification that was actually necessary to make the home more accessible. Keep plans, permits, itemized invoices, and before and after photos.
5. File the claim. The disabled person, their spouse, or their legal guardian signs the BOE-63 under penalty of perjury. Unlike the seismic exclusion below, the accessibility statute doesn’t spell out a 30-day window, but don’t wait. File as soon as the work is finished so the Assessor doesn’t enroll the added value first. The Assessor may charge a fee to cover processing.

The Seismic Retrofit Exclusion

Many Silicon Valley homes built before modern building codes benefit from seismic retrofits, such as bolting the house to its foundation and bracing cripple walls. Revenue and Taxation Code section 74.5 excludes qualifying seismic retrofitting improvements, and improvements that use earthquake hazard mitigation technologies, from reassessment of an existing building. The rules here are stricter on timing than the accessibility exclusion. You file form BOE-64, the Claim for Seismic Safety Construction Exclusion, with the Assessor before the project is finished or within 30 days of completion, and all supporting documents are due within six months after completion. The owner, contractor, engineer, or architect also has to certify to the local building department which portions of the project are seismic work, and the building department reports those costs to the Assessor. New plumbing, electrical, and finish work done at the same time isn’t excluded.

If you’re already opening walls or working on the foundation as part of an aging-in-place project, it’s worth asking whether seismic work makes sense at the same time. The California Earthquake Authority’s Earthquake Brace + Bolt program has offered grants of up to $3,000 toward a qualifying retrofit in eligible ZIP codes, with registration periods that open and close, so check whether your address qualifies before you hire anyone.

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Don’t Forget the Income Tax Side

The property tax exclusion is only half of the picture. According to IRS Publication 502, the cost of improvements made to your main home to accommodate a disability, such as entrance ramps, widened doorways and hallways, grab bars, lowered cabinets, and modified stairways, generally doesn’t increase the home’s value, so the full cost can count as a medical expense if you itemize deductions. Medical expenses are only deductible to the extent they exceed 7.5 percent of your adjusted gross income, so whether it helps depends on your numbers. Talk to your CPA about how to treat these costs, and keep every receipt either way, since records of what you put into the house also matter for your cost basis and capital gains when you sell.

Other Property Tax Tools for Older Homeowners

• The Prop 19 base-year transfer lets homeowners 55 and older, and severely disabled homeowners of any age, move their Prop 13 assessed value to a replacement home anywhere in California, up to three times. See my guide to the Prop 19 base-year transfer.
• The homeowners’ exemption reduces the assessed value of a primary residence by $7,000. It’s small, but it’s also a requirement for the accessibility exclusion, so make sure it’s on file.
• Property Tax Postponement is a State Controller program that lets homeowners who are 62 or older, blind, or disabled defer current-year property taxes on their home. The Controller’s fact sheet lists a household income limit of $55,181 and requires at least 40 percent equity, and the deferred taxes accrue 5 percent simple interest. The limits change, so check the current rules before you apply.

If the bigger question is how to pay for staying put, see ways to stay in your home without a reverse mortgage.

When the House Is Sold

The accessibility and seismic exclusions protect the owner for as long as they own the home. When the property changes ownership, it’s reassessed at full market value like any other sale, and the buyer starts over with a new Prop 13 base. Well-designed accessibility features can still add appeal at resale, especially a curbless shower or a step-free entry that doesn’t look institutional, and Silicon Valley has a deep pool of buyers shopping for a parent or planning their own next move. See what aging-in-place modifications cost and my guide to aging in place vs. moving in Silicon Valley before you commit to a big project.

Sources and Further Reading

• California Revenue and Taxation Code § 74.3 (disabled access exclusion)
• California Revenue and Taxation Code § 74.5 (seismic retrofitting exclusion)
• California State Board of Equalization, Form BOE-63 (sample)
• Santa Clara County Assessor, Seismic Safety Construction Exclusion BOE-64
• Santa Clara County Office of the Assessor
• California State Controller, Property Tax Postponement Fact Sheet
• IRS Publication 502, Medical and Dental Expenses

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