Buying a Rental Property in San Jose or the East Bay: What to Check First

Oct 19, 2026 · By Oanh Nguyen · Broker & Loan Officer · Investing

Investors ask me about rentals here often. Some are buying their first rental. Others already own a few and want to add more.

I also invest in real estate myself. I have bought, remodeled and held property. So I know this: the numbers have to work on paper first. A property that looks great in photos can be a poor fit once you add up the real costs.

I can't tell you whether a property is a good investment for you. That depends on your finances, taxes and goals. A CPA, a real estate attorney and a financial advisor should be part of your team.

What I can do is show you how to look at a property, which numbers to gather and what to check before you buy. That is what this post covers.

Start With Your Goals

Before you look at any property, get clear on what you want. Investors have different goals:

• Monthly income. Rent that covers costs, with money left over.
• Long-term ownership. Holding a property for many years.
• A future home. Renting it out now, and maybe living in it later.
• Diversification. Adding real estate to other investments.

Your goals shape which properties make sense. They also shape how you finance them and how you plan for taxes. Talk them through with your CPA and financial advisor first.

How Cap Rate Math Works

Cap rate is a quick way to compare rental properties. The formula:

Cap rate = Net operating income ÷ Purchase price

Net operating income (NOI) is yearly rent minus yearly operating costs. Operating costs include property taxes, insurance, repairs, HOA dues and management. NOI does not include your mortgage payment.

A hypothetical example

These numbers are made up to show the math. They are not real rents, prices or returns for any area.

• Hypothetical purchase price: $1,000,000
• Hypothetical yearly rent: $48,000
• Hypothetical yearly operating costs: $18,000
• NOI: $48,000 − $18,000 = $30,000
• Cap rate: $30,000 ÷ $1,000,000 = 3.0%

Then compare that to your financing costs, your other options and your goals. Your CPA and advisor can help with that part.

What Cap Rate Doesn't Tell You

Cap rate is a helpful first look. But it leaves a lot out.

• It ignores financing. Your loan terms affect your monthly cash flow a lot.
• It assumes the rent is right. If the rent estimate is too high, the cap rate is wrong.
• It assumes the costs are complete. Missing costs make a property look better than it is.
• It ignores vacancy. Units can sit empty between tenants.
• It ignores big future repairs. A new roof or major system can cost a lot in one year.
• It ignores taxes on your income. Your CPA can explain how rental income is taxed for you.

Use cap rate to compare properties. Don't use it alone to decide.

Gathering the Real Numbers

Good decisions start with good numbers. Here is what I help investors gather.

Rent. Current leases, plus recent rentals of similar units nearby. Don't rely on a seller's projection.

Property taxes. Remember that taxes are usually reassessed when you buy. I cover this in my property tax post. Check with the county assessor.

Insurance. Get a quote for a rental policy, called a landlord or dwelling policy. It is different from a regular homeowners policy.

HOA dues. If any, and any planned increases or assessments.

Repairs and upkeep. Look at the age of the roof and major systems. Set aside money for repairs.

Management. If you won't manage the property yourself, get a quote from a property manager.

Vacancy. Plan for some time between tenants.

Utilities. Know which ones you pay and which ones tenants pay.

Rent and Tenant Rules: Check Before You Buy

California and many cities have rules about rent increases, evictions and tenant protections. The rules can depend on the property type, its age, how many units it has and who owns it. They also change over time.

I don't give legal advice, so I won't summarize these laws here. Instead, I make sure investors know where to look and who to ask:

• The State of California. The Attorney General's office has consumer information on rent increase limits.
• The city. San Jose, Hayward and other cities have their own housing departments and programs. Hayward has an online database to look up a specific address.
• The county. For unincorporated areas like Castro Valley, check with Alameda County.
• A real estate attorney. To explain how the rules apply to a specific property, lease and tenant.

Always check the rules for the specific property before you remove contingencies. They can affect your income and your plans.

Buying a Property With Tenants in Place

Some rentals come with tenants already living there. That can be a plus: you have income from day one. It also comes with homework.

• Read every lease. Know the rent, the term, deposits and any special terms.
• Ask for a rent roll. A list of units, rents and lease dates.
• Ask for tenant estoppel letters if possible. These are statements from tenants confirming their lease terms. Ask your attorney if they make sense for your deal.
• Understand showing rules. Tenants have rights about entry. Inspections and showings need to follow the rules and the lease.
• Plan your first steps as owner. Who collects rent, handles repairs and communicates with tenants.

A real estate attorney can review the leases and explain your obligations.

Common Investor Mistakes I See

These are the mistakes that hurt investors most. All of them are avoidable.

Trusting projected rents. A listing's "potential rent" is not a lease. Verify with real leases and real comparable rentals.

Leaving out costs. Forgetting insurance, repairs, vacancy or management makes any property look better on paper.

Using the seller's tax bill. Your taxes will likely be different after the purchase.

Skipping the rules. Rent and tenant rules can change your income and your plans. Check them for the specific property.

Underestimating repairs. Older rentals often need more work than buyers expect.

Stretching too far. Keep reserves for repairs and vacancies. Surprises happen.

Remodeling or Updating a Rental

Some investors plan to update a property before renting it. Plan that work carefully before you buy.

• Get bids from licensed contractors. Before you remove contingencies, if possible.
• Check permit needs. Ask the city what permits the work requires.
• Plan for time. A rental that is under construction isn't earning rent.
• Ask about existing tenants. If tenants live there, an attorney can explain the rules for repairs and access.
• Ask your CPA how the costs are treated. Repairs and improvements can be treated differently for taxes.

Financing a Rental

As a loan officer, I see investors surprised by financing more than anything else. Loans for rental properties often have different requirements than loans for a home you live in. Down payment, reserves and how rental income is counted can all differ.

I can walk you through the options, or work with your lender. Start this conversation early, before you make offers.

My Checklist for Investor Buyers

1. Set your goals. With your CPA and financial advisor.
2. Get financing lined up. Know your terms before you shop.
3. Verify actual rents. Use current leases and recent comparable rentals, not projections.
4. Get real operating costs. Pull the tax bill, get an insurance quote and look at repair history.
5. Check rent and eviction rules. State, city and county, with an attorney's help.
6. Review existing leases. Know what you are taking over.
7. Inspect thoroughly. Rentals often need more repairs than you expect.
8. Run it past your CPA and attorney. Before you remove contingencies.

A Hypothetical Example

This example is made up to show the process. It is not based on any real property or client.

An investor finds a duplex. The listing shows rents that would make the numbers look strong.

The investor asks for the leases and finds the actual rents are lower than the listing suggests. They get a landlord insurance quote, check the property tax bill and ask a property manager for a fee quote.

Then they check the city's rent rules for that address and ask a real estate attorney to review the leases. With real numbers and clear rules, they decide whether the property fits their goals.

Frequently Asked Questions

The Bottom Line

A rental property can be part of a long-term plan. But it has to make sense with real numbers, real rules and real professional advice.

Start with your goals. Get financing lined up. Gather actual rents and actual costs. Check the rent and tenant rules for the specific property with the city and an attorney. Then review everything with your CPA before you commit.

Buy a rental with your eyes open. I never promise rental income, cash flow or appreciation. No one can. What I can do is help you find the facts and ask the right questions.

Where to Look Up Rent Rules

• California Attorney General, Limits on Rent Increases: https://oag.ca.gov/rentcaps
• City of San José Housing Department, Rent Stabilization: https://www.sanjoseca.gov/your-government/departments-offices/housing/tenants/learn-about-rent-stabilization
• City of Hayward, Information for Landlords: https://www.hayward-ca.gov/services/city-services/information-landlords
• City of Hayward, Rent Review Database: https://hayward-ca.gov/residents/housing/rent-review-database

Sources

• California Attorney General, "Limits on Rent Increases" (published/modified July 16, 2026): https://oag.ca.gov/rentcaps
• City of Hayward, Information for Landlords (accessed October 26, 2026): https://www.hayward-ca.gov/services/city-services/information-landlords

Thinking about a rental property? Call or text me at 408-780-1188, or email onrealtygroup@gmail.com.

Oanh Nguyen · Broker & Loan Officer · On Realty Group, brokered by LPT Realty · BRE #02133991 · NMLS 2020335

Equal Housing Opportunity.

Disclaimer: This post is general information only, not legal, tax, financial or investment advice; consult a CPA, real estate attorney and financial advisor before buying investment property.