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If you own a multi-unit building in San Francisco, or you're trying to buy one, a generic national cap rate calculator won't get you far. It doesn't account for rent control, doesn't know your building might need a soft story retrofit, and has no idea a building in the Marina trades differently than one in the Bayview.
This is a general guide to how San Francisco multi-unit buildings get valued, for owners weighing a sale, hold, or refinance and for investors underwriting a purchase: the core formulas, the San Francisco factors that shift price, and real local transactions so you can see the math applied to buildings that closed.
Allison Chapleau specializes exclusively in San Francisco multi-unit properties, with more than 24 years of San Francisco multi-unit and commercial sales experience and 300+ multi-unit and mixed-use buildings sold [1]. The Off Market Podcast introduced her as having closed well over $1 billion in property [2]. If you'd rather skip straight to real numbers, you can request a San Francisco property valuation directly.
What "Value" Means for a San Francisco Multi-Unit Building
Appraisers lean on three approaches to value: the cost approach (rebuild cost), the sales comparison approach (what similar properties sold for), and the income approach (what cash flow says it's worth). For San Francisco apartment buildings, the cost approach rarely matters. The income and sales comparison approaches do the real work.
Which one carries more weight depends on building size. A 2-4 unit building in San Francisco is usually valued like a single-family home: pull recent comps and adjust for condition, unit count, and location. Owner-users compete alongside investors, and lenders often use residential-style financing, so comps carry heavy weight.
A 5+ unit building shifts the calculation toward income. These properties trade in the commercial financing world, where NOI relative to price drives the conversation and comps mainly sanity-check that number. If you own a smaller building, this breakdown of owner-occupied multi-unit properties in San Francisco covers how that segment behaves differently.
The Core Formulas: NOI, Cap Rate, and GRM for San Francisco Buildings
Three numbers drive almost every San Francisco multi-unit conversation.
Net operating income (NOI) is annual income after operating expenses, before debt payments: gross rental income minus property tax, insurance, repairs, and management. Mortgage payments and capital improvements aren't included.
Cap rate measures NOI against property value. Per JPMorgan Chase's overview of how cap rates work, cap rate equals NOI divided by property value or price. JPMorgan's example: a property worth $14 million generating $600,000 of NOI has a cap rate of 4.3% [3]. Flip it around and divide a building's NOI by a market cap rate to estimate value.
Gross rent multiplier (GRM) is quicker and rougher. Per JPMorgan Chase's breakdown of the gross rent multiplier formula, GRM is price divided by annual gross rent, before expenses. A lower GRM generally signals a better estimated return [4].
Cap Rate vs GRM: When to Use Which in San Francisco
GRM is fast: two numbers, done, a useful first filter across San Francisco listings. But it ignores operating expenses, which vary widely between a well-maintained building and one carrying deferred maintenance or a looming soft story retrofit.
Cap rate takes more work since it needs real expense figures, but it's more precise since it's built on NOI. The JPMorgan report above put the San Francisco multifamily cap rate at 4.50% as of the fourth quarter of 2025, unchanged from the fourth quarter of 2024 [3], one dated data point, not a claim about today's market. Cap rates move with interest rates, class, condition, and neighborhood, so treat 4.50% as a reference point, not a guarantee. Our San Francisco multi-unit market reports track how these figures shift.
Buyers typically use both together: GRM narrows the list, cap rate does the underwriting.
A Hypothetical San Francisco Valuation Walkthrough
Before going further: what follows is a hypothetical, illustrative example built on round numbers. It is not a real transaction, and none of the figures below describe an actual San Francisco property.
Say you're looking at a 6-unit building. Each unit rents for $2,500 a month, giving gross annual rent of $180,000. Apply an illustrative 35% expense ratio, and expenses come to $63,000 a year, leaving NOI at $117,000.
Apply an illustrative 5% cap rate: $117,000 divided by 0.05 equals $2,340,000, your estimated value using the income approach. The GRM on the same numbers, $2,340,000 divided by $180,000, equals 13.
Now raise each unit's rent by $200 a month. New rent per unit is $2,700, so six units brings gross annual rent to $194,400. At the same expense ratio, NOI rises to $126,360, and at the same cap rate, value climbs to $2,527,200, roughly $187,200 higher from that rent bump alone. The GRM stays at 13, since it only reflects price against gross rent when cap rate and expense ratio hold steady, a sign that GRM alone won't capture everything a rent increase does to value.
Again, this whole example is hypothetical. Real San Francisco buildings carry rent-controlled units, uneven expense histories, and cap rates that shift by neighborhood and condition, so an actual valuation needs real numbers, not round figures.
San Francisco-Specific Factors That Move the Price
Rent Control's Effect on In-Place Income in San Francisco
San Francisco's Rent Ordinance covers many residential units built on or before June 13, 1979 [5]. Under the ordinance, a landlord can raise a covered tenant's rent only once every 12 months, by the allowed percentage the Rent Board sets each year. Per sf.gov, the current allowable rent increase is 1.6%, effective March 1, 2026 through February 28, 2027 [6].
That limit matters for valuation. A tenant who's stayed a decade or more may pay well below what the unit would fetch today, suppressing current NOI relative to the building's real income potential. Sophisticated buyers underwrite both in-place NOI and market, or pro forma, NOI based on what units could fetch after turnover.
The Mandatory Soft Story Retrofit Program and San Francisco Underwriting
San Francisco's Mandatory Soft Story Retrofit Program covers wood-frame buildings with five or more residential units and two or more stories over a soft or weak story, permitted for construction before January 1, 1978 [7]. If your building fits that and hasn't been retrofitted, a lender and insurer will want to know.
The city's Community Action Plan for Seismic Safety (CAPSS) analysis, referenced on the City's Earthquake Safety Implementation Program soft story page, estimated that these retrofits would cost between $60,000 and $130,000, depending on the building size [7]. That is an older city estimate, and current costs can differ, but the range shows why buyers price an unfinished retrofit into their offer or negotiate a credit at closing.
Neighborhood and District Price Variation Across San Francisco
Location has always shaped San Francisco real estate. Proximity to transit, employment centers, and retail districts tends to support stronger demand, while less central pockets of the city see more variability in buyer interest and financing terms. Since these differences shift by district and over time, our San Francisco multifamily market insights page is the better place for current, neighborhood-level detail.
The Comparable Sales Approach: Reading Recent San Francisco Deals
Real transactions tell you more than any formula alone. 691 Post Street, a 36-unit mixed-use building in Downtown San Francisco, sold for $9,000,000 at a 4.32% cap rate and a 12.73 gross rent multiplier. The annual income at the time was $746,095 and the price per unit was $263,889 [8].
Larger and smaller buildings tell different stories. 625 Scott Street, a 42-unit building across from Alamo Square, sold for $18,050,000 in August 2022 [9], which The Real Deal reported as San Francisco's biggest multifamily deal of 2022 [10]. On the smaller end, 335 2nd Avenue, a 10-unit building in the Richmond District, sold for $3,670,000, $370,000 over the list price, with multiple offers [11].
These three deals show how differently size and positioning play out within the same market. Pricing, financing pools, and timelines all varied by size and location. For more, see our notable San Francisco multi-unit building sales and recently sold San Francisco apartment buildings.
Common Valuation Mistakes San Francisco Buyers and Sellers Make
A few mistakes come up again and again in San Francisco multi-unit deals:
- Relying only on in-place NOI. Long-tenured, rent-controlled tenants can make in-place NOI understate a building's real capability after turnover.
- Assuming a low cap rate means a bad deal. A lower cap rate often reflects a stronger location or better condition, not a bad price. Read it alongside comps in the same district.
- Treating GRM and cap rate as interchangeable. GRM ignores expenses. Two buildings with identical GRMs can have very different NOI once costs are factored in.
- Underestimating tenant turnover effects. Turnover can drive the biggest NOI gains, but it can take years, and buyers need to underwrite that timeline realistically.
- Forgetting soft story costs. An unaddressed retrofit obligation isn't a minor line item. The city's older CAPSS estimate put it at $60,000 to $130,000 depending on building size [7], enough to change what a buyer will pay.
How to Get an Accurate Value for Your San Francisco Building
Start with recent comparable sales similar in size, condition, and location to yours. Then run the income approach using your actual rent roll and operating expenses, not estimates, and cross-check the two. A gap between them usually points to below-market rents, deferred maintenance, or an unusual expense ratio.
A professional valuation from an agent like Allison Chapleau who works exclusively in San Francisco multi-unit property [1], rather than a generalist, will catch what a generic estimate misses: which comps are truly comparable, how a soft story obligation should be priced, and what your in-place versus market rent gap is worth. As the top multi-unit Realtor in San Francisco [12], Allison Chapleau has sold 300+ multi-unit and mixed-use buildings [1] and works across all 10 San Francisco districts [12].
Frequently Asked Questions About Valuing a San Francisco Apartment Building
What is a good cap rate for an apartment building in San Francisco?
There's no single "good" cap rate for every San Francisco building. As a dated reference point, JPMorgan Chase put the San Francisco multifamily cap rate at 4.50% as of the fourth quarter of 2025, unchanged from a year earlier [3]. Cap rates vary by class, condition, and district, so compare against real San Francisco comps.
What is GRM in real estate and how do I calculate it for my San Francisco building?
Gross rent multiplier is price divided by annual gross rent, before expenses [4]. For a San Francisco building, divide the sale price or estimated value by the rent it collects in a year. It's a fast filter, but it won't account for actual operating costs.
How does rent control affect the value of a San Francisco apartment building?
San Francisco's Rent Ordinance covers many residential units built on or before June 13, 1979 [5], and limits increases for covered tenants to once every 12 months at the Rent Board's allowed percentage, currently 1.6% through February 28, 2027 [6]. Long-tenured tenants often pay well below market rent, suppressing in-place NOI, so San Francisco buyers underwrite both in-place and market rent scenarios.
Does the Mandatory Soft Story Retrofit Program affect what my San Francisco building is worth?
Yes, if it's a wood-frame building with five or more residential units and two or more stories over a soft or weak story, permitted for construction before January 1, 1978, and not yet retrofitted [7]. The city's older CAPSS analysis estimated retrofit costs between $60,000 and $130,000 depending on building size [7], a range buyers factor into their offer or a closing credit.
What's the difference between valuing a 2-4 unit building and a 5+ unit building in San Francisco?
A 2-4 unit San Francisco building is valued like a home, using comps and appraisal-style adjustments, since owner-users compete alongside investors. A 5+ unit San Francisco building leans on the income approach, since these deals trade primarily on NOI and cap rate.
How do I find comparable sales for my San Francisco apartment building?
Look for recently sold San Francisco buildings similar in unit count, condition, and neighborhood, and compare price per unit, price per square foot, and cap rate, not just sale price. An agent with direct transaction history, like Allison Chapleau's notable San Francisco multi-unit building sales, can pull truly comparable deals.
Should I get a professional appraisal before selling my San Francisco multi-unit building?
It's a reasonable step, especially for 5+ unit San Francisco buildings where NOI, expenses, and rent-control status need documentation. Many owners pair a formal appraisal with a market-based valuation from an agent who actively sells San Francisco multi-unit buildings.
How much does location within San Francisco affect an apartment building's value?
Quite a bit. Proximity to transit, employment centers, and retail corridors supports stronger demand, while less central San Francisco neighborhoods see more variability in buyer interest and financing terms. District rent potential and turnover speed differ block by block.
What happens to my building's value if I inherit it through probate in San Francisco?
Inherited San Francisco multi-unit buildings often carry below-market rents if tenants have stayed for years, widening the in-place versus market NOI gap. A probate sale still needs a defensible valuation, using comps and income data, before the building is listed or transferred.
How often do cap rates and GRMs change in the San Francisco multifamily market?
Both move with interest rates, buyer demand, and economic conditions. The 4.50% San Francisco multifamily cap rate held steady between the fourth quarter of 2024 and the fourth quarter of 2025 [3], but that stability isn't guaranteed going forward, and individual building rates vary by condition, class, and district.
If you're weighing whether to sell, hold, or refinance a San Francisco multi-unit building, or underwriting a purchase, request a San Francisco property valuation from Allison Chapleau's team, or read more about Allison Chapleau, San Francisco multi-unit broker and her track record of 300+ multi-unit and mixed-use buildings sold [1].
Sources
- Allison Chapleau, homepage: "Allison Chapleau specializes exclusively in San Francisco multi-unit properties," "24+ yrs San Francisco multi-unit and commercial sales experience," "300+ Multi-unit and mixed-use buildings sold." https://www.allisonchapleau.com/
- Off Market Podcast, "From Surfing to $1B in Sales: How Allison Chapleau Became San Francisco's Top Multi-Unit Agent" (Goliath Data). https://goliathdata.com/from-surfing-to-1b-in-sales-how-allison-chapleau-became-san-francisco-s-top-multi-unit-agent
- J.P. Morgan, "Cap rates explained" (cap rate formula example; sample cap rates, San Francisco multifamily, 4Q 25 and 4Q 24). https://www.jpmorgan.com/insights/real-estate/commercial-term-lending/cap-rates-explained
- J.P. Morgan, "What is a gross rent multiplier (GRM)?" https://www.jpmorgan.com/insights/real-estate/commercial-term-lending/what-is-a-gross-rent-multiplier-grm
- City and County of San Francisco, Rent Board, "Learn about San Francisco rental laws." https://www.sf.gov/learn-about-san-francisco-rental-laws
- City and County of San Francisco, Rent Board, "Learn about rent increases in San Francisco." https://www.sf.gov/learn-about-rent-increases-san-francisco
- City and County of San Francisco, Earthquake Safety Implementation Program, "Soft Story." https://www.sfgov.org/sfc/esip/soft-story
- Allison Chapleau, 691 Post Street listing ($9,000,000; 4.32% cap rate; 12.73 GRM; annual income $746,095; $263,889 per unit). https://www.allisonchapleau.com/listing/691-post-street
- Allison Chapleau, 625 Scott Street listing (sold August 2022, $18,050,000). https://www.allisonchapleau.com/listing/625-scott-street
- The Real Deal, "Alamo Square Trophy Property is San Francisco's Biggest Multifamily Deal of 2022," August 9, 2022. https://therealdeal.com/san-francisco/2022/08/09/sfs-biggest-multifamily-sale-this-year-totals-18m/
- Allison Chapleau, 335 2nd Avenue listing ($3,670,000; sold $370,000 above the list price; multiple offers received). https://www.allisonchapleau.com/listing/335-2nd-avenue
- Allison Chapleau, About page: #1 listing agent in San Francisco by number of 2-4 unit listings, 2021 to 2025 (78 vs 36), and by number of 5+ unit listings (115 vs 92), per Broker Metrics, San Francisco MLS data 1/1/21 to 12/31/25; "specializes in selling 2-4 unit, 5-14 unit, and larger multifamily properties across all 10 San Francisco districts." https://www.allisonchapleau.com/about/allison-chapleau. Also listed on her Compass agent profile as "#1 Listing Agent 2-4 Units and 5+ Units in San Francisco 2015-present (MLS)." https://www.compass.com/agents/allison-chapleau/
