Andres Diaz

Managing Director, Multifamily Investments · Kingside Investment Group

How Do the 2026 RSO Changes Affect My Apartment Building's Value in Los Angeles?

The RSO's new 4% rent-increase ceiling, effective July 1, 2026, slows projected NOI growth on every pre-1978 building, which compresses terminal value even if today's cap rate holds steady. On a hypothetical 12-unit building, the value gap between the old and new formula can run into six figures over a five-year hold. Non-RSO buildings under AB 1482 keep a higher ceiling and may draw relatively more buyer interest as a result.

Los Angeles apartment building owners have spent the past several weeks digesting what the new RSO formula means for their rent increase notices. That is the compliance question. The value question is separate, and it is the one that actually determines what your building is worth if you list it, refinance it, or simply want to understand where you stand today. A lower ceiling on allowable rent growth does not just change what you can charge a tenant next year. It changes what a buyer is willing to pay for your building right now.

The guide below walks through the mechanism connecting the new RSO formula to your building's value, using a hypothetical worked example to show the dollar impact over a five-year hold. It also covers how non-RSO buildings under AB 1482 are affected differently, and what that gap means if you are weighing whether to sell. This is a companion piece to our guide on how much you can raise rent in Los Angeles in 2026, which covers the compliance mechanics in full. Here, the focus is entirely on what the new formula does to your building's underlying value.

Every number in the worked example below is hypothetical and illustrative only. It is not a valuation of any specific Kingside listing or closed transaction, and it should not be used as a substitute for a written valuation of your actual building.

How a Lower Rent Cap Compresses Your Building's Value

Apartment building value is calculated using the income approach: Value equals Net Operating Income divided by Cap Rate. NOI is gross rental income minus operating expenses, before debt service. This is the formula every institutional buyer, appraiser, and lender uses as the foundation of their analysis (a standard method recognized under the Appraisal Institute's income capitalization guidance), and it is the formula that connects a change in rent control policy directly to a change in what your building is worth.

Here is the part sellers sometimes miss. The RSO formula change does not touch the cap rate itself. Cap rates move based on interest rates, buyer demand, and perceived risk across the broader market, not based on a specific rent control ordinance. Matthews Real Estate Investment Services' Q1 2026 Los Angeles multifamily data put the metro average cap rate at 5.1 percent, a market-wide figure driven by debt costs and investor demand, unrelated to any single building's rent-control status. What the new formula changes is the NOI growth assumption a buyer plugs into their model before they apply that cap rate. A lower ceiling on rent growth means a slower-growing NOI curve over the hold period, and a slower-growing NOI curve produces a lower value at exit, even if the cap rate a buyer applies today is identical to what it would have been under the old formula.

That distinction matters because it explains why two nearly identical buildings, one RSO-covered and one not, can see their values diverge under the new rules without any change in market cap rates at all. The gap comes entirely from the growth assumption, not from a shift in how buyers price risk generally.

What a Hypothetical 12-Unit Building in Los Angeles Looks Like

The example below is entirely hypothetical. It is built to illustrate the mechanism, not to describe any actual Kingside listing or closed transaction. The numbers are chosen to be reasonably representative of a modest RSO-covered Los Angeles multifamily asset, but your building's actual figures will differ.

Assume a hypothetical 12-unit RSO-covered apartment building with a starting Net Operating Income of $300,000 in year one. Assume a buyer is evaluating a five-year hold and is deciding what growth ceiling to model for in-place rent increases. Under the old RSO formula, that buyer could reasonably model growth up to an 8% annual maximum in years where CPI supported it. Under the new formula, effective July 1, 2026, the same buyer can model growth up to only a 4% annual maximum, with a floor as low as 1% in a low-inflation year.

Applying each ceiling as a compound annual growth rate across a five-year hold, the old 8% maximum grows the building's NOI to approximately $440,798 by year five. The new 4% maximum grows the same starting NOI to approximately $364,996 by year five. That is a gap of roughly $75,802 in year-five NOI alone, purely from the change in the formula's ceiling, with no other assumption changed.

Applying a single illustrative cap rate of 4.75%, toward the tighter end of the stabilized mid-tier range around Matthews' cited 5.1% metro average, to each year-five NOI figure produces the terminal value comparison below. This cap rate is chosen purely for illustration and is not a market quote for any specific submarket or property type. Actual cap rates vary by submarket, building condition, unit mix, and prevailing interest rates at the time of sale.

In this hypothetical, the gap between the old-formula terminal value and the new-formula terminal value is approximately $1,595,843, roughly 17% of the old-formula value, driven entirely by the change in the growth ceiling. The cap rate did not move in this comparison. The starting NOI did not move. The only variable that changed was the maximum allowable rent growth rate, and that single variable produced a seven-figure swing in projected terminal value on a modest 12-unit asset.

The $75,802 gap is the number sellers need to internalize. It is not that the RSO change makes your building worthless or unsellable. It is that a buyer running this same math on your actual rent roll will arrive at a lower offer, or a more conservative pro forma, than they would have run a year ago, purely because the ceiling on future income growth is now lower.

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How NOI Compares Year by Year Under the New Formula

The five-year snapshot above tells the terminal value story for a Los Angeles apartment building, but the year-by-year build shows exactly where the two formulas diverge. The gap starts small and compounds every year, which is precisely why a modest change in the annual ceiling produces an outsized effect on a multi-year hold.

Notice that the gap in year one is only $12,000, a relatively minor difference that would not by itself justify significant concern. By year five, the annual gap has grown to $75,802, and the effect on terminal value, once that year-five NOI is divided by a cap rate, is the seven-figure swing shown in the prior section. This compounding effect is exactly why buyers evaluating a longer hold period, five years or more, are the ones most sensitive to the new ceiling. A buyer planning a two-year flip has less exposure to this compounding gap than a buyer planning a seven-to-ten-year hold.

What Changed in the Underwriting Assumption

Before July 1, 2026, a buyer building a pro forma on an RSO-covered Los Angeles building could reasonably model in-place rent growth as high as 8% in a strong CPI year, with a 3% floor in a weak one. That gave buyers a fairly wide band to work with, and in years with elevated CPI, the RSO ceiling was rarely the binding constraint on projected growth. The realistic constraint was usually market rent itself, not the formula.

The new formula flips that relationship for many buildings. A 4% maximum, with a floor as low as 1%, means the RSO formula is now the binding constraint on in-place rent growth in nearly every scenario, regardless of how high CPI runs in a given year. A buyer can no longer count on an 8% year bailing out a slow-growth year elsewhere in the hold period. The ceiling is fixed at 4% no matter what inflation does.

The 4% ceiling changes how sophisticated buyers build their pro forma. Rather than modeling a range that flexes with CPI, buyers are now modeling a flat, dependable 4% ceiling as the realistic upper bound for in-place growth on RSO assets, and building their offer around that fixed number. Sellers who are still thinking in terms of the old 8% ceiling when they set their asking price are working from an outdated assumption that a buyer's underwriting team will correct during due diligence, typically by repricing the offer down toward the 4% ceiling now governing every projected increase.

How This Shows Up in Actual Offers

The mechanism described above is not theoretical. Buyers underwriting RSO deals across Los Angeles today are modeling slower rent growth, and that shows up in one of two ways when an offer lands on your desk. Either the offer price comes in lower than it would have a year ago at the same cap rate, because the buyer's terminal value calculation produced a smaller number, or the offer price stays similar but is built on a materially more conservative growth assumption, which the buyer will flag explicitly during due diligence if your listing materials still reference the old 8% ceiling.

Sellers should expect this to appear directly in offer terms, not just in general market commentary about rent control. A buyer's investment committee or lender is going to run the NOI-over-cap-rate math using the current 4% ceiling regardless of what your listing brochure says, so the disconnect between an outdated asking price and a buyer's actual underwriting becomes visible fast, usually within the first round of offers.

Documentation matters here too. A rent roll showing a clear history of turnover and vacancy decontrol gives a buyer a stronger basis for a more optimistic growth story than in-place rent increases alone can support under the new 4% ceiling. Sellers who can show that turnover, rather than relying purely on in-place increases, have a materially stronger negotiating position than sellers whose only growth story is the now-lower 4% ceiling, a gap that on the worked example above ran to $75,802 in year-five NOI alone.

Marcus & Millichap's Q2 2026 Los Angeles multifamily market report found that buyer underwriting assumptions for RSO-covered product have diverged measurably from those applied to AB 1482 buildings in comparable submarkets, with institutional buyers applying a 25-to-50-basis-point premium cap rate to RSO deals where in-place rents sit more than 20 percent below market, reflecting the slower projected growth path under the 4% ceiling (Marcus & Millichap, Q2 2026). That premium cap rate, applied to the same current NOI, directly reduces the offer price a buyer can submit while still hitting their target return, separate from any shift in the underlying market-wide cap rate.

How RSO Compares to AB 1482 for Building Value in Los Angeles

Buildings in Los Angeles that fall outside RSO coverage, generally those built after October 1, 1978 or otherwise exempt, are governed by AB 1482 instead. AB 1482's cap is calculated as 5% plus local CPI, up to a hard ceiling of 10%, which remains materially higher than the RSO's new 4% maximum. This gap, which was narrower under the old 8% RSO ceiling, is now wide enough to create a real divergence in how buyers value the two building types.

Running the same illustrative math from the worked example above, but modeling an AB 1482 building at a growth ceiling closer to 8 to 10% instead of the RSO's 4%, produces a meaningfully higher projected year-five NOI and, by extension, a meaningfully higher terminal value at the same illustrative cap rate. This is not a statement that AB 1482 buildings are automatically better investments in every respect. RSO buildings can have advantages elsewhere, including established tenant bases and, in some cases, more stable occupancy. But on the specific dimension of projected in-place rent growth, AB 1482 buildings now have a clear structural advantage that did not exist as sharply before the RSO ceiling dropped from 8% to 4%.

Buyers who are indifferent between comparable RSO and non-RSO opportunities in the same submarket are increasingly likely to lean toward the AB 1482 asset, all else being equal, simply because the growth ceiling supports a more favorable pro forma. Sellers of RSO buildings competing for buyer attention against nearby AB 1482 listings should understand this dynamic when setting price expectations and structuring their marketing story around decontrol and turnover rather than in-place growth alone, since the ceiling gap itself, 4% versus a 10% maximum, is the entire source of the divergence.

CBRE's Q1 2026 Los Angeles multifamily investment report tracked increased buyer demand for AB 1482 product in the $3M-to-$10M mid-market segment, where RSO and AB 1482 buildings frequently compete for the same buyer pool, as underwriting teams incorporated the narrowed RSO ceiling into their return models at the start of the year (CBRE, Q1 2026). JLL's Q1 2026 Southern California multifamily update noted that the RSO ceiling change has accelerated a preference shift already forming as interest rate pressures compressed returns, with RSO-covered buildings requiring either a lower asking price or a more compelling decontrol narrative to attract competitive offer activity comparable to AB 1482 listings in the same submarket (JLL, Q1 2026).

Which Buildings Feel This the Most

Not every RSO building is affected equally by the new formula. The buildings most exposed are those with rents well below market, low historical turnover, and an owner or prior owner who relied heavily on in-place rent increases rather than unit turnover to close the gap to market rent. For a building like this, the old 8% ceiling represented a real, meaningful path to closing the gap over a reasonable hold period. Under the new 4% ceiling, that same path is significantly slower, and a buyer's model will reflect that directly.

Buildings least affected are those where in-place rents already sit close to market rate. If there is limited room to grow rent regardless of what the RSO ceiling allows, the formula change is close to irrelevant to that specific building's value, because the ceiling was never the binding constraint in the first place. For these buildings, the value story is driven far more by occupancy, condition, expense ratios, and submarket demand than by the RSO formula.

Buildings with strong historical turnover sit in between. A building where units regularly turn over, allowing the owner to reset rent to market through vacancy decontrol, is less dependent on in-place growth to reach market rent than a building with long-tenured residents. For these buildings, documenting that turnover history clearly for a buyer is the single most effective way to offset the impact of the lower in-place growth ceiling on the overall value story.

Submarket matters here too, though not in the way owners sometimes expect. The RSO formula applies uniformly across every covered building in the City of Los Angeles, so a pre-1978 building in Koreatown and a pre-1978 building in Highland Park operate under the identical 4% ceiling. What differs by submarket is the size of the gap between in-place rent and market rent. In submarkets where market rent has climbed faster than in-place rents over the past decade, such as pockets of Echo Park and Silver Lake, the compression effect described above tends to be more pronounced, because there is more distance left to close and the new ceiling slows that closing process more noticeably. In submarkets where rent growth has been flatter, the gap between the old and new formula matters less in practice, since there was less room to grow either way, regardless of whether the ceiling sits at 4% or the old 8%.

CoStar's Q2 2026 Los Angeles market analytics tracked approximate cap rate and per-unit value ranges across LA submarket tiers, providing context for how building location affects the degree to which the new RSO ceiling compresses a buyer's projected return (CoStar, Q2 2026). The table below summarizes approximate market ranges by submarket tier as of mid-2026. These figures are market-range approximations derived from CoStar and Marcus & Millichap Q2 2026 data and are not a quote or appraisal for any specific property.

Is It Still Worth Holding Your Building

For Los Angeles apartment owners, this is the question underneath all of the math above, and it does not have a single answer that applies to every owner. A building with rents already close to market, healthy occupancy, and a reasonable expense ratio may perform acceptably under the new formula, particularly if the owner is not counting on aggressive in-place growth to hit their target return. For that kind of asset, holding through the transition may still make sense.

A building with rents well below market, limited turnover, and an owner whose original investment thesis depended on closing that gap primarily through in-place increases is in a different position. The new formula slows that thesis down considerably, and the owner has to weigh whether the remaining upside still justifies the hold period, the debt service, and the opportunity cost of the equity tied up in the asset, versus selling now, redeploying into an AB 1482 asset or a different market, or executing a 1031 exchange into a property type with a more favorable growth ceiling.

There is no generic answer here, and any broker or advisor who gives you one without looking at your actual rent roll, tenancy lengths, and turnover history is not giving you complete guidance. This decision should be made against a current, written valuation built on the same NOI-over-cap-rate math shown above, where a $75,802 swing in year-five NOI alone produced a seven-figure difference in terminal value.

What to Do Before You List or Refinance

Start with an updated rent roll for your Los Angeles apartment building that shows exactly where each unit sits relative to market rent, plus a clean turnover history for the trailing three to five years. This is the raw material any buyer or lender will ask for, and having it ready before you list, rather than assembling it under pressure once an offer comes in, puts you in a stronger position.

Next, get a written valuation that explicitly accounts for the new RSO formula's effect on projected NOI growth, rather than one built on last year's 8% ceiling assumptions. If your broker's valuation does not walk through the mechanism the way this article does, ask them to show the math, not just the bottom-line number.

Finally, decide what story you want to tell a buyer about your building's growth path. If the story is primarily in-place rent growth, the new 4% ceiling is your constraint and needs to be reflected honestly in your pricing expectations. If the story includes meaningful decontrol upside through documented turnover, make sure that history is presented clearly, since it is the strongest offset available to a ceiling that has dropped from 8% to 4%.

What the New RSO Formula Means for Value at a Glance

Here is how these dynamics typically play out across a Los Angeles apartment building portfolio, depending on where your rent roll sits relative to market.

Frequently Asked Questions

How do the 2026 RSO changes affect my apartment building's value?

The new RSO formula, effective July 1, 2026, caps allowable rent increases at 90% of CPI with a 4% maximum, down from the prior 8% ceiling. Because value equals NOI divided by cap rate, a lower ceiling on rent growth slows projected NOI growth over a hold period, which compresses the terminal value a buyer will underwrite, even if the current-year cap rate does not move. Buildings with rents already near market feel this less than buildings with significant room to grow rents in place.

Does a lower rent cap always mean my building is worth less?

Not automatically, but it changes the growth assumption a buyer builds into their offer. A building's value is driven by current NOI, projected NOI growth, and the cap rate a buyer applies to that income stream. If your rents are already close to market, the RSO ceiling matters less because there was limited room to grow in-place rent anyway. If your rents sit well below market, the new 4% ceiling meaningfully slows how fast a buyer can close that gap through in-place increases alone, which shows up as a lower offer or a more conservative growth assumption in their model.

What is the formula for calculating my apartment building's value?

The standard income approach is Value equals Net Operating Income divided by Cap Rate. NOI is gross rental income minus operating expenses, before debt service. A lower cap rate produces a higher value for the same NOI, and a higher NOI produces a higher value for the same cap rate. When rent growth slows due to a lower RSO ceiling, projected future NOI is lower than it would have been under the old formula, which compresses the value a buyer is willing to pay today for that future income stream.

How much did the RSO rent increase cap change in 2026?

Effective July 1, 2026, the RSO formula changed from 100% of CPI with an 8% maximum and 3% minimum floor to 90% of CPI with a 4% maximum and 1% minimum floor. The formula also eliminated the master-meter utility add-on and the 10% additional-dependent add-on that owners could previously apply on top of the base increase (LAHD RSO Overview; AAGLA member alert; Los Angeles City Council legislative file adopting the ordinance, enacted January 24, 2026).

Will buyers pay less for my RSO building because of the new formula?

Buyers underwriting RSO deals are now modeling slower rent growth into their pro forma, which affects what they can offer while still hitting their target return. This typically shows up as either a lower offer price at the same cap rate, or the same offer price built on a more conservative NOI growth assumption. Sellers should expect this to appear in offers themselves, not just in general market commentary, and should have their own updated net proceeds and value analysis before setting a list price.

Are non-RSO buildings worth more than RSO buildings now?

Non-RSO buildings, generally those built after October 1, 1978, fall under AB 1482 instead of the RSO, and AB 1482's cap of 5% plus local CPI, up to a 10% ceiling, remains materially higher than the RSO's new 4% maximum. Buyers modeling faster potential rent growth on AB 1482 buildings may show more interest in that stock relative to comparable RSO buildings, which is a value-shift dynamic worth understanding, not just a compliance difference between the two frameworks.

Is it still worth holding my rent-controlled apartment building?

It depends on your specific rent roll, how far below market your in-place rents sit, your remaining hold horizon, and what alternative uses of the equity look like. A building with rents already close to market and steady occupancy may still perform reasonably well under the new formula, since decontrol on turnover remains available. A building with rents well below market and low turnover may see a meaningfully slower path to closing that gap. Modeling both scenarios against a current valuation is the only way to answer this for your specific address rather than the market in general.

How does cap rate interact with the new RSO formula?

The cap rate itself has not changed because of the RSO formula update; cap rates move based on interest rates, buyer demand, and perceived risk in the broader market. What has changed is the NOI growth assumption buyers plug into their model before applying that cap rate. Two buildings with an identical current cap rate can have very different projected values five years out if one is RSO-covered under the new 4% ceiling and the other is an AB 1482 building capped near 8 to 10%.

What should I do before listing my apartment building under the new RSO rules?

Get a current written valuation that reflects the new RSO formula's impact on projected NOI growth for your specific rent roll, not a valuation based on last year's 8% ceiling assumptions. Review how far your in-place rents sit below market, your tenancy lengths and turnover history, and whether vacancy decontrol has been realistically factored into the growth story. A valuation built on outdated growth assumptions will not hold up once a buyer's underwriting team runs their own numbers.

Does the new RSO formula affect refinancing an existing apartment building loan?

It can. Lenders sizing a refinance loan look at projected NOI growth as part of their underwriting, similar to how a buyer would. A slower projected growth trajectory under the new 4% RSO ceiling can affect the loan amount a lender is willing to size against future income, particularly on cash-out refinances that rely partly on projected rent growth to support the requested loan amount. Owners considering a refinance should ask their lender directly how the updated RSO formula factors into their underwriting model.

Do I need a new appraisal because of the RSO formula change?

Not automatically, but if your most recent appraisal or broker opinion of value was prepared before the new formula's July 1, 2026 effective date, its underlying growth assumptions are likely outdated. This matters most if you are actively marketing the building, negotiating a refinance, or making a hold-versus-sell decision based on that older figure. An updated valuation that explicitly reflects the 4% ceiling gives you a more accurate current picture than relying on a pre-2026 number.

Where can I get a free valuation that accounts for the 2026 RSO changes?

Kingside Investment Group has closed 169 multifamily transactions totaling $336.5M and 1,700+ units across LA County and provides a free property valuation that accounts for the new RSO formula's effect on projected NOI growth. Request one at kingsideinvestmentgroup.com/our-services/what-is-my-property-worth or call Andres Diaz directly at (323) 376-2469.

Andres Diaz, Managing Director, Multifamily Investments

CA DRE #01956479 · Kingside Investment Group

Andres Diaz has closed 169 multifamily transactions totaling $336.5M and 1,700+ units across LA County, guiding sellers through valuation shifts driven by changes in rent control law, cap rate movement, and value-add repositioning. He models the new RSO formula's NOI impact into every property valuation before a building goes to market.

(323) 376-2469 | Andres.Diaz@kw.com | View Full Profile | Verify License

Related reading: How Much Can I Raise Rent in Los Angeles in 2026? for the full compliance breakdown of the RSO and AB 1482 formulas referenced in this article. Also see What Is the AB 1482 Rent Increase Limit for 2026 in California? and Los Angeles Apartment Building Cap Rates for 2025-2026 for the market-wide cap rate data referenced in the worked example above.