Selling a rental building with three or more units in San Francisco means dealing with the city’s Community Opportunity to Purchase Act before you ever get to close escrow with an ordinary buyer — a step that catches a lot of small landlords off guard because it has nothing to do with tenant protections most people have already heard about.

COPA, codified in Chapter 41B of the San Francisco Administrative Code, gives city-certified nonprofit organizations a shot at buying the building before it goes to the open market, and it requires a signed compliance declaration after every covered sale whether or not a nonprofit ends up involved.

Here’s what it actually requires, who it applies to, and how it fits alongside San Francisco’s other point-of-sale rules — covered elsewhere in the 3R report San Francisco requires before you can sell a home and San Francisco’s tiered transfer tax.

Table of Contents

What Triggers COPA

COPA applies to the sale of any residential building with three or more units, and separately to vacant land zoned or sized in a way that could be developed into three or more residential units.

It doesn’t matter whether the units are currently rented, vacant, or owner-occupied alongside tenant units — the trigger is the building’s unit count, not its current occupancy.

A single-family home or a duplex falls outside COPA entirely; a small triplex that a lot of owners think of as a modest rental property is squarely covered.

This threshold catches a meaningful slice of San Francisco’s rental housing stock, since three- and four-unit buildings are extremely common throughout the city’s older residential neighborhoods, and it’s a different and lower bar than some other San Francisco housing ordinances use, which is exactly why it surprises owners who assume a program aimed at “affordable housing preservation” must only be about larger apartment complexes.

The Nonprofit’s Right of First Offer and Right of First Refusal

The core of COPA is giving MOHCD-certified qualified nonprofit organizations the right of first offer, and in some circumstances the right of first refusal, to purchase a covered property ahead of a sale to anyone else.

In practical terms, this means a seller generally has to give qualified nonprofits notice of an intent to sell and an opportunity to make an offer before — or, depending on the specific circumstances and timing, instead of — accepting a competing offer from an ordinary buyer.

The city’s Mayor’s Office of Housing and Community Development administers the nonprofit certification process on a rolling, year-round basis, so the pool of eligible nonprofit buyers isn’t fixed; it’s whoever currently holds MOHCD certification at the time a given property goes to market.

The ordinance includes a carve-out tied to its original effective date of September 3, 2019: a seller who already had a binding purchase agreement with a non-qualified buyer signed before that date generally didn’t have to comply with COPA for that specific transaction, though if that original agreement later fell through, the seller would have to comply with COPA before offering the property to anyone else.

That carve-out is now largely historical for new sales, since any transaction happening today is well past that original effective date, but it illustrates how the ordinance transitions existing deals into the new requirement rather than retroactively unwinding contracts that predated it.

The Tenant Notification Requirement

Separately from the nonprofit opportunity-to-purchase mechanism, COPA requires sellers to notify existing tenants of the intent to sell a covered building, using MOHCD’s own COPA Tenant Notification Form.

This notice exists so that tenants in the building know a sale is coming and understand the role qualified nonprofits may play in the process — it’s a disclosure obligation to the people already living there, distinct from the separate notice process aimed at nonprofit buyers.

Skipping this step, or treating it as optional because the seller already has a buyer lined up, is a compliance gap that shows up later when MOHCD or a prospective nonprofit purchaser reviews the file.

The Seller’s Declaration After Closing

Every seller of a COPA-covered property, regardless of whether a nonprofit ultimately bought it or an ordinary market buyer did, must submit a signed declaration to MOHCD within 15 days after the sale closes, stating under penalty of perjury that the sale substantially complied with Chapter 41B’s requirements.

This isn’t a formality that only matters if a nonprofit was involved — it’s a universal post-closing obligation for every covered transaction, and MOHCD publishes the addresses of properties for which declarations have been submitted, creating a public record of compliance (or its absence) tied to specific addresses.

Missing this 15-day window doesn’t just create paperwork exposure.

Qualified nonprofits have the ability to bring a civil action against a seller who didn’t comply with COPA’s requirements, and an unfiled or late declaration is exactly the kind of gap that invites scrutiny of whether the underlying sale process followed the ordinance at all.

Sellers working with a title company or real estate attorney familiar with San Francisco transactions typically have this declaration built into the standard closing checklist, but anyone selling without that kind of specialized local guidance should specifically confirm who is responsible for filing it and that it actually gets filed on time.

Why San Francisco Passed COPA

COPA took effect September 3, 2019, as part of a broader set of city policies aimed at preserving existing rental housing as permanently affordable rather than losing it to speculative resale and subsequent rent increases or Ellis Act conversions.

The underlying concern driving the ordinance was that smaller multi-unit buildings — exactly the three-and-up unit count COPA targets — were disappearing from the city’s rent-controlled housing stock faster than new affordable units were being built, and that giving mission-driven nonprofits a structural advantage in the acquisition market was one lever the city could pull without directly regulating private sale prices.

Understanding that underlying purpose helps explain why the ordinance is structured the way it is: it doesn’t cap what a seller can charge or prevent a sale to a private buyer outright, it just inserts a qualified nonprofit’s opportunity to compete for the purchase ahead of, or alongside, the ordinary market process.

Who Actually Counts as a Qualified Nonprofit

Not every nonprofit organization in San Francisco can exercise COPA rights — MOHCD maintains the certification process specifically so that only organizations with the demonstrated capacity, mission alignment, and financial backing to actually close on an acquisition and then operate it as permanent affordable housing can participate.

Certification is an ongoing, rolling process rather than a one-time annual list, which means the specific roster of eligible nonprofits for a given property sale depends on who holds active certification at that moment.

A seller or their broker can’t simply assume the same handful of large, well-known nonprofit housing developers are always the only ones in play — smaller, neighborhood-specific nonprofits sometimes hold certification too, particularly for buildings in specific districts where a local organization has a particular interest or existing presence.

A Practical Checklist for Sellers of a Covered Building

Confirm the building’s actual unit count against COPA’s three-unit threshold before assuming it is or isn’t covered — don’t rely on how the property was marketed or how many units appear on the tax roll if there’s any ambiguity about legal versus actual unit count
Serve the required tenant notification using MOHCD’s COPA Tenant Notification Form before marketing the property, not after a buyer is already identified
Confirm with MOHCD or a knowledgeable local real estate attorney which qualified nonprofits currently hold active certification and need to receive notice of the opportunity to purchase
Build the nonprofit notice period into the overall marketing and escrow timeline from the outset, rather than treating it as an afterthought once a private offer is in hand
Calendar the 15-day post-closing deadline to file the seller’s declaration with MOHCD the moment escrow closes, so it doesn’t get lost in the general flurry of post-closing paperwork
Keep a record of exactly how and when nonprofit notice was given, since that documentation is what would support a seller’s position if a qualified nonprofit later claimed the opportunity-to-purchase process wasn’t properly followed
Ask the title company handling the sale whether it has handled COPA-covered transactions before — experience with the specific MOHCD forms and declaration process meaningfully reduces the odds of a step getting missed or filed incorrectly

What Happens When a Nonprofit Actually Buys

If a qualified nonprofit does exercise its right under COPA and purchases the building, the property comes with permanent affordability restrictions attached.

Average rents and utility costs for residential tenants have to fall within a defined band relative to Area Median Income, and new tenants moving in after the purchase are subject to income limits tied to AMI as well.

A nonprofit holding a purchase agreement under COPA can only assign that agreement to another qualified nonprofit, not to an ordinary private buyer, which closes off a workaround some sellers might otherwise expect — once a qualified nonprofit is in contract, that contract stays within the pool of certified nonprofit purchasers if it needs to be assigned at all.

For a seller, this matters less as a direct obligation and more as a practical reality about who the eventual buyer might be and how that buyer’s financing and closing process may differ from a conventional private sale.

Nonprofit buyers operating under COPA frequently rely on dedicated public financing programs designed specifically for these acquisitions, which can mean a different, sometimes slower, closing timeline than a conventional all-cash or conventionally financed private buyer.

Vacant Land Is Covered Too, Not Just Existing Buildings

COPA’s reach extends beyond buildings that already have three or more units standing on them.

Vacant land that’s zoned, or otherwise sized and situated, in a way that would allow construction of three or more residential units is independently covered by the ordinance, even though there’s no existing rental housing on the site at all.

This surprises some sellers of undeveloped or underdeveloped lots who assume an ordinance clearly aimed at preserving existing rental housing has nothing to do with raw land.

The policy logic is consistent even if it isn’t obvious at first: the city’s interest is in who controls the future housing capacity of a site, not merely in protecting units that already exist, so a nonprofit’s opportunity to acquire land that could become affordable housing is treated the same way as its opportunity to acquire a building that already is housing.

Enforcement in Practice

Beyond the civil action a qualified nonprofit can bring against a non-compliant seller, COPA’s enforcement leans heavily on transparency rather than a dedicated city inspection or fine regime.

MOHCD’s public list of addresses with submitted seller declarations functions as a de facto compliance record that nonprofits, housing advocates, and future buyers’ attorneys can and do check.

A title company or buyer’s attorney reviewing a prior sale of a covered property as part of due diligence on a later transaction may specifically look for whether a COPA declaration was filed for that earlier sale, and a gap in that record can raise questions worth resolving before a subsequent deal proceeds, even years after the original sale.

This makes COPA compliance less like a one-time hurdle to clear and more like a permanent part of a covered property’s documented history.

How COPA Interacts With San Francisco’s Other Sale Requirements

COPA doesn’t replace or substitute for San Francisco’s other point-of-sale obligations — it stacks on top of them.

A seller of a three-unit building in San Francisco still needs the 3R Report documenting the property’s permit and building history, still faces San Francisco’s tiered transfer tax at closing, and still has to address any outstanding code violations or other disclosure obligations that apply to any residential sale in the city.

COPA adds the nonprofit notice and purchase-opportunity layer, plus the post-closing declaration, as additional steps specific to buildings of this size, rather than replacing anything else already required.

This layering is common across California’s larger cities — Oakland enacted its own community opportunity to purchase ordinance along similar lines, and cities up and down the state have been adding their own point-of-sale compliance regimes on top of standard disclosure law, a pattern covered elsewhere in how Oakland’s rent registry affects a seller of a rental property.

An owner with rental property in multiple California cities should expect each city’s specific rules to differ even when the underlying policy goal — preserving existing affordable or rent-controlled housing stock — is similar.

Why Timing Matters More Than It Seems

Because COPA’s nonprofit notice process has to happen before a sale to a non-qualified buyer is finalized, sellers who haven’t planned for it can find their closing timeline extended well beyond what a conventional three- or four-unit building sale would normally take.

A seller who lines up a private buyer without first understanding COPA’s requirements risks having to restart the process to give qualified nonprofits their statutory opportunity, which can cost weeks the seller didn’t expect to spend.

Building the nonprofit notice and tenant notification into the marketing timeline from the start, rather than treating COPA as paperwork to deal with once a private buyer is already under contract, is the difference between a routine delay and a deal that has to be unwound and restarted.

When a Direct Sale Still Makes Sense

None of COPA’s requirements prevent a straightforward private sale from closing — they just add specific notice and disclosure steps that have to happen in the right order.

For an owner who wants certainty about the timeline, working with a buyer and transaction team that already understands San Francisco’s COPA process, rather than discovering the ordinance’s requirements partway through escrow, avoids the most common source of delay.

Where a building genuinely needs significant repair work, or where the owner is managing several of these city-specific compliance regimes across multiple properties at once, a sale that can move efficiently once the COPA notice period has run its course is often the more practical path than a conventional listing that assumes none of this applies.

If you own a rental building in San Francisco and want help understanding how COPA and the city’s other sale requirements apply to your specific property, Cash Home Buyers CA can walk through the timeline with you, and you can see our Google Business Profile for examples of how we’ve handled similar multi-unit closings at our Google listing.

When you sell to us, we pay the standard closing costs, including the county and city transfer taxes, escrow and title.

What San Francisco’s COPA Ordinance Requires Before You Can Sell a Rental Building