A vacant office campus on Potrero Grande Drive in Monterey Park has changed hands for $25 million, and the new owner is not interested in tenants — it wants to build homes. The Olson Company has finalized plans to convert the 8-acre site into 159 condominium units, marking the latest office-to-residential flip reshaping this stretch of the San Gabriel Valley.
The complex includes a three-story, 91,360-square-foot building at 601 Potrero Grande Drive and a second office building at 2100 Saturn Street totaling 28,840 square feet, according to The Real Deal. Together, the now-vacant medical office buildings span 120,200 square feet and sit alongside 508 surface parking spaces. Seal Beach-based Olson, which has built more than 11,000 homes across 100 California cities, is officially making its office-to-condominium conversion plans real after buying the property from a seller represented by Jeff Bramson, Will Poulsen and Andrew Harper. Ryan Campbell represented Olson in the deal.
The $25 million price tag represents a steep jump from what the property last sold for. Blue Shield of California, which previously occupied the campus, sold it to BH Properties for $15 million in 2022. Per The Registry Southern California Real Estate News, that earlier deal — reported at $24.85 million elsewhere and pegged at roughly $206.75 per square foot — works out to a 65.7 percent premium, or roughly $9.85 million more than BH Properties' $124.80-per-square-foot purchase four years earlier. The jump illustrates how residential conversion potential, not office lease income, is now driving land values in this corner of the San Gabriel Valley even as commercial office demand struggles regionally.
From Blue Shield Headquarters to Vacant Lot
Blue Shield of California sold the campus under a sale-leaseback arrangement in May 2022 that let its Promise Health Plan headquarters keep operating there through July 2023, according to The Real Deal's earlier reporting on the original sale. That timeline explains why the buildings sat vacant by the time Olson entered the picture, giving BH Properties a distressed asset with a built-in tenant exit before eventually selling to Olson.
The property falls under Monterey Park's Saturn Park (S-P) zoning designation, part of the city's business park overlay district, which required density bonus incentives for Olson to exceed standard residential density limits, per the same Registry account. That regulatory maneuvering cleared the way for the Monterey Park City Council to approve Site Development Plan No. 25-131, Density Bonus DRB-26-067 and Vesting Tentative Map No. 84935 on June 17, 2026, according to The Common News. As a condition of that approval, the city council required any recognized environmental conditions flagged in the property's Phase I environmental site assessment to be fully remediated before a certificate of occupancy could be issued.
What's Being Built: Potrero Grande & Atlas
Officially named Potrero Grande & Atlas, the gated townhome development will offer floor plans ranging from 1,100 to 2,000 square feet with attached two-car garages, a linear park, walking paths and a central open space cabana with barbecue facilities, according to Multi-Housing News. Market-rate units will range between two and four bedrooms, while the plan also calls for eight live-work units built above ground-floor retail or office space. The Olson Company presented the project to the Monterey Park City Council and hosted a public open house on April 20, 2026, at the George Elder Park Community Room to gather resident feedback ahead of the vote, according to the City of Monterey Park.
Eight of the 159 units will be designated affordable at the very low-income level, reserved for households earning 50 percent or less of Los Angeles County's Area Median Income under state density bonus provisions, per Multi-Housing News. Those affordable units span roughly 1,280 square feet across three bedrooms. Planned amenities also include landscaped open space with picnic tables and lounge areas, plus a community building that doubles as coworking space for residents. KTGY is designing the project, with delivery targeted for 2028.
Part of a Wider Office-to-Housing Wave
Monterey Park is not converting just one office park. The city approved a proposal in April 2026 for Deerfield Center, a five-story, 369-unit mixed-use development at Atlantic Boulevard and Garvey Avenue, part of what LA YIMBY describes as a broader push to replace aging commercial corridors with multifamily housing to meet state mandates. Hoodline previously covered that 369-unit proposal when it first surfaced.
The pivot toward housing is notable given that San Gabriel Valley's office market isn't as troubled as the region overall. The submarket held a total office vacancy rate of 9.2 percent in the first quarter of 2026, well below Los Angeles County's overall office vacancy rate of 15.9 percent, according to Innovation Properties Group. Developers appear to be chasing residential land values rather than waiting out office demand even in submarkets with comparatively strong commercial retention.
Olson's Monterey Park purchase is one of several moves the developer has made recently across Los Angeles County, according to The Real Deal. The company is also building a similar project elsewhere in the county and developing a KTGY-designed, 80-unit housing complex in San Gabriel. In April 2026, Olson paid $8.1 million for a 1.9-acre church-owned parking lot in Yorba Linda, where it plans to build 40 affordable townhomes, continuing the company's focus on affordable infill projects across Southern California.
For now, questions remain about how quickly the Phase I environmental remediation can be completed and whether nearby infrastructure can absorb the added traffic once construction wraps around 2028, concerns noted in coverage from both Multi-Housing News and The Common News. Until those pieces fall into place, the Potrero Grande and Saturn Street buildings will sit empty, waiting for the transformation from medical offices to condominiums to begin.
