If you live near the old Edison offices on Walnut Grove Avenue, the proposal would replace the vacant buildings with 191 townhomes. It would also require land use changes, demolition and a construction period analyzed at about 34 months. Approval has not been confirmed.
This is general information and not legal advice.
As of October 21, 2026, the Rosemead Planning Commission had a public hearing on this project scheduled for September 23, 2026. Insider could not confirm the outcome from the City’s posted records, so treat the project as proposed.
What is proposed at 1515 Walnut Grove?
The applicant, 1515 Walnut Grove, LP, proposes 191 townhomes in 27 buildings on about 9.28 acres at 1515 Walnut Grove Avenue.
Urbanize LA reported on September 8, 2026 on the plan for 191 homes at 1515 Walnut Grove Avenue.
The plan divides them into 83 tandem townhomes in 13 buildings and 108 row townhomes in 14 buildings. Residential floor area would total about 238,616 square feet, excluding garages.
Each unit would have a two-car garage, giving the development 382 garage spaces, with electric vehicle capability. Another 104 spaces would serve guests; the draft study says the code requires 96. The proposal also includes about 126,720 square feet of open space.
Access would be from Walnut Grove Avenue. The community would be gated, with key fobs and vehicle transponders for residents and a dial-up kiosk for visitors.
What land use changes does it need?
The proposal needs a General Plan Amendment and Zone Change, along with subdivision and development entitlements.
The General Plan designation would change from Office/Light Industrial to High Density Residential. Zoning would change from Medium Commercial, or C-3, with a Design Overlay, or D-O, to Planned Development, or P-D. The draft study says High Density Residential allows attached housing, including condominiums and townhouses, with a maximum permitted density of 30 units per acre.
For tracking purposes, the hearing notice lists General Plan Amendment 24-01, Zone Change 24-01, Planned Development 24-01 and Tentative Tract Map No. 84626.
Those are requests. Their appearance in a notice does not establish that they were granted.
Where does the approval process stand?
The City scheduled a Planning Commission hearing, and Insider could not confirm its outcome.
The notice scheduled the hearing for September 23, 2026, at 7:00 PM at Rosemead City Hall, 8838 Valley Boulevard. The environmental review period ran from August 27 through September 16, 2026, a period of 20 calendar days. Both dates have passed.
The City of Rosemead concluded that the project would have a significant impact unless mitigated and prepared a Mitigated Negative Declaration. That conclusion makes the proposed mitigation measures part of what you should read. It does not establish project approval.
For a nearby owner weighing a sale, keep the proposal’s status separate from its design details. A detailed plan can still be a proposed plan.
Say an owner of a home west of the site plans to list it and opens the townhome plans while preparing disclosures. The drawings show buildings, garages and landscaping, but the owner still needs to check the City’s current meeting records for an approval outcome. With that outcome unconfirmed, the owner would describe the development as proposed. The construction study’s early dates would remain an analysis scenario, rather than a confirmed schedule to pass along to a buyer.
What is on the site today?
The draft study describes two vacant buildings built in 1982 and formerly operated by Southern California Edison, plus a surface parking lot with about 717 spaces.
The office building contains 249,701 square feet, and the detached central plant contains 18,314 square feet. Both would be demolished. The proposed residential floor area, excluding garages, would be about 29,399 square feet less than the existing buildings.
The surrounding uses help locate the change: offices and parking lie north, University of the West lies south, and single-family homes in unincorporated Los Angeles County lie west. Across Walnut Grove Avenue to the east is Whittier Narrows Golf Course, also in unincorporated county territory.
What would construction look like for neighbors?
The draft study analyzes construction in one phase lasting about 34 months, with demolition, imported material and work along Walnut Grove Avenue.
Its conservative analysis scenario begins as early as October 2026 and ends as early as August 2029. Those dates are not a confirmed construction schedule.
Under Rosemead Municipal Code Chapter 8.36, construction is prohibited between 8 p.m. and 7 a.m. Monday through Saturday, and on Sundays or federal holidays. The study anticipates no nighttime construction.
About 7,500 cubic yards of material would be imported. Recycled concrete and asphalt would stay onsite. Right-of-way work would include parkway and sidewalk improvements and roadway repair through grinding and overlay.
If you live beside the property, these are concrete details to check against later project records: the work period, permitted hours and frontage work.
What did the fault study find?
The site is within a designated Alquist-Priolo Earthquake Fault Zone, and the site-specific investigation reached a different conclusion from earlier fault mapping.
The draft Initial Study/Mitigated Negative Declaration says Holocene-active faults had previously been mapped across the site. It reports that a 2024 Fault Rupture Hazard Investigation concluded the previously inferred faults are either non-existent or not Holocene-active.
There is an unresolved limit. Utility conflicts prevented investigation of the northeastern and southwestern corners. Those areas have not been cleared of faults and cannot be built on unless additional studies are conducted. The proposal places landscaping and park areas there, with no buildings.
Mitigation measure GEO-1 requires an engineering geologist to observe and document excavations and recommend structural setbacks if active or age-undetermined faults are found during grading.
What should a future buyer know?
A future buyer should treat this as a proposed development, not a built community with homes available to buy.
The documents do not establish prices, dues or whether the units would be offered for sale or rent. They do describe a gated development and its planned parking and access arrangements.
The state-mapped earthquake fault zone is also a matter for natural hazard disclosures. Ask for the geotechnical and fault reports, including the limits on investigation at the two corners. The guide to natural hazard disclosure reports can help you read that paperwork.
If you are selling a nearby home, use the California seller disclosure guide as a companion when preparing your disclosures. For questions about a future purchase’s stage and timing, the new construction home guide offers related reading; the Rosemead documents remain the source for this proposal.
How can you follow the proposal and comment?
Start with the City’s public notices and current meeting records to establish the latest status and any next opportunity to comment.
The public notices page is where the City posts these documents. Search using the address and case numbers, and watch City Council agendas if the item goes there.
The hearing notice says it was mailed to owners of real property shown on the latest equalized assessment roll within 300 feet of the site, which can include homes to the west in unincorporated county territory. It also says it was posted onsite and in six public locations.
The notice also warns that a later court challenge may be limited to issues raised at the hearing or in written correspondence delivered at or before it. Because that hearing date has passed, check the current record before relying on the old notice’s comment instructions.
The short version
The proposal would replace the former Edison offices with 191 townhomes, but its approval outcome remains unconfirmed.
For nearby owners, the useful details are the proposed land use changes, construction analysis and notice process. For a future buyer, the fault reports and their investigation limits deserve a careful read.
If you are considering selling your Rosemead home, start with the home value tool.
Common questions
Has Rosemead approved the 1515 Walnut Grove townhomes?
Insider could not confirm the hearing outcome from the City's posted records as of October 21, 2026. Treat the project as proposed.
How many townhomes are proposed?
The application proposes 191 townhomes in 27 buildings on about 9.28 acres at 1515 Walnut Grove Avenue.
How long would construction take?
The draft environmental study analyzes one phase lasting about 34 months. Its early dates are an analysis scenario, not a confirmed construction schedule.
What did the fault investigation find?
The site is within a designated Alquist-Priolo Earthquake Fault Zone. A site-specific investigation concluded that faults previously inferred to cross the site are either non-existent or not Holocene-active. Two corners remain uncleared because utility conflicts prevented investigation.
