Menlo Park · San Mateo County
ADU Design & Build in Menlo Park, California
From West Menlo to Felton Gables, we deliver ADUs that match the character of the street and the demands of the family inside.
Building ADUs in Menlo Park, California
SHAPE designs and builds accessory dwelling units for homeowners in Menlo Park, California, across West Menlo, Allied Arts, Felton Gables, Linfield Oaks, Sharon Heights, and the Willows.
Menlo Park sits between Stanford, Sand Hill Road, and Meta's Willow Village. That mix drives extraordinary rental demand for detached units and a strong appetite for multigenerational living on the older, larger lots west of El Camino.
We're a licensed California general contractor (CSLB #1158688) with an in-house architecture and modular construction team. That means one contract, one fixed price, and one team responsible from the first site walk through final inspection with the Menlo Park building department.
Menlo Park ADU Rules at a Glance
- Setbacks: California state law caps rear and side setbacks for new ADUs at 4 feet, and Menlo Park follows that standard.
- Height: Detached ADUs can be 16 feet tall, or 18 feet plus 2 feet for a roof pitch matching the main house within a half-mile walking distance of a major transit stop. Attached ADUs can reach 25 feet or the zoning limit, whichever is lower.
- Maximum size: Under the ordinance in effect since July 10, 2026, detached ADUs can be 850 sq ft with one bedroom or less and 1,000 sq ft with more, plus 100 sq ft if the ADU meets building-code accessibility requirements. A state-exempt detached ADU of up to 800 sq ft is always available.
- JADUs: Junior ADUs (up to 500 sq ft) are allowed inside the existing footprint of the primary home, in addition to a detached ADU on most single-family lots.
- Units allowed: Up to three on a single-family lot through the state-exempt route (one ADU inside the house, one junior ADU and one detached ADU), or one ADU under the local standards.
- Daylight plane: Applies to attached ADUs only, not to detached ADUs.
- Review: Staff approval with no public hearing. The city checks completeness within 15 business days and decides within 60 days of a complete application, or the ADU is deemed approved.
- Parking: Menlo Park's 2026 ADU ordinance requires no parking for ADUs.
Rules checked September 2026 against: Menlo Park ADU Ordinance No. 1129, Menlo Park ADU ordinance update, Menlo Park ADU permit process, HCD letter to Menlo Park, June 2026, Menlo Park heritage trees, San Mateo County Assessor, HCD ADU Handbook, California Energy Commission ADU guidance. City rules change often. We confirm the rules for your lot before design.
SHAPE handles the full permit package with the Menlo Park planning department, zoning verification, building plans, Title 24 energy, and every correction cycle, so you don't have to learn the code.
Our Process
- Site assessment. We walk your Menlo Park lot, confirm setbacks and utility locations, and give you a feasibility read and an all-in price the same week.
- Design. Our in-house architects design the ADU around your lot, your family, and your budget, with fixed pricing before you sign.
- Permits. We submit, respond to every planning and building comment, and drive the file to permit issuance with Menlo Park.
- Build. Modules are fabricated in our facility while site work, foundation, utilities, landscaping, runs in parallel. Set and finish happen on site.
What changed in Menlo Park's ADU rules in 2026
Menlo Park adopted a new ADU ordinance, No. 1129, on June 9, 2026, and it took effect July 10, 2026. It followed a December 2025 letter from the state housing department saying the city's 2020 rules were out of date, and the state found the new ordinance substantially compliant on June 15, 2026. The main changes for homeowners: no parking requirement, a 100 sq ft bonus for accessible designs, staff approval with no public hearing, and a path to legalize units built before January 31, 2023 without impact, connection or capacity fees. Older guides and handouts may still show the 2020 rules.
Site checks in Menlo Park
Trees, flood zones and the sewer district are the checks that most often change a Menlo Park plan.
- Heritage trees: native oaks from 10 inches in diameter and other trees from 15 inches, measured 54 inches above grade, are heritage trees. Work within 10 times the trunk diameter needs a tree protection plan, and removal permits cost $542 per tree for one to three trees.
- Flood zones: in any flood zone, the finished floor must sit 12 inches above base flood elevation.
- Sewer: most of Menlo Park is served by West Bay Sanitary District, which issues a $510 residential sewer permit and has moved to bill ADUs it was never told about. We register the ADU with the district from the start.
- Water: four different water providers serve Menlo Park. Menlo Park Municipal Water covers Sharon Heights and areas east of El Camino, so we confirm your provider early.
- Fire: Menlo Park Fire Protection District's 2025 ordinance says it is not responsible for any Very High fire hazard zone, and sprinklers are only needed in an ADU if the main house requires them.
Sources: Menlo Park heritage trees, Menlo Park 2026 Master Fee Schedule, Menlo Park flood and sea level rise checklist, West Bay Sanitary District permit fees, Menlo Park Municipal Water, Menlo Park Fire Ordinance 54-2025
Frequently asked
- How much does an ADU cost in Menlo Park?
- SHAPE's published prices start at $223,000 for Model 1, $263,000 for Model 2, and $343,000 for Model 2X on a typical lot. The final fixed quote in Menlo Park depends on size, finishes, utilities, access, and site conditions.
- How long do permits take in Menlo Park?
- California law requires ministerial ADU review within 60 days of a complete submittal. Real-world timelines in Menlo Park typically run 2–4 months including corrections. SHAPE manages every submittal and response with the Menlo Park planning department.
- Do I need to add parking for an ADU in Menlo Park?
- No. Menlo Park's ADU ordinance, in effect since July 10, 2026, requires no parking for ADUs, and no replacement parking is needed when a garage is converted or torn down.
- What size ADU can I build in Menlo Park?
- Menlo Park allows detached ADUs of 850 sq ft with one bedroom or less and 1,000 sq ft with more, plus 100 sq ft for an accessible design. On top of local rules, California state law guarantees at least 800 sq ft on most single-family lots regardless of local FAR limits.
- Can I rent out an ADU in Menlo Park?
- Yes. California state law allows long-term (30+ day) rentals of ADUs statewide. Short-term rentals are set by the city, Menlo Park, like most Bay Area jurisdictions, restricts or prohibits stays under 30 days.
- Can I legalize an older unpermitted unit in Menlo Park?
- Yes, if it was built before January 31, 2023. The city lets owners get a confidential third-party inspection first, waives impact, connection and capacity fees for these units with limited exceptions, and cannot deny the permit over building-code issues unless a health and safety fix is needed.
- Does Menlo Park have pre-approved ADU plans?
- Menlo Park runs a pre-approved ADU program, but its homeowner page currently says no plans are available. A custom design reviewed under the 2026 ordinance is the practical route today.
- What school fees apply to a Menlo Park ADU?
- School fees apply to new space over 500 sq ft. Sequoia Union High School District collects them for the local districts, and the Menlo Park City School District lists the rate at $5.38 per sq ft.
- What is the difference between an ADU and a junior ADU?
- A junior ADU is up to 500 square feet inside the main house, plus up to 150 square feet for an entrance. It needs its own efficiency kitchen but can share a bathroom with the house. An ADU can be attached or detached, with its own full kitchen and bathroom.
- How many bedrooms can a Menlo Park ADU have?
- State law does not let cities cap the number of bedrooms in an ADU. In Menlo Park, more than one bedroom raises the detached size limit from 850 to 1,000 square feet.
- Does a Menlo Park ADU need solar panels?
- A new detached ADU does. Under the 2025 California Energy Code it needs new solar panels, which can be added to an existing system elsewhere on the property. An attached ADU counts as an addition and does not need solar.
- Will an ADU raise my property taxes in Menlo Park?
- Only on the new building. The San Mateo County Assessor does not reassess your existing home. It adds the ADU's market value at completion to your current assessed value, with a partial assessment if the work is only partly done on January 1.
- Can I sell the ADU separately?
- Generally, no. Menlo Park has not adopted the state's optional condominium route under AB 1033, and its ordinance allows separate sale only in the narrow nonprofit case state law provides.
- Can I build the ADU and a new main house at the same time?
- Yes. State law lets the city approve both together, and the ADU is still reviewed without discretionary review. When the two are built together, utilities can treat the ADU as new residential use for connection fees.
- Is the California $40,000 ADU grant still available?
- No. CalHFA's ADU Grant paid up to $40,000 toward predevelopment costs, and CalHFA says its latest round was fully allocated in December 2023. CalHFA warns that anyone offering to get you one is running a scam.
- How long does PG&E take to connect an ADU?
- PG&E reported ADU electric hookups averaging about 300 days from request for projects finished by August 2025, and says its average for new service had dropped to 118 days by March 2026. We file with PG&E when the permit goes in so power is not the last thing we wait on.
Nearby cities we serve
Get a Free Site Assessment
Tell us about your Menlo Park lot and what you'd like to build. We'll walk the property, confirm feasibility, and come back with a fixed all-in price, no obligation.
