How United Build Partners helps Santa Monica homeowners
We're not a construction company. United Build Partners is an ADU advisory and contractor-matching service: we start with a free review of your property and goals, help you understand what's realistic for your lot under Santa Monica's rules, and — when it's a good fit — connect you with up to three contractors in our network suited to your project type and neighborhood. From there, you compare proposals and decide who to work with; the licensed contractor you choose handles the actual design and construction.
ADU rules and permitting in Santa Monica
Every ADU in California starts from the same statewide floor: ministerial (by-right) approval, at least 16–18 feet of height, 4-foot side and rear setbacks, and no owner-occupancy requirement for a standard ADU. Santa Monica layers its own standards and a preapproved-plan program on top. Here's what stands out locally.
What's specific to Santa Monica
- Preapproved ADU Program under AB 1332. Santa Monica runs a preapproved Standard ADU Plan program: a plan vendor gets a design approved without site-specific details, then a homeowner selects it and goes through an expedited building-permit review. Two honest caveats — the preapproved plans are for detached ADUs only, and the city's approved-vendor list currently shows none at this time, so confirm what's actually available before counting on the catalog.
- Setbacks are modest but specific. City standards generally keep an ADU out of the front setback, require at least 4 feet from side and rear property lines, and require a detached ADU to sit at least 6 feet from the main house, measured wall to wall. That 6-foot separation is a Santa Monica detail worth designing around from the first sketch on a small lot.
- Ministerial approval — no hearings. ADUs are processed ministerially: no design review and no public hearing, just a building permit. That removes the discretionary-approval risk that stalls projects in cities with design boards.
- Coastal Zone parcels carry an extra step. If your property sits in the Coastal Zone, a Coastal Development Permit or Waiver may also be required through the California Coastal Commission — a real added step for beach-adjacent Santa Monica lots. Whether it applies is parcel-specific, so confirm your coastal status with Planning early.
- Impact fees only above 750 square feet. Consistent with state law, smaller ADUs avoid development impact fees; the city notes that ADUs larger than 750 square feet may be subject to Public Works impact fees. Keeping a unit at or under 750 sq ft is one concrete lever on the budget.
- Preapproved plans expire with the code cycle. The city's standard ADU plans are valid only within the same triennial California Building Standards Code cycle in which they were approved — so any preapproved plan has a shelf life tied to code updates.
Property and lot considerations
Santa Monica lots are famously compact and valuable, and many sit within or near the Coastal Zone. On a small lot, the 6-foot separation from the main house and the 4-foot side and rear setbacks are usually the binding constraints — which is why siting and unit shape matter here more than chasing maximum square footage. A free property review is the fastest way to see what your specific parcel, and its coastal status, will realistically support; our size & setback calculator is a good first check.
Common ADU types for Santa Monica homeowners
Detached new-construction ADUs, garage conversions, and junior ADUs (JADUs) inside the main house are all common in Santa Monica. The city's preapproved-plan program is limited to detached ADUs, so if a standard plan appeals to you, a detached unit is the path; conversions and JADUs follow the regular permit route. Our which-ADU quiz helps narrow the choice to your lot and goals.
Cost factors in Santa Monica
Santa Monica's high land values don't directly change construction costs, but tight lots, limited staging room, and coastal-adjacent conditions can raise site and access costs. The 750-square-foot impact-fee threshold is a real budget lever — a unit at or under it avoids Public Works impact fees. Our cost guide and soft-costs guide frame the full budget beyond the build itself.
Financing your Santa Monica ADU
Most homeowners fund ADU construction through a HELOC, cash-out refinance, a construction loan, or some combination — see our ADU financing overview and loan payment calculator for how each works. Financing options aren't generally city-specific, but a lender may consider your neighborhood and local rents when evaluating projected rental income as qualifying income.
How our process works
Frequently asked questions
State law (AB 976) generally bars cities from imposing an owner-occupancy requirement on a standard ADU, and Santa Monica processes ADUs ministerially. Because cities vary in how they've updated their codes, confirm the current treatment with Santa Monica Planning before relying on it — and note that JADUs are treated differently from standard ADUs under state law.
The city's standards call for no ADU in the front setback, at least 4 feet from side and rear property lines, and a detached ADU at least 6 feet from the main house measured wall to wall. That 6-foot separation is a Santa Monica-specific detail — design for it early, especially on a small lot.
If your parcel is in the Coastal Zone, a Coastal Development Permit or Waiver may be required through the California Coastal Commission in addition to your city building permit. Whether it applies depends on your exact location, so confirm your parcel's coastal status with Santa Monica Planning early — it can affect your timeline.