Building permits, zoning and land rules in Milpitas, California

At a glance

Building permits

Issued by City of Milpitas Building Safety¹

Zoning

City zoning applies inside Milpitas⁴

Septic systems

County Environmental Health permits and inspects OWTS³

RV living

No Milpitas-specific approval confirmed; ask Planning before occupancy⁵²

Tiny homes

Must fit an approved California building or vehicle classification and an allowed location⁶

ADUs

Allowed subject to Milpitas standards and a building permit⁷⁸

Owner-builder

State licensing exemption may apply, but building permits and inspections still apply⁹¹⁰

Who to call

Contact details are copied from each office’s official page and were checked against it on October 10, 2026.

Do you need a building permit in Milpitas, California?

Milpitas Building Safety issues building permits, checks building plans and provides inspections after permit issuance for construction inside the city.¹ California law also requires a permit before covered construction, alteration, repair, movement, improvement, removal, conversion or demolition of a building or structure.¹¹ ADUs and JADUs in Milpitas require a building permit, although an ADU that does not meet the cited zoning standards may also need Minor Site Development Permit approval.⁸ Contact Building Safety with the project address and scope before ordering plans because the necessary review depends on the work proposed.¹

Who issues building permits in Milpitas, and how do you reach them?

City of Milpitas Building Safety is the correct office for building permits, plan checks, design-guideline questions and building inspections inside city limits.¹ The office is at 455 E Calaveras Boulevard, Milpitas, CA 95035, and its phone number is 408-586-3240.¹ The Milpitas Planning Department handles zoning compliance, plan review and planning permits from the same address and can be reached at 408-586-3279.² Start with Planning when use, district standards or entitlement approval is uncertain, then work with Building Safety on the construction permit and required inspections.²¹

Does Milpitas have zoning, and what does it mean for ADUs and lot standards?

Milpitas has its own zoning ordinance, and residential development is subject to the standards of the applicable city zoning district.⁴ On a qualifying single-family lot, Milpitas allows up to one attached ADU, one detached ADU and one JADU, subject to development standards and building-permit requirements.⁷ The special R1 two-unit-project rule requires each primary dwelling on a resulting lot to contain at least 500 and no more than 800 square feet; that range is not a general size rule for every Milpitas home.¹² Ask Planning to identify the parcel's district and applicable setbacks, lot coverage and use standards before treating a listing or conceptual plan as buildable.²

How do septic permits work inside Milpitas?

Santa Clara County Environmental Health evaluates sites, reviews onsite wastewater treatment system designs, issues OWTS permits and conducts installation inspections where public sewer service is unavailable.³ A permit is required to construct, reconstruct or repair an individual septic system in Santa Clara County, and new development needs Environmental Health clearance before the building permit.¹³ Milpitas code separately requires a Health Officer permit for a cesspool, while Santa Clara County's countywide OWTS ordinance says cesspools are not authorized.¹⁴¹⁵ Treat the countywide prohibition as controlling and ask Environmental Health whether an individual Milpitas property may use an approved OWTS or must connect to sewer.¹⁵¹⁶

Can you live in an RV or tiny home in Milpitas?

California guidance says RVs are not intended as permanent dwellings and generally limits occupancy to mobilehome parks or special occupancy parks unless a local ordinance allows otherwise.⁵ We could not confirm a Milpitas rule allowing residential RV occupancy or temporary camping on a private lot, so ask the Milpitas Planning Department about the exact parcel and proposed duration before moving in.² A tiny home must qualify and be approved under an applicable California category, such as a code-built home, manufactured home, factory-built housing, RV or park trailer, and its location must also be approved.⁶ Milpitas does allow qualifying ADUs and JADUs, which offers a defined city pathway for a small accessory dwelling.⁷

Building a home in Milpitas: what are the steps?

1. Ask Milpitas Planning to confirm the zoning district, allowed residential use and any required planning approval for the parcel.²

1. Confirm sewer availability; if an OWTS may be needed, obtain Santa Clara County Environmental Health review before the building permit.¹³

1. Prepare the project plans and submit the building-permit application to Milpitas Building Safety.¹

1. If you act as an owner-builder, remember that California's contractor-license exemption does not remove building-permit or inspection duties.⁹¹⁰

1. Schedule and pass City of Milpitas building inspections as construction progresses.¹

What should you check before buying land in Milpitas?

Confirm that the property's Milpitas zoning allows the intended use and ask Planning for the district-specific development standards.⁴ If public sewer is unavailable, ask Santa Clara County Environmental Health about OWTS feasibility, soil testing, design review and setbacks before relying on a building concept.¹⁶ For a proposed well, California requires a permit from the applicable local environmental health agency or water district before construction, modification or destruction, but the responsible Milpitas-area office should be confirmed for the parcel.¹⁷ If access would encroach on a state highway right-of-way, a Caltrans encroachment permit is required.¹⁸

Watch-outs

• Do not apply Santa Clara County's unincorporated-area building, setback or RV rules to land inside Milpitas; the city administers its own zoning and building review.¹⁹¹
• A California owner-builder exemption concerns contractor licensing and does not waive building permits, code compliance or inspections.⁹²⁰
• We could not confirm a Milpitas-specific rule for private-lot RV occupancy, temporary camping or tiny-home siting, so obtain a parcel-specific answer from Milpitas Planning before purchase.²

Sources

1. City of Milpitas Building Safety (milpitas.gov)
2. City of Milpitas Planning Department (milpitas.gov)
3. Onsite Wastewater Treatment System (OWTS), quoted and re-checked
4. Milpitas Municipal Code, § B.4.030 Residential Zones Development Standards (Milpitas), quoted and re-checked
5. hcd.ca.gov (California statewide rule), quoted and re-checked
6. Information Bulletin 2016-01: Tiny Homes (California statewide rule), quoted and re-checked
7. Milpitas Municipal Code, § C.10.030 Accessory Dwelling Units and Junior Accessory Dwelling Units (Milpitas), quoted and re-checked
8. Milpitas Municipal Code, § C.10.030 Accessory Dwelling Units and Junior Accessory Dwelling Units (Milpitas), quoted and re-checked
9. California Business and Professions Code Section 7044 (California statewide rule), quoted and re-checked
10. Owner-Builder Responsibilities (California statewide rule), quoted and re-checked
11. Do I need a building permit for my project? (California statewide rule), quoted and re-checked
12. Milpitas Municipal Code, § B.4.040 Residential Zones Supplemental Standards (Milpitas), quoted and re-checked
13. Other approvals that may be needed for construction, quoted and re-checked
14. Milpitas Municipal Code, § V-3-2.04 Other Sanitary Facilities to be Provided (Milpitas), quoted and re-checked
15. Santa Clara County OWTS Ordinance No. NS-517.85, quoted and re-checked
16. Santa Clara County Department of Environmental Health (deh.santaclaracounty.gov)
17. Well Standards (California statewide rule), quoted and re-checked
18. Encroachment Permits | Caltrans (California statewide rule), quoted and re-checked
19. Planning Services, quoted and re-checked
20. Owner-Builder Responsibilities (California statewide rule), quoted and re-checked

Written October 10, 2026 from the rules quoted below, each taken from an official source and re-checked by an independent reviewer. This is research, not legal advice: rules change, so confirm with the office before you buy or build.