Campbell

ADU Builder in Campbell, CA

Campbell punches above its weight as an ADU market. It’s a small city by square mileage, but its established neighborhoods, walkable downtown, and easy access to San Jose and the broader South Bay job market make it a consistently strong destination for renters. The city has also put real infrastructure behind ADU approvals,  an online permitting portal, pre-approved plan options, and clear timelines, which means fewer delays from application to build. 

Apex Homes has navigated this process in Campbell many times and handles everything from the first zoning check through final inspection.

 

ADU Regulations in Campbell

Campbell follows California’s state ADU law with its own local overlay. Rules vary slightly by property type and ADU size.

Single-family lots (R-1)

• One detached or attached ADU + one Junior ADU (JADU) permitted
  • Detached ADUs: up to 1,200 sq ft
  • Attached ADUs: up to 50% of the main home’s living area, maximum 1,200 sq ft
  • JADUs: up to 500 sq ft, converted from existing interior space
• Setbacks: 4 ft side and rear for units ≤850 sq ft (or 2BR units under 1,000 sq ft); 5 ft for units built above a garage
• Height: detached ADUs within setback areas up to 16 ft; attached units outside setbacks up to 25 ft

Multi-family lots (R-2+)

• Up to 2 detached or attached ADUs, each up to 1,200 sq ft
• Detached units up to 18 ft in height
• Minimum 6 ft separation required between detached ADU and other structures

Apex Homes handles zoning verification, setback calculations, and code compliance — included in your free feasibility study. 

 

The Campbell ADU Permitting Process

Campbell uses California’s ministerial approval pathway, capping city review at 60 days by state law. Applications are submitted online through Campbell’s MyGovernmentOnline (MGO) portal, which lets you track status and respond to comments without visiting city offices in person.

Feasibility Study

Apex confirms your zoning classification, setback clearances, and lot coverage limits before any drawings are started. This is free and takes place before you commit to anything.

Select a Pre-Approved Plan

Campbell accepts Apex’s pre-approved ADU designs, which have already passed architectural and structural review. Choosing one eliminates the need for custom plan check — which cuts both cost and permit timeline significantly.

Pre-Submittal Consultation (Optional but Recommended)

Campbell’s Planning Division offers a pre-submittal meeting to clarify site-specific requirements before you file. Apex coordinates this on your behalf when it’s likely to reduce surprises during review.

Apex Submits Your Permit Package

We prepare and file your complete application through the MGO portal: site plan, architectural drawings, Title 24 energy compliance, and all supporting documents.

Construction & Inspections

Once the permit is issued, Apex manages the full build. All city inspections are coordinated through the MGO portal. Most projects reach move-in ready within five months of the feasibility study.

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Pre-Approved ADU Plans in Campbell

One of the biggest advantages for homeowners in Campbell is access to the city’s Pre-Approved ADU Program. These plans are created by licensed architects and meet all local and state building codes. By choosing a pre-approved design, homeowners can save on design costs and reduce permitting time, making it much faster to start construction. These plans are especially well-suited for detached backyard ADUs, which are among the most popular choices for Campbell homeowners.

Currently, Campbell’s pre-approved models include:

 

 

Why Build an ADU in Campbell?

Campbell is a vibrant community tucked into the heart of Silicon Valley, just southwest of San Jose. Like much of the Bay Area, it faces a persistent housing shortage, which creates a strong demand for well-designed rental units. A thoughtfully built ADU in Campbell can easily rent for $2,000 to $3,500 per month, depending on size and finishes. Professionals working in nearby tech companies, students, and retirees alike look for modern, private housing options, making ADUs a reliable source of long-term rental income.

The financial benefits don’t stop at monthly rent. Adding an ADU can increase a home’s value by 15 to 30 percent or more. Appraisers count ADUs as part of the property’s usable living space, and buyers increasingly see them as a valuable assets. With Campbell’s desirable school districts and established neighborhoods, homes with ADUs often stand out in the market.

For many homeowners, though, the most meaningful advantages of an ADU is the flexibility it brings to family living. An ADU can house aging parents who want independence while staying close to loved ones, provide a private space for extra living, or serve as a comfortable home for a live-in caregiver. Guests and long-term visitors also benefit from the privacy and convenience of their own dedicated space.

For more detailed information or specific guidance, we can book a free consultation with an Apex Home ADU expert. Let us help you transform your property with a thoughtfully planned ADU today!