Experienced & Licensed ADU Contractor
ADU Building Costs in Santa Clara County
The cost of building an ADU in Santa Clara County can vary based on the type, size, and complexity of the project. Garage conversions are generally the most affordable, while detached ADUs or units built above a garage tend to have higher costs. Below is a breakdown of typical expenses for an ADU build in Campbell.
Comprehensive ADU Cost Breakdown for Santa Clara County
Soft Costs
- Planning and Building Department Fees: $10,000-20,000, depending on the size of the ADU and whether it is a conversion or a new construction.
- Water, Sewer, and Fire Sprinkler Connections: $10,000-20,000, contingent on whether the existing services can be shared or if new services need to be tapped at the street.
- PG&E Electric Hookup/Panel Upgrade: $5,000-8,000, depending on whether you have a 200 amp panel at the main house, if a new service is required, and the distance the gas line needs to run from the shared meter (or opt for all-electric and add solar!).
- Architectural Plans and Engineering: $15,000-35,000 for architectural plans, structural engineering, Title 24 energy modeling, and possibly a soils report. Garage conversions may require less in terms of engineering and soils reports, whereas stand-alone ADUs require more extensive structural engineering and may need a soils report.
Building Costs
- Garage Conversions: $150,000-300,000, depending on the condition and size of the existing garage, proximity to utilities, and the extent of necessary upgrades.
- Stand-Alone or Attached ADUs: $300,000-700,000, depending on size, site, accessibility, finishes, and building department requirements. Smaller ADUs typically cost around $650-700 per square foot, while larger ADUs over 800 square feet may see reduced costs due to economies of scale, especially with simpler designs and finishes.
Why Choose ADU Solutions of Campbell?
Our Seamless ADU Construction Process
Building an Accessory Dwelling Unit (ADU) in Campbell, CA can be complex, but with ADU Solutions of Campbell, we make the process seamless, efficient, and stress-free. With over 10 years of local experience and deep knowledge of Santa Clara County’s ADU regulations, we handle every step from start to finish—ensuring your project is completed on time, on budget, and to the highest standards. Here's how our licensed ADU experts bring your vision to life:
Step 1: Initial Consultation and Project Goals
Step 2: Property Evaluation and Financing Guidance
We start with a free consultation to understand your goals and vision. Whether you're building an ADU for rental income, a home office, or a guest house for family, we tailor every detail to fit your needs. During this phase, we’ll discuss:
- Purpose of your ADU (rental unit, in-law suite, guest house, etc.)
- Desired design features (number of bedrooms, bathrooms, square footage)
- Architectural styles that complement your primary residence
Establishing clear goals helps us craft a design that perfectly aligns with your vision and budget.
Step 2: Property Evaluation and Financing Guidance
Step 2: Property Evaluation and Financing Guidance
We conduct a thorough site evaluation to determine the best location and type of ADU—whether it's a detached unit, attached addition, or a garage conversion. We also:
- Assess property zoning laws and setback requirements specific to Campbell, CA
- Provide guidance on financing options—whether you’re paying out of pocket or seeking an ADU loan
- Conduct a market analysis to estimate how much property value your ADU will add
With this information, we help you establish a solid plan and budget for your project.
Step 3: Customized ADU Design & Planning Services
Step 3: Customized ADU Design & Planning Services
Our design experts work closely with you to develop a custom ADU tailored to your property and needs. We focus on:
- Maximizing space while maintaining functionality and aesthetics
- Incorporating energy-efficient solutions and modern features
- Selecting materials and finishes that match your existing home
You'll have the opportunity to customize everything—from the floor plan to the roofing, windows, and exterior siding.
Step 4: Transparent ADU Bid & Pricing
Step 3: Customized ADU Design & Planning Services
Once your design is finalized, we provide a detailed bid outlining all costs associated with the project. This includes:
- Itemized pricing for materials, labor, and permits
- Clear timelines for each phase of construction
- A bid that can be submitted to your lender if you’re financing your ADU
Our transparent pricing ensures there are no surprises—just quality results within your budget.
Step 5: Permits & Professional Construction
Navigating Santa Clara County’s complex ADU permitting process can be challenging, but we handle it all for you. We:
- Secure all necessary permits and approvals
- Ensure compliance with local building codes and zoning laws
- Begin construction using our licensed, experienced builders
Our team works efficiently to ensure your ADU is built to exact specifications, on time, and on budget.
Step 6: Your New ADU is Ready!
Once construction is complete, your brand-new ADU is ready to use! Whether you're renting it out for passive income, housing family, or using it as a home office, your new space adds significant property value and versatility to your home.