San Jose is one of the most dynamic cities in California—blending urban opportunity with suburban charm. With home prices high and space at a premium, building an Accessory Dwelling Unit (ADU) is one of the most cost-effective and future-focused ways to expand your living space.

Whether you’re building for multigenerational housing, generating rental income, or creating a home office or guest suite, Royalty Builders is your trusted ADU contractor in San Jose. We offer full-service solutions—from concept to completion—that bring beauty, function, and long-term value to your property.

We specialize in designing ADUs that blend seamlessly with your home, fit your lot, and comply with San Jose’s streamlined ADU approval process.

🛠️ Full-Service ADU Design + Build in San Jose

Building an ADU in San Jose doesn’t have to be complicated. With Royalty Builders, you get an all-in-one design-build team that manages every aspect of the process—from the first sketch to final inspection.

✅ Property Evaluation & Zoning Check – We assess your lot to ensure it qualifies under San Jose’s ADU ordinances
✅ Architectural Design – We create smart, efficient floor plans tailored to your goals
✅ Permit Application & Processing – We handle all submittals to the San Jose Planning Department
✅ Licensed Construction – We build with care, craftsmanship, and long-term durability in mind
✅ Utility Coordination – Electrical, sewer, water, gas—we manage it all
✅ Final Inspection & Certificate of Occupancy – Move-in ready and fully code-compliant

From backyard cottages to stylish garage conversions, our team builds ADUs that not only look amazing but also serve your everyday life.

🧱 Types of ADUs We Build in San Jose

We offer multiple ADU types to suit your lot size, layout, and specific needs:

• Detached ADUs – Standalone units perfect for rentals, guest housing, or family members

• Garage Conversions – Turn unused space into a cozy, self-contained living area

• Attached ADUs – Add a connected yet private living space with a separate entrance

• Above-Garage ADUs – A great way to expand upward and preserve your yard

• Junior ADUs (JADUs) – Smaller conversions under 500 sq. ft. with shared facilities

Each ADU is custom-designed to fit your home’s style, your lifestyle, and your budget.

📍 Why Build an ADU in San Jose?

San Jose is one of the most ADU-friendly cities in California. With a growing population, housing demand, and generous lot sizes in many neighborhoods, ADUs offer a smart way to increase living space and property value.

✔️ Earn Rental Income – Long-term or short-term, San Jose’s rental market is strong
✔️ Support Family Needs – Accommodate parents, college-age kids, or caregivers
✔️ Add Home Office or Studio Space – Ideal for remote work, creative pursuits, or side businesses
✔️ Increase Property Value – ADUs significantly enhance resale appeal and ROI
✔️ Take Advantage of San Jose’s Streamlined ADU Program – Faster approvals, fewer fees

💲 How Much Does an ADU Cost in San Jose?

ADU costs in San Jose vary based on size, layout, utility access, and finishes. Here’s a general breakdown:

• Garage Conversions: starting at $90,000–$160,000

• Detached ADUs: typically range from $200,000–$400,000+

• Attached ADUs: average $175,000–$300,000

• Above-Garage Units: can range from $225,000–$375,000 due to engineering complexity

📌 We provide clear, itemized estimates and walk you through each line of the budget. No surprises. Just real planning and great results.

📝 Permits for ADU Construction in San Jose – What to Expect

The City of San Jose has made significant efforts to support ADU development through simplified regulations and an online portal. As your contractor, we handle all permitting and approvals—so you can focus on the big picture while we take care of the details.

Here’s how the process works:

🔹 Pre-Submittal Consultation (Optional):
We can meet with city planners to confirm early feasibility, setbacks, and height limits.

🔹 Application Submission:
We submit a complete ADU application package, including site plans, floor plans, Title 24 energy compliance, and structural calculations. San Jose allows electronic submissions to speed things up.

🔹 Plan Review (Up to 60 Days):
San Jose follows California’s law requiring ADU reviews within 60 days. Minor corrections may be requested, which we handle immediately.

🔹 Permit Issuance & Construction Start:
Once approved, we pull your building permits and begin construction—fully to code and in line with your approved design.

🔹 Inspections & Final Sign-Off:
City inspectors visit the project at key stages. We manage all scheduling, updates, and corrections as needed until your Certificate of Occupancy is issued.

🏡 Key San Jose ADU Facts:

• You can build up to 1,200 sq. ft. for detached ADUs

• No minimum lot size required

• Reduced or waived impact fees for units under 750 sq. ft.

• Junior ADUs (JADUs) allowed in many single-family homes

• No additional parking required for many ADU types if near transit or converting existing space

Our team has experience working with the San Jose ADU Universal Checklist, Online Portal, and Express Review programs—we’ll make sure your project moves smoothly and efficiently.

👷 Why Choose Royalty Builders as Your San Jose ADU Contractor?

We know San Jose. We know ADUs. And we know how to take a complex process and make it easy, transparent, and rewarding.

Here’s why homeowners choose us:

• 💼 Experienced ADU Design + Build Specialists

• 🧭 Permit Navigation Pros – We speak “city planning” fluently

• 🛠️ High-Quality Craftsmanship

• 🏡 Customized, Not Cookie-Cutter

• 🧑‍💼 Dedicated Project Manager for Every Build

We build more than ADUs—we build spaces that solve problems, support families, and deliver long-term value.

❓ Frequently Asked Questions – ADUs in San Jose

Q: Can I have both an ADU and a JADU on my property in San Jose?
A: Yes! In most cases, you can build one of each on a single-family lot.

Q: Will an ADU increase my taxes?
A: Only the new square footage is reassessed, so the tax increase is minimal relative to the added value.

Q: Can I rent out my ADU legally?
A: Yes. ADUs in San Jose can be rented long-term (30+ days). Short-term rentals are subject to city guidelines.

Q: Do I need to provide extra parking?
A: Not always. Parking requirements are waived in many cases—especially near transit or when converting garages.

📞 Contact Us – Let’s Build Your San Jose ADU

Your San Jose property is full of potential. Let’s unlock it with a beautifully designed, expertly built ADU that meets your needs today—and adapts for tomorrow.

📞 Call us today and schedule your free consultation.

Let’s create the perfect ADU—tailored to your property, your lifestyle, and your future.