Alamo is known for its spacious estates, rolling hills, and peaceful charm—making it an ideal location for building an Accessory Dwelling Unit (ADU). Whether you want to create a guest house, a private suite for extended family, or a detached home office, an ADU provides flexibility, comfort, and long-term value.

At Royalty Builders, we specialize in crafting custom ADUs that blend seamlessly with your property’s architecture and the surrounding neighborhood. From initial design to final inspection, we manage every detail—offering a smooth, high-end experience from start to finish.

Types of ADUs We Build in Alamo

Properties in Alamo offer ample space and architectural beauty, which gives us room to design ADUs that are both functional and elegant. Whether your lot is flat, sloped, or nestled among trees, we’ll create an ADU that fits naturally.

We specialize in:

• Detached ADUs – Perfect for guest houses, private rental units, or multigenerational living

• Attached ADUs – Elegant extensions that enhance your home without disrupting its flow

• Garage Conversions – Transform your garage into a polished, livable space

• Above-Garage ADUs – Smart, vertical solutions ideal for smaller lots or private studios

• Basement Conversions – Maximize existing space with a fully equipped lower-level unit

Every design is customized to align with Contra Costa County regulations and any applicable HOA or neighborhood guidelines in Alamo.

Full-Service ADU Design + Build in Alamo

At Royalty Builders, we offer a complete design-build service, meaning we handle everything in-house—from architecture and engineering to permits and construction. You get one team, one point of contact, and one beautifully executed project.

Our services include:

• Property analysis and zoning review

• Custom architectural plans and 3D visualization

• Engineering and Title 24 energy compliance

• Full permitting through Contra Costa County and HOA coordination (if required)

• Quality construction and high-end finishes

• Final inspections, utility tie-ins, and occupancy clearance

We combine luxury and functionality to create ADUs that elevate your home.

How Much Does It Cost to Build an ADU in Alamo?

Alamo properties often call for premium finishes and tailored design—which is why we work closely with each homeowner to create a plan that fits their budget and expectations. We provide clear, itemized pricing and help you make informed choices.

Typical ADU pricing in Alamo:

• Garage Conversion: $130,000 – $180,000

• Attached ADU: $190,000 – $310,000

• Detached ADU: $225,000 – $400,000+

• Above-Garage ADU: $240,000 – $420,000+

We can also guide you through ADU financing options that help you fund your project without compromising quality.

Permits for ADU Construction in Alamo – What You Need to Know

While Alamo is an unincorporated area governed by Contra Costa County, many neighborhoods have HOA requirements or custom design standards. We have deep experience working with the county and local review boards, so we ensure your ADU meets every requirement.

We handle:

• Lot and zoning assessments

• Permit documentation and plan submittals

• HOA architectural review (when applicable)

• Revisions and corrections

• Final inspections and occupancy approval

Our team manages every phase of the permitting process—so you don’t have to.

Why Build an ADU in Alamo?

Alamo is one of the East Bay’s most prestigious communities, offering privacy, luxury, and long-term investment potential. An ADU allows you to increase your usable living space without altering your lifestyle or relocating.

Top reasons Alamo homeowners are building ADUs:

• 🏠 Private space for guests, staff, or family members

• 💼 Elegant home offices or creative studios

• 💰 Rental income in a high-value neighborhood

• 📈 Higher resale value and broader market appeal

• 🔁 Aging in place or future downsizing—on your terms

ADUs in Alamo blend luxury with practicality—making your property more livable, flexible, and valuable.

Frequently Asked Questions – ADUs in Alamo

Q: Can I build an ADU on my property in Alamo?
A: In most cases, yes. We’ll evaluate your lot and zoning to confirm what’s possible based on Contra Costa County codes and any HOA requirements.

Q: Do I need HOA approval?
A: Many Alamo properties are within HOA-governed areas. We’ll manage all communication and submittals for architectural review.

Q: How long does the process take?
A: Most ADUs take 6–10 months from design to completion, depending on complexity and permitting.

Q: Can I rent out my ADU in Alamo?
A: Yes. Long-term rentals are permitted for fully permitted ADUs. We’ll make sure your unit is compliant with county and local guidelines.

Contact Royalty Builders – Alamo’s Trusted ADU Contractor

Looking to create a beautiful, functional, and fully compliant ADU in Alamo? Whether it’s a guest house, rental suite, or private office, Royalty Builders is your trusted partner for thoughtful design, expert permitting, and premium construction.

📞 Contact us today and schedule your free ADU consultation in Alamo.

Designed with care. Built with confidence. Delivered by Royalty Builders.