Atherton is known for its luxury estates, spacious lots, and quiet tree-lined streets—making it an ideal location for homeowners who want to expand their property with a custom Accessory Dwelling Unit (ADU). At Royalty Builders, we specialize in high-end, full-service ADU construction tailored to meet the standards of Atherton’s discerning homeowners.

Whether you’re building a private guest house, a poolside retreat, or a luxury in-law suite, our team of experienced professionals handles the entire process from concept to completion.

Why Build an ADU in Atherton?

Atherton offers generous lot sizes, exceptional privacy, and a prestigious location in the heart of Silicon Valley. As property values continue to rise, adding an ADU can help you:

• Create a private residence for family or guests

• House live-in caregivers or staff

• Build a home office, art studio, or wellness space

• Increase your property value and long-term equity

• Future-proof your estate with multi-generational living options

Thanks to California’s updated ADU laws, even towns like Atherton must allow streamlined construction of compliant ADUs—making it easier than ever to expand your living space.

Full-Service ADU Design + Build in Atherton

At Royalty Builders, we offer a complete design + build experience with a deep understanding of the design standards and zoning requirements in Atherton. Our turnkey approach simplifies the process for busy homeowners and ensures the highest quality craftsmanship.

We handle every stage:

• Site Evaluation & Feasibility: We assess your lot’s zoning, access, and potential to determine the best ADU options.

• Luxury Design Planning: Work with our in-house designers to create a stunning and functional living space that complements your estate.

• Permit Management: We manage all submittals and communication with the Town of Atherton to secure fast, compliant approvals.

• High-End Construction: From foundation to finish, our team uses premium materials and expert techniques.

• Final Delivery & Support: We walk you through the completed ADU and remain available for any future questions or needs.

Whether you’re aiming for a guest house that blends seamlessly with your main residence or a sleek, modern unit tucked away in your backyard, we deliver results that exceed expectations.

Types of ADUs We Build in Atherton

Given the size and scope of many Atherton properties, the design opportunities are vast. We specialize in:

• Detached ADUs: Ideal for private guest houses, backyard cottages, or fully self-contained residences.

• Attached ADUs: Built as part of your existing home, perfect for in-law suites or extended family living.

• Garage Conversions: Convert an underused garage into a comfortable and stylish living area.

• Above-Garage Units: Make use of vertical space with a studio or suite built above your garage.

• Custom Luxury ADUs: Spa-inspired retreats, gym suites, wellness spaces, or creative studios designed with upscale materials and finishes.

No matter the purpose, we’ll tailor your ADU to match your home’s architecture and meet your lifestyle needs.

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

Atherton homeowners typically seek high-end, custom-built ADUs, and the pricing reflects the premium design, materials, and scale of these projects. General pricing ranges:

• Garage Conversions: $150,000 – $200,000+

• Attached ADUs: $250,000 – $400,000

• Detached ADUs: $300,000 – $600,000+

• Luxury Custom Builds: $500,000 and up

Factors influencing cost include:

• Architectural design complexity

• Premium materials and finishes

• Site access and grading

• Utility connections and upgrades

• Landscaping integration

• Smart home features and energy-efficient systems

We offer detailed estimates and personalized planning to ensure your investment aligns with your vision and value expectations.

ADU Permit Process in Atherton

Although Atherton has traditionally been conservative with new development, California’s ADU laws (like SB 9, AB 68, and others) have made it easier to build secondary units even in affluent towns. Our team is highly familiar with local codes and will guide your project through the Town of Atherton’s specific process.

We manage:

• Zoning analysis

• Architectural plans and documentation

• Permit application and submission

• Coordination with building officials and planners

• Response to city plan checks and revisions

With Royalty Builders on your side, you can trust your ADU will meet all building codes and design expectations in Atherton.

Frequently Asked Questions – ADU Services in Atherton

Q: Can I build a luxury guest house on my property in Atherton?
A: Yes. With updated state laws, ADUs are allowed on nearly all residential lots in Atherton, and many homeowners choose to build guest houses with high-end finishes.

Q: How big can my ADU be?
A: Most ADUs can be up to 1,200 sq. ft., depending on your lot size and local rules. We’ll assess your property and design within the legal limits.

Q: Do ADUs require separate utilities in Atherton?
A: Not always, but in luxury builds, separate meters and utility upgrades are often preferred for convenience and performance. We’ll help you plan accordingly.

Q: Will the ADU match the style of my home?
A: Absolutely. We specialize in custom design and will ensure the ADU integrates seamlessly with your home’s architecture and finishes.

Q: How long will the entire process take?
A: On average, it takes 7–11 months from planning to move-in, depending on the complexity and permit timing.

Why Choose Royalty Builders for Your Atherton ADU?

• 🏆 Experience with Luxury Properties

• ✅ Design + Build Efficiency – One expert team handles everything

• 🛠 Premium Craftsmanship using the best materials

• 📐 Tailored, High-End Designs to match your estate

• 🔍 Transparency & Communication throughout the process

• ⭐️ Outstanding Reputation across the Bay Area

We understand the expectations of Atherton homeowners and strive to deliver exceptional quality, service, and long-term value.

Ready to Build an ADU in Atherton?

Whether you’re building a luxury guest house, a private retreat, or a future rental opportunity, Royalty Builders is your trusted partner for ADU construction in Atherton. Contact us today for a free consultation and let’s bring your vision to life—beautifully, professionally, and on your terms.

Call us today and schedule a free consultation.