Tucked away in the hills above Redwood City, Emerald Hills is known for its serene setting, spacious lots, and stunning views—making it an ideal location for building an Accessory Dwelling Unit (ADU). At Royalty Builders, we specialize in designing and building high-quality ADUs in Emerald Hills that enhance your lifestyle, maximize your land, and increase your property’s value.

Whether you’re considering a guest cottage, in-law suite, or hillside retreat, our experienced team handles the entire process—from initial design to final inspection.

Why Build an ADU in Emerald Hills?

Emerald Hills is a hidden gem in the Bay Area, offering privacy, scenic beauty, and a residential feel that’s hard to find elsewhere. Adding an ADU here makes sense for homeowners who want to:

• Expand their living space for family, guests, or caretakers

• Add a peaceful home office, studio, or fitness room

• Create a rental unit for long-term income

• Accommodate multi-generational living with privacy

• Boost property value and future flexibility

With large lots and updated California ADU laws, Emerald Hills homeowners have the opportunity to add valuable and well-integrated living space—without compromising the charm of their property.

Full-Service ADU Design + Build in Emerald Hills

At Royalty Builders, we offer a complete design + build experience for ADU projects in Emerald Hills. From feasibility assessments to architectural planning, permits, and construction, we handle every step under one roof. That means fewer delays, less stress, and better results.

Here’s what you can expect:

• Site Evaluation & Planning: We assess your property’s slope, access, utilities, and layout to determine the most effective ADU type and placement.

• Custom Design: Our in-house team creates beautiful, functional plans that reflect your vision and complement the surrounding landscape.

• Permitting: We manage the entire permitting process with San Mateo County, ensuring compliance with local codes and hillside building regulations.

• Construction: Our skilled crews build with precision, using high-quality materials and practices suitable for sloped terrain.

• Final Walkthrough & Support: We inspect everything with you and remain available after the build for any follow-up support.

We’re experienced in building on hillside lots and understand the challenges that come with the unique geography of Emerald Hills.

Types of ADUs We Build in Emerald Hills

Every property in Emerald Hills is unique, and we offer tailored ADU solutions that make the most of your space, views, and style:

• Detached ADUs: Private backyard cottages or guesthouses, perfect for long-term rental or independent living

• Attached ADUs: Additional suites connected to the main home, ideal for family or visitors

• Garage Conversions: Efficient way to create living space within an existing structure

• Above-Garage Units: Great for maximizing views and square footage on smaller footprints

• Custom Retreats: Yoga rooms, home offices, art studios, or poolside guest suites—designed with elegance and purpose

We’ll help you determine the best option for your needs and site conditions.

How Much Does It Cost to Build an ADU in Emerald Hills?

Due to the unique terrain and luxury nature of many properties, ADU costs in Emerald Hills can vary, especially for hillside construction. General estimates include:

• Garage Conversion: $150,000 – $200,000

• Attached ADU: $250,000 – $400,000

• Detached ADU: $300,000 – $500,000+

• Luxury Custom Builds: $500,000 and up

Cost factors include:

• Site grading and foundation needs

• Slope stabilization and access improvements

• Interior design, finishes, and smart systems

• Utility upgrades (electrical, sewer, water)

• Permit and development fees

We offer a free on-site consultation and detailed quote, so you know exactly what to expect before the first shovel hits the ground.

ADU Permit Process in Emerald Hills

Emerald Hills is an unincorporated community in San Mateo County, which means permits are issued through the San Mateo County Planning and Building Department. Our team is highly experienced in working with the county’s requirements—especially for hillside properties that may involve:

• Grading permits

• Environmental or tree preservation concerns

• Setback and height compliance

• Parking solutions and access planning

We handle every aspect of permitting, making sure your ADU is fully compliant with both county and state regulations.

Frequently Asked Questions – ADU Services in Emerald Hills

Q: Can I build an ADU on a sloped or hillside lot in Emerald Hills?
A: Yes. We specialize in hillside ADUs and can design units with custom foundations, retaining walls, and terraced layouts to suit your terrain.

Q: How long does it take to complete an ADU project?
A: Most projects take 7–11 months, including design, permits, and construction. Hillside builds may take slightly longer depending on site prep.

Q: Can I rent out my ADU?
A: Yes. California law allows ADUs to be rented as long-term housing units. They cannot typically be used for short-term Airbnb-style rentals unless permitted locally.

Q: Will an ADU affect my property taxes?
A: Only the new ADU structure will be reassessed. Your main home’s base value remains protected under Prop 13.

Q: Are there design limitations in Emerald Hills?
A: ADUs must comply with county height, setback, and coverage limits, but there’s flexibility in design. We’ll guide you through every detail.

Why Choose Royalty Builders for Your Emerald Hills ADU?

• 🏞 Experts in Hillside & Sloped Lot Construction

• 🏗 All-In-One Design + Build Firm

• ✅ Permitting Pros Familiar with San Mateo County

• 🛠 Custom Designs Built with High-End Materials

• 📐 Flexible Plans to Maximize Views & Space

• 🌟 Dozens of Happy Clients Across the Peninsula

We bring the craftsmanship, planning, and project management you need to build a smart, beautiful, and lasting ADU in Emerald Hills.

Ready to Build Your ADU in Emerald Hills?

Let’s bring your ADU vision to life—beautifully integrated with the landscape, designed for function and comfort, and built to last. Contact Royalty Builders today to schedule your free ADU consultation and start planning the perfect addition to your Emerald Hills property.

Call us today and schedule a free consultation.