As San Diego continues to grow, homeowners are getting creative with how they use their property. One of the smartest and most valuable ways to add livable space — and boost your property value — is by building a custom ADU in San Diego. Whether you’re looking to create a rental unit, a home office, a guest house, or an in-law suite, a custom Accessory Dwelling Unit (ADU) gives you flexible living space tailored to your needs.
At Coast Design Build, we specialize in designing and building custom ADUs in San Diego that not only enhance your property but also match your lifestyle and long-term goals.
What Is a Custom ADU?
An ADU, or Accessory Dwelling Unit, is a secondary housing unit located on the same lot as a single-family home. What sets a custom ADU apart is that it’s designed specifically for you — from layout and size to style, finishes, and functionality.
There are several types of ADUs:
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Detached ADUs (standalone units)
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Attached ADUs (built onto your existing home)
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Garage conversions
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Above-garage units
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Basement ADUs (if applicable)
A custom ADU in San Diego can be used for:
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Long- or short-term rental income
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Housing family members or aging parents
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Creating a private guest suite
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Working from home in a separate office space
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Increasing your property’s resale value
Benefits of Building a Custom ADU in San Diego
San Diego is one of California’s most ADU-friendly cities, thanks to relaxed zoning rules and faster permit processes. That makes it the perfect place to build your own personalized unit.
Here are some benefits of working with a custom ADU builder like Coast Design Build:
1. Maximized Functionality
Unlike prefab units, a custom ADU is built around your specific goals — whether you want a compact one-bedroom or a spacious two-bedroom layout with full amenities.
2. Seamless Property Integration
We design ADUs that complement the existing style of your home and landscaping, so your property looks cohesive and well-planned.
3. Increased Property Value
A well-designed ADU can significantly raise your home’s market value, making it a smart long-term investment.
4. Potential Rental Income
In a high-demand housing market like San Diego, your ADU could become a reliable source of passive income through long-term tenants or vacation rentals.
Why Choose Coast Design Build for Your Custom ADU?
As a top-rated custom ADU contractor in San Diego, Coast Design Build offers start-to-finish solutions. From permits and planning to construction and final inspection, we handle every aspect of your project with professionalism and care.
Here’s what you can expect:
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Free consultation and site assessment
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Custom architectural and structural design
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Help navigating San Diego ADU laws and permits
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Experienced builders and project managers
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High-quality finishes and eco-friendly materials
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On-time, on-budget completion
Our team stays up to date with local zoning regulations and California building codes, so you don’t have to worry about red tape or delays. We also provide guidance on design ideas, floor plans, and cost-saving solutions that still deliver stunning results.
How Much Does a Custom ADU Cost in San Diego?
ADU construction costs vary depending on size, design complexity, and finishes. On average, building a custom ADU in San Diego can range from $150,000 to $350,000+.
Factors that affect cost:
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Site conditions and existing structures
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Utility hookups (water, sewer, electric)
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Design preferences and material quality
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Whether the unit is detached or attached
We provide transparent, itemized estimates and work with you to align the project with your budget while maximizing value.
Ready to Build Your Custom ADU?
Whether you want to create a peaceful retreat, increase your home’s value, or generate rental income, a custom ADU in San Diego is a smart and versatile investment. At Coast Design Build, we’re here to turn your vision into reality — with creative design, expert construction, and a commitment to excellence.
📞 Contact us today to schedule a free consultation and learn how we can bring your dream ADU to life — right in your own backyard.
