ADU Additions
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ADU Additions
Complete Design and Build Services by Riva and Cal Construction
Looking to add more space and value to your property? At Riva and Cal Construction, we specialize in designing and building high-quality Accessory Dwelling Units (ADUs) in Santa Rosa. Whether you’re planning a guest house, rental unit, in-law suite, or private office, we make the entire ADU process simple and stress-free.
From architectural plans to permits, construction, and finishing touches, we manage every detail of your ADU project so you can enjoy a seamless experience and a beautiful finished product.

Concrete Services
Full-Service Planning & Design
Our team works with you to create a custom ADU layout that fits your space, budget, and goals. We handle architectural drawings, structural planning, and all necessary submittals.Permit Handling
Navigating Santa Rosa’s permitting process can be complex, but we’ve got it covered. We coordinate directly with city officials to ensure your ADU meets all zoning, safety, and building requirements.Electrical & Plumbing Installation
Our licensed professionals ensure your ADU is fully equipped with safe, modern electrical systems and plumbing that’s built to last.
Interior & Exterior Finishing
From flooring and cabinetry to roofing and siding, we provide high-quality finishes that blend seamlessly with your main home—or make a statement of their own.Detached or Attached ADUs
Whether you’re building an ADU above a garage, converting a basement, or creating a standalone unit in your backyard, we tailor the build to suit your property and needs.- Upgrading Your Current ADU
We can renovate and upgrade your current building to bring it up to code, improve the aesthetic appeal, and completely gut out to start new.
At Riva and Cal Construction Inc., we specialize in designing and building custom homes that reflect your unique style and needs. Our experienced team ensures a seamless process from concept to completion, delivering a high-quality home tailored to your vision.
Make Residual Income With an ADU
Choose Riva and Cal Construction to Build your ADU
Local expertise in Santa Rosa ADU requirements
Full-service design + build under one roof
Transparent timelines and competitive pricing
High-quality craftsmanship and attention to detail
An ADU is more than just an addition—it’s an investment in your home’s future. Trust Riva and Cal Construction to deliver a functional, stylish, and code-compliant space that fits your lifestyle and boosts your property value.
