Skip to content 
ADU Builders for Accessory Dwelling Units That Add Real Space
As experienced ADU builders, we help homeowners unlock flexible, well-designed space on their property through thoughtfully planned accessory dwelling units. Our approach blends clear communication, careful planning, and quality construction—so your ADU feels intentional, functional, and built to last.
Whether you’re expanding for family, planning for the future, or adapting how your house is used, we guide you through the process step by step
What Are AccessoryDwelling Units?
Accessory dwelling units are independent living units located on the same property as an existing home. Often called ADUs, these structures include their own kitchen or kitchenette, bathroom, living space, and sleeping area.
In California, ADUs have become a practical way to add housing flexibility without changing neighborhoods or leaving the homes people love.
Why Homeowners Choose ADUs
Many homeowners turn to ADUs to solve real-life needs. Some want room for extended family. Others want a private home office, guest accommodations, or a long-term living solution that adapts as life changes.
In markets like San Francisco Bay Area and Marin County, ADUs have proven their value—showing how smart design and careful planning can make smaller spaces work harder.
How ADUs Increase Property Value and Flexibility
A well-planned ADU can increase property value while making your property more versatile. Some owners explore rental income, while others focus on long-term livability rather than short-term returns.
Every ADU project starts with understanding your goals, your site, and what makes sense for your house.
Working With an Experienced ADU Contractor
As your dedicated ADU contractor, we manage the full scope of your project—from early feasibility through final inspection. That includes design, plans, permit coordination, and hands-on construction.
You’ll always know what’s happening, what decisions are needed, and what comes next.
Understanding YourADU Build Options
There are several options for adding an ADU, and the right choice depends on your property, layout, and budget. Your ADU may be detached, an attached adu, or created by reworking existing space like a garage or attic.
Custom ADUs Designed for Your Property
We specialize in custom adus that respond to real conditions—not one-size-fits-all templates. Each custom adu is shaped by zoning, setbacks, access, and how the new space connects to your existing house.
Our custom design approach ensures the ADU feels cohesive, not like an afterthought.
Prefab ADUvs Custom Build
Some attic remodels
A prefab adu can offer speed, but it often limits flexibility.
Site constraints, finish choices, and layout compromises can create challenges.
Some attic remodels
A custom build allows better alignment with your property.
Smoother approvals, and more durable results.
We explain these differences upfront so you can plan confidently.
ADU Design That Balances Comfort and Efficiency
Good ADU design prioritizes flow, storage, natural light, and privacy. We carefully consider bedroom placement, living areas, and circulation so smaller units still feel comfortable.
Strong design makes the most of every square foot.
Floor Plans and ADU Layout Planning
Thoughtful floor plans are essential to successful ADUs. Each adu plan is developed around how the space will actually be used—not just what fits on paper.
We plan layouts that feel intuitive, efficient, and adaptable.
Sub-Services: ADU Solutions We Offer
Attic & Basement Conversions
Attics and basements can become valuable living space when properly planned. We assess ceiling height, light, and access before recommending this option.
ADU Kitchenette
An ADU kitchenette is designed for efficiency and comfort. We balance appliance placement, storage, and workflow so the space feels complete without excess.
Guest House
A detached ADU can function as a guest house, offering privacy for visitors while maintaining connection to the main property.
Home & Room Additions
Some ADUs are created through strategic additions that expand a house without overwhelming the existing structure. These builds integrate seamlessly with the original homes.
Prefab & Modular ADUs
For certain sites, modular or ready ADU solutions may work well. We’ll explain where these options make sense—and where they don’t.
Garage Conversions
A garage conversion can turn underused garage space into a fully functional ADU. We evaluate structure, utilities, and access to ensure the conversion supports long-term living
Planning & Permits
We manage permit requirements, zoning checks, and submissions so your project stays on track and compliant.
Building ADUs for a Variety of Needs
ADUs support a variety of needs—from multigenerational living to creative studios or flexible rental arrangements. The key is matching the design to how the space will actually be used.
Our ADUBuild Process
Our build process is structured to reduce surprises and keep expectations clear. Each step is outlined before work begins so you understand timelines, decisions, and dependencies.
Step-by-StepADU Construction Overview
As your dedicated ADU contractor, we manage the full scope of your project—from early feasibility through final inspection. That includes design, plans, permit coordination, and hands-on construction.
You’ll always know what’s happening, what decisions are needed, and what comes next.
Permits and Local Requirements
ADUs require multiple layers of approval. Navigating permit requirements correctly protects your investment and prevents costly rework.
We handle coordination with local agencies and inspectors.
Clear Pricing and ADU Costs
Understanding ADU costs upfront matters. We provide transparent estimates and clear pricing based on scope, site conditions, and selected options.
No vague ranges—just honest guidance.
Magic AI Tool See Your Remodel in Seconds with AI
Fast, simple, and perfect for planning.
Construction Quality That Holds Up Over Time
Quality construction matters even more in compact living environments. Our builders focus on durability, clean finishes, and long-term performance.
ADUs as Guest Houses, Pool Houses, or Offices
ADUs can function as a pool house, private home office, or flexible guest space—without sacrificing the integrity of your property
One-Story and Story ADU Options
A story ADU or single-level unit depends on zoning, access, and how the space relates to the main house. We help you choose what works best.
Why Experienced Builders Matter
Choosing the right builders reduces risk and improves outcomes. Our team prioritizes accountability, communication, and craftsmanship throughout the project.
Why Mission Home Remodeling for ADUs?
We approach every ADU with care, clarity, and respect for your property. Our role isn’t just to build, but to guide you through decisions with confidence.
FAQs ABOUTFINANCING OPTIONS
We manage every stage of your project:
How long does it typically take to build an ADU?
Timelines vary depending on design complexity, permitting, and site conditions. On average, the full process—from initial planning and design through final inspection—can take several months. Clear planning and proactive permit coordination help keep the project moving efficiently.
Can I customize the interior finishes and features of my ADU?
Yes. From flooring and cabinetry to lighting and fixtures, interior finishes can be tailored to your preferences and budget. Customization ensures your ADU feels cohesive with your main home while reflecting your personal style.
Will adding an ADU affect my existing utilities?
An ADU may require upgrades or extensions to utilities such as water, sewer, and electrical systems. During the planning phase, we evaluate your current infrastructure to determine what adjustments are needed to support safe and reliable long-term use.
Do I need separate utility meters for my ADU?
Separate metering depends on local regulations and how you intend to use the space. Some homeowners choose separate meters for rental purposes, while others keep utilities connected to the main home. We review local requirements and help you decide what makes the most sense.
Can an ADU be built on a small or uniquely shaped lot?
In many cases, yes. Creative design solutions can help maximize limited or irregular spaces. Factors such as setbacks, access, and zoning regulations will influence feasibility, but thoughtful planning often reveals opportunities homeowners might not expect.