Turnkey ADU Construction

If you're thinking about adding an ADU to your property, you want a company that handles everything smoothly from start to finish. At Modern ADU Builder, we offer turnkey ADU construction services, meaning we manage the whole process for you, from design and permits to building and finishing. Our goal is to make ADU construction simple and hassle-free so you can focus on what matters most to you.


We know that navigating permits, design choices, and construction can be overwhelming. That’s why we take care of every step, keeping you informed along the way. With our experience and clear communication, you’ll know exactly what to expect and when your new ADU will be ready for use.


When you work with us, you get a partner who knows the local rules and builds quality homes designed to fit your needs. We believe the right ADU can add value and flexibility to your property without the typical stress of building a new structure.

What Is Turnkey ADU Construction?

Turnkey ADU service means the company handles every step of building your ADU. This includes design, permits, construction, inspections, and finishing. You work with one point of contact who coordinates all parts of the project.


This service removes the need for you to juggle different teams or handle paperwork. The goal is to make the whole ADU process seamless and clear. It’s especially helpful if you want a hassle-free experience and predictable results.

ADU Design Options

Custom Floor Plans

We work with you to design floor plans that fit your lot size and lifestyle. Whether you want a studio or a multi-bedroom unit, we create layouts that maximize space. We focus on useful room flow, natural light, and storage.



If you have special needs or ideas, we can include those in the plans. Our designs avoid wasted space and keep your ADU practical and easy to live in. You get a plan that matches your budget and goals.

Interior and Exterior Finishes

You have many options for finishes inside and outside your ADU. For interiors, choose from flooring types like hardwood, tile, or durable vinyl. Cabinets, countertops, and lighting can be selected to match your style and use.



Outside, you can pick siding materials, paint colors, and roofing styles. We help you pick finishes that last in your climate and fit the look of your main home. These details improve your ADU’s appearance and value.

Energy Efficiency Upgrades

We offer energy-saving features to reduce your utility bills and environmental impact. Options include efficient windows, LED lighting, and ENERGY STAR appliances. Proper insulation and sealing help keep the unit comfortable year-round.



You can also add solar panels or smart thermostats for more control over energy use. These upgrades lower operating costs and can increase your ADU's long-term value. We guide you in choosing the right solutions for your needs.

02 Site Preparation

We begin by assessing your property to plan the best layout for your ADU. This includes checking soil, grading, and any underground utilities. Clearing the site involves removing debris, leveling the ground, and marking boundaries.

02 Building Process

Our team follows a clear schedule to build your ADU efficiently. We start with the foundation, pouring concrete or laying slabs based on your site’s needs. Framing comes next, shaping the walls, roof, and windows to create the shell of the building.

03 Final Inspections

When construction is complete, we arrange all required city or county inspections. These ensure your new ADU meets safety and building codes. We review electrical, plumbing, structural, and fire safety standards.

Types of ADU Projects Offered

We provide a variety of ADU options that fit different property needs and goals. Whether you're looking to add space, rental income, or a flexible living area, we tailor each project to meet your requirements.

Detached ADUs

Detached ADUs are separate buildings from your main home. They give you the most privacy and can be placed anywhere on your property within zoning limits. These structures typically include a full kitchen, bathroom, and living area, making them suitable for long-term rentals or guests.

Attached ADUs

Attached ADUs connect to your existing home, often by remodeling or expanding available space. This option can be more cost-effective since it shares one wall with your main building, reducing construction materials and labor.

Garage Conversions

Converting a garage involves adding insulation, plumbing, and sometimes electrical upgrades. We ensure your new ADU meets safety standards and fits your needs, whether as a rental, office, or guest space.

Why Choose Us

We have helped many homeowners add space and increase property value with our turnkey ADU service. One client expanded their backyard with a modern studio that was completed in under four months, with no surprises in cost or timing.


Our clients often highlight the ease of working with us. They say we listen carefully to their needs and turn ideas into practical, well-built spaces. Your project will benefit from this same focused care and attention.

FAQs on Turnkey ADU Construction

Hi there! Have some questions about our service? Find the answers below. 

  • What are the estimated costs for constructing a prefab ADU in the San Diego area?

    Costs for prefab ADUs in San Diego typically range from $150,000 to $300,000. The final price depends on size, design, and site conditions. We help you understand all cost elements so you can plan your budget effectively.

  • How do I choose the best ADU builder near me?

    Look for builders with experience specific to your area. Check their portfolio, how they handle permits, and communication. We recommend choosing a company that manages design, permits, and construction smoothly, like we do.

  • What is the average timeline for completing an ADU construction with Modern ADU Builder?

    From design to move-in, most projects take about 6 to 9 months. This depends on permitting and site specifics. We provide schedules upfront and update you regularly during the process.

  • Are there any zoning or regulatory considerations when installing a prefab ADU in the Bay Area?

    Yes, local rules vary by city and county in the Bay Area. You must meet size limits, setback requirements, and sometimes parking rules. We assist with understanding and handling these regulations to avoid delays.

  • Can you list the advantages of selecting Modern ADU Builder for my Accessory Dwelling Unit project?

    We offer turnkey service covering design, permits, and construction. Our team stays involved through every step, so you don’t manage multiple contractors. You get a streamlined experience with transparent pricing and expert support.