ADU BuildersBuilders
in Orange County
An ADU is the versatile heart of your property. We design and build accessory units that bring families together, beautiful, functional spaces built for modern living, guest housing, and long-term value.
An ADU build is one of the most strategic investments you can make in your property. Not only does it significantly increase home value and provide immediate rental income potential, but it offers essential flexibility, creating private space for family, guests, or a dedicated home office. For homeowners, an accessory unit is a powerful asset for multi-generational living.
The Advantages of Building an ADU
Signature ADU Projects
From modern detached units to high-end garage conversions, our projects reflect quality craftsmanship, thoughtful design, and attention to detail.
We believe a great ADU build should add lasting value to your property.
Why Choose MDM General Contractors
01.
We’re a fully licensed and insured Orange County general contractor, delivering reliable, code-compliant ADU construction with professionalism and care.
02.
Explore premium materials, finishes, and ADU layouts in our showroom, guided by our in-house designer to bring your small-space vision to life.
03.
From planning and permits to construction and final walkthrough, your ADU project is managed by a dedicated team for a smooth, stress-free experience.
04.
We focus on detail-driven workmanship, clear timelines, and honest communication—so you know exactly what to expect at every stage of your build.
Our ADU Construction Process
We guide you through every phase of your ADU journey—from initial feasibility to the final certificate of occupancy—ensuring your project is built to the highest standards of quality and compliance.
Site Feasibility
We analyze your property’s zoning and utility requirements to ensure a viable and budget-friendly plan.
Design & 3D Modeling
Our team creates custom architectural plans and 3D renderings so you can visualize the unit before building.
City Permitting
We manage the entire submittal and approval process to secure all necessary building and safety permits.
Site & Foundation
We clear the lot, install utility lines, and pour a precision foundation to support your new structure.
Framing & Systems
Our crews execute structural framing and install all high-efficiency plumbing, electrical, and HVAC systems.
Finishes & Handover
We complete all interior finishes and clear final city inspections to deliver your move-in-ready ADU.
FAQs
How much does it cost to build an ADU?
The construction cost of your accessory dwelling unit will vary on the type you choose. Converting an attic or basement will have fewer costs because you already have the primary structure built. However, you can drive up costs based on the type of materials and quality of features you use. Most of the time, attached ADUs are less expensive compared to detached versions. Again, the quality of materials and features will have a direct impact on price.
Above all, the cost of your ADU will be determined by several different factors. Contact MDM General contractor to receive an accurate estimate for your accessory dwelling unit.
How much does an ADU increase property value?
Determining how much an ADU will increase your property value is difficult because of the little research gone into the question. Additionally, accessory dwelling units are a relatively new idea, so people are still pinpointing the value of ADUs.
With that said, a study performed in 2012 found ADUs contributed 25% to 34% of each properties’ value. In addition to this finding, the study concluded accessory dwelling units improved the value of the home by an average of 51%.
Does adding an ADU increase property taxes?
California’s property tax rate is 1% of your entire property’s value. Any time your property is sold or adds new construction, like an accessory dwelling unit, the property is revalued. Since adding an ADU does increase the value of your property, you can expect property taxes to increase. Even so, your property taxes can only be increased by no more than 2% per the Consumer Price Index (CPI).