UNI Construction builds detached and attached ADUs, handling site planning, structural engineering, and permit-ready drawings. Options include backyard cottages, granny flats, and in-law suites, all code-compliant and tailored to your property.

UNI Construction – ADU Contractor in Diamond Bar, CA

About UNI Construction

ADU Construction Services by UNI Construction

UNI Construction offers a range of accessory dwelling unit services, covering both detached and attached ADU builds. Their work spans the full project scope — from initial design through to permit-ready documentation — making them a practical option for homeowners looking to add a secondary living space to their property.

Detached ADU Builder

As a detached ADU builder, UNI Construction handles standalone units that are built separately from the main home. Their process covers the complete design phase, including:

  1. Site planning
  2. Structural engineering
  3. Permit-ready drawings

Each detached ADU is designed to be code-compliant and tailored to the specific conditions of the property. This type of unit — sometimes referred to as a backyard cottage, granny flat, or Casita — is a separate structure that provides independent living space without being physically connected to the primary residence.

Attached ADU Construction

For properties where yard space is more limited, UNI Construction also works as an attached ADU builder. An attached accessory dwelling unit is connected to the existing home but includes its own entrance, kitchen, and bathroom, functioning as a self-contained living space.

UNI Construction designs attached ADUs to integrate with the existing structure of the home while still meeting all relevant building and zoning requirements. This type of unit is often considered as an in-law suite option, providing a practical solution for multigenerational living arrangements.

Whether the project calls for a detached ADU or an attached unit, UNI Construction manages the design and planning process with attention to local code compliance and the specific layout of each property.

Services

UNI Construction performs the following services

  • Architecture & Design
  • Permit Specialist
  • Feasibility & Site Assessment
  • 3D renderings & floor plans

UNI Construction Reviews

Forest Jones

2026-02-25
"I hired uni construction for my house's ADU project. I hired them after my first architect was taking forever to finish the design. Uni construction came in with better cost but more so solved many problems that architect had created! Now we are about to get permit. Strongly recommend"

Sonia Hobbs

2026-01-29
"I got uni construction to help with my ADU project. They did full design that helped me get city permit approval. City process was confusing but uni construction was very knowledgable to guide me through the process. i'm also discussing the construction for the ADU since their price is also good on construction. Strongly recommend!"

Pandora G

2025-11-20
"Im in the beginning stages of my ADU project, and as a homeowner this process can feel a little overwhelming, but working with Min Kang at Uni Construction has honestly made things so much easier. Hes been patient with all my questions and design changes, and communication has been great the whole way through."

I-Ting Wu

2025-08-19
"We worked with Min and his team at Uni Construction for our patio permit project, and I cant say enough good things about the experience. Even before we officially moved forward, Min took the time to fully understand our needs and requirements. Unlike other companies, he was the only one who suggested a Zoom call to align on scope and share practical tips for navigating the permit process which was incredibly informative and reassuring. Once the project began, Min remained consistently responsive and proactive, always working to achieve a faster turnaround. His guidance was clear, his fees very reasonable compared to other firms, and his service both reliable and professional. What really stood out was the balance of expertise and approachability. Min is not only highly knowledgeable but also personable and easy to work with. Thanks to him and the Uni team, what could have been a stressful process turned out smooth and efficient. I would gladly recommend Uni Construction to anyone needing architectural or structural drawings. Truly a 5-star experience."

Josue Moreno

2025-02-27
"I highly recommend Uni Construction for architectural plans. They did a great job on my plans for a detached ADU and getting them fully approved by the city. The plans were done quickly and you can trust that the job will get done right. I will definitely use them again for future projects."

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Specifics

Opening hours

Monday 8:00AM - 10:00PM
Tuesday 8:00AM - 10:00PM
Wednesday 8:00AM - 10:00PM
Thursday 8:00AM - 10:00PM
Friday 8:00AM - 10:00PM
Saturday 8:00AM - 10:00PM
Sunday 8:00AM - 10:00PM

Location

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