Types of ADU’s
Existing Floor Conversion
Convert an underused floor of your home — whether it’s a ground level, basement, or upper story — into a self-contained ADU. We design around your existing layout to maximize livable space with minimal disruption.
Existing Floor ADU — Convert an Underused Floor of Your Home Into a Private Unit
An existing floor ADU conversion takes space you already have — a ground-level floor, basement, or upper story — and redesigns it into a fully self-contained dwelling unit with its own entrance, kitchen, bathroom, and living area.
This approach is one of the most cost-effective ways to add an ADU because the space is already enclosed and often partially finished. At Uni Construction, we design floor conversions that work within your existing structure to create a comfortable, code-compliant unit with minimal disruption to your household.
Why Homeowners Choose Floor Conversions
No new construction footprint — your yard and lot coverage stay the same
Lower cost than new construction — walls, roof, and foundation already exist
No setbacks required — conversion ADUs within existing structures are exempt from setback regulations
Not subject to maximum ADU size limits — California law exempts conversions from the standard 1,200 sq ft cap
Great for homes with unused lower levels, bonus rooms, or oversized layouts
What Our Design Process Covers
Converting an existing floor requires careful analysis of the space and surrounding systems:
Separate entrance design: We identify the best location for an independent entry that provides privacy for both the main home and the ADU.
Kitchen and bathroom placement: Plumbing routing is planned to connect efficiently to existing supply and waste lines.
Fire separation: A one-hour fire-rated assembly is typically required between the ADU and the primary residence. We specify materials and assemblies that meet this standard.
Sound insulation: STC (Sound Transmission Class) rated assemblies are designed between the units for noise separation.
Egress compliance: Windows, doors, and exit routes are designed to meet California residential egress requirements.
HVAC separation: We design independent or zoned heating and cooling so each unit has climate control.
Common Conversion Scenarios
Ground-level conversion: Homes built on slopes often have a lower level that is partially below grade. These spaces typically have good ceiling height and direct exterior access, making them strong candidates for ADU conversion.
Basement conversion: Full or partial basements can be converted into ADUs. We address natural light requirements, moisture control, and egress compliance.
Upper-story conversion: Splitting a two-story home so the upper floor becomes an independent unit. This typically involves adding a separate staircase or exterior entrance.
Each scenario has unique structural and code considerations. Our feasibility evaluation identifies the best approach and gives you a clear picture of cost, timeline, and design options before you commit.
Have unused space in your home? Request a free feasibility report and we’ll show you what’s possible.
ADU Types
Detached ADU
A standalone unit built separately from your main home. We handle the full design — site planning, structural engineering, and permit-ready drawings — all code-compliant and tailored to your property.
Attached ADU
A unit connected to your existing home with its own entrance, kitchen, and bathroom. Ideal when yard space is limited. We design attached ADUs that integrate with your home's structure while meeting all building and zoning requirements.
Attached ADU
A unit connected to your existing home with its own entrance, kitchen, and bathroom. Ideal when yard space is limited. We design attached ADUs that integrate with your home’s structure while meeting all building and zoning requirements.
Attached ADU
Attached ADU
Detached ADU
A standalone unit built separately from your main home. We handle the full design — site planning, structural engineering, and permit-ready drawings — all code-compliant and tailored to your property.
Detached ADU
Detached ADU
FAQ
Questions? We’ll Make It Clear
ADU and construction projects come with a lot of questions—here are the answers we get most.
What are the different phases of a construction project?
Our construction project typically involves three main phases: Design: This is where your vision comes to life. Architects, engineers, and designers collaborate to create a detailed plan for your project, including blueprints, specifications, and material selections. Preconstruction: The groundwork is laid in this phase. Permits are secured, budgets are finalized, and a qualified contractor is selected to bring your plans to life. Construction Management: The physical building process takes center stage. A dedicated team oversees construction, ensures quality standards are met, and keeps the project on track with the schedule and budget.
What are the different phases of a construction project?
While not always mandatory, if your project involves unique features, structural challenges, or a significant amount of square footage, we’ll assist in procuring the right design team to facilitate your project.
How long does the construction process typically take?
The timeline for a construction project depends on several factors, including the project’s size, complexity, and permit requirements. However, during preconstruction, a detailed schedule will be established, providing a realistic timeframe for completion.
How much will my project cost?
Developing a realistic budget is crucial for any successful project. While preconstruction involves detailed cost estimation, the final cost can be influenced by material selections, unforeseen site conditions, or potential design changes. Uni Construction can provide you with best estimation based on specific set of drawings.
How do I believe you're the right fit?
We understand your concern. Here at Uni Construction, we focus on three key things to ensure we’re the right fit for your project: Relevant Experience: We’ve tackled projects similar to yours, so you know we have the expertise to bring your vision to life. Happy Clients: We’re proud of our track record and love to connect you with satisfied past clients to hear their experience.