Accessory Dwelling Units, Done Right.

We're committed to helping increase efficiency in the housing market. We evaluate and manage Accessory Dwelling Unit construction for home expansion and rent.

Free home qualification

Building an ADU

Accessory Dwelling Units can provide an easy source of rental income for homeowners and low-cost housing for renters. Aside from its financial benefits, many homeowners seek ADUs to expand their home for personal or professional use.

We'll help you identify if expansion makes sense for your home, and what legal and development factors to think about, including managing the entire construction process.

An Accessory Dwelling Unit is a unit that can be added to an existing single-family home. ADUs can be detached (a separate building), attached to or part of the primary residence, or a garage conversion. ADUs are independent rental units that have their own kitchens, bathrooms, living areas, and entrances.

Are you considering building an ADU but don't know if you properly meet requirements and regulations? Are you unsure of which type of ADU will add the most value to your existing property? Despite easing regulations that make it possible to build expansions to your home, there are still many complexities to consider. We're here to help guide you.

Full-service design and build services


1. Qualification

Make an appointment for a free evaluation. We do pre-approval qualification and guarantee 100% financing. *Low interest financing options available.


2. Evaluation

We come to you for an evaluation of the property and zoning. Documentation for project scope and cost is provided.


3. Pre-Construction

We conduct a site survey analysis and begin preliminary planning, design, and engineering involving scope, and schedule to build on time and in control.


4. Construction

We project manage the entire design and construction process. On completion, we perform post-construction quality testing and maintenance.

At EcoSmart Builders, we are committed to providing leading edge construction solutions for designing, engineering, and building accessory dwelling units (ADU).

What are accessory dwelling units?

Accessory dwelling units, or ADUs, are small add-on residential buildings that can be used for housing or a variety of home applications. These functional buildings can be attached to the single-family home at ground level or constructed above a garage, or detached as a separate backyard ADU unit. Not only do they add value to the existing property, they can also provide additional revenue as a rental. They are becoming increasingly popular in Los Angeles County due to the short supply of affordable housing, and they offer an excellent opportunity for supplementary income.

EcoSmart Builders is one of the leading developers of sustainable accessory dwelling units in LA County. Whether you're considering adding an extra housing unit, a home office, a home gym, or any additional space to your residence, EcoSmart Builders has the architectural and construction expertise to deliver exceptional results regardless of project scope. Here is what we offer:

Accessory Dwelling Unit Design

We simplify the process of developing attached or detached accessory dwelling unit plans. Our project management team partners with you to design the optimal unit for your needs and goals. From the property evaluation, to securing financing, designing the unit itself, we offer a full spectrum of services that streamline the project, saving you time, money, and materials.

We also specialize in garage conversions, which create fully livable spaces from existing garages. These can either be build atop an existing garage or a complete conversion of the garage itself.

Accessory Dwelling Unit Floor Plans

If you want to add an ADU to your property but don't fully understand what will be involved, we can help. Our project management team will work with you to determine the extent of the home expansion, to help you secure financing, to develop the optimal floor plan for your needs and goals, help you understand the legal parameters, and much more.

We strive to be more than just a construction resource -- we're your long-term partner in the conception, development, and execution of your accessory dwelling unit. Our commitment to sustainability, customer support, and efficiency sets us apart from other ADU developers, and our dedication to craftsmanship ensures the longevity and integrity of all of our structures.

We're ready to help you build your future.

Types of Accessory Dwelling Units

attached adu

Attached ADU

These additions adjoin the primary home - to the side or rear of the home, or constructed on top of an attached garage.

detached adu

Detached ADU

A stand-alone structure separate from the primary home. A detached ADU can be built as entirely separate unit or constructed over an existing accessory structure, such as a detached garage.

adu garage conversion

Garage Conversion ADU

Convert your garage into living space - can be one of the quickest and most affordable ways to add usable space to a home.

junior adu

Junior ADU (JADU)

Built by converting an existing part of your home. e.g. a spare bedroom or attached garage. JADUs function as a regular ADU but do not exceed 500 sq.ft.

Learning Hub

ADU learning hub.

Building an ADU on your lot

You are permitted up to two ADUs on a single family zoned property. If you are considering two ADUs on your property, it is restricted to one full Accessory Dwelling Unit (ADU) and one Junior Accessory Dwelling Unit (JADU).

How big can I make an ADU?
There are some limits on the size of an ADU, based on the size of your lot and existing house. First, an attached ADU cannot be bigger than 50% of the existing house. For example, if your existing house in 2,000 sq. ft., the attached ADU cannot exceed 1,000 sq. ft. in size. Second, there is a “mansionization ordinance” that usually restricts the total square footage of all structures on a lot to 45% of total lot size. For example, if your lot is 10,000 sq. ft., the total built area (existing house, ADU, garage, etc.) cannot exceed 4,500 sq. ft. In addition, most ADUs cannot exceed 1200 sq. ft. The Dept. of City Planning will need to verify the specifics related to your project. You can build a detached ADU up to 800 sq. ft. and 16' tall without any local discretionary approvals.  ADUs created by conversions are also granted automatic approval.

My lot is small or unusual. Can I still build?
Almost every lot in LA is unique, so we're addressing the most common conditions. There are various types of ADU that work on different lots. For example, if a detached ADU will not fit in your backyard, you might attach a new unit to your current house. If the garage behind your house is inconveniently located, you could demolish and rebuild it with an ADU above. We can help sketch ideas and come up with development ideas in our free on-site consultation.

Eligibility to add a unit.

Single family homes with extra space in the backyard, a backyard garage, or a room that can be converted into a unit with a private entrance meet the space requirement. If the home is also located within 1/2 mile from public transit and/or has room for an additional parking space, you may be able to build an ADU.

To build an ADU, your current house must be located in a residential zone, and most likely in a single- family residential zone. ADUs are permitted in all single-family zones. Any lot in these zones, regardless of its size, can add an ADU if it will fit. Your lot must have an existing house, only one ADU per lot is permitted, and the ADU cannot be sold separately from the house. An ADU must meet additional site requirements as well as building construction requirements.

Ministerial approval of ADUs are within 60 days of receiving the application in cases where there is an existing single family dwelling on the lot.

Unpermitted ADUs are given 5 years to be brought back up to code.


Depending on the type of unit that makes sense for your home/lot, the below must be met before you can starting building your ADU. You can build a detached ADU up to 800 sq. ft. and 16' tall without any local discretionary approvals.  ADUs created by conversions are also granted automatic approval.

Detached unit on my lot
Max 1,200 sq.ft
5 ft min. from side and rear property lines
10 ft min. between main house and ADU

Attached unit to my home
No more than 50% of existing house and max of 1,200 sq.ft
Side and rear setbacks as required by zoning

Backyard garage conversion
Max 1,200 sq.ft
No change to existing setbacks

Attached unit to backyard garage
Max 1,200 sq.ft
5 ft min. from side and rear property lines (for ADU only, not garage itself)
10 ft min. between main house and ADU

Junior ADU
Max 500 sq.ft
Built by converting an existing part of your home. e.g. a spare bedroom or attached garage

*Parking considerations are attached for each type of ADU


How much space will I need for parking? Many lots already accommodate two parking spaces in a garage or carport. It is required to fit one extra parking space per unit/bedroom (ADU) on your lot if you are located more than one-half mile from public transit.

Additional parking is not needed if:
1. ADU is located within one-half mile of public transit.
2. ADU is located within an architecturally and historically significant district.
3. ADU is part of the existing primary residence or an existing accessory structure.
4. On-street parking permits are required, but not offered to occupant of the ADU.
5. There is a car-share vehicle located within one block of the ADU.

No replacement parking is required for the primary residence when a garage is demolished or converted to create an ADU. Detached, attached, interior, and detached demolished garage conversions are ADU types that do not require any parking.

*Parking requirements may change. Check with the Dept. of City Planning for current requirements.

Selling an ADU.

No, you can only sell your house and ADU together. ADUs can be rental units or occupied by the homeowner or family members. You can rent out both your home and ADU.

Funding ADU construction.

If you are not paying directly out of pocket, you will need some source of financing to start construction on your ADU project. It is always better to sort out the scope of the project with a budget attached as a first step, or at the very least, early on in the design and feasibility process.

Getting qualified for financing will help you determine what your budget is for the project and what the returns will be (if you intend the ADU to generate income).

We handle every stage in planning including securing different financing options if needed. We have an available 100% financing pre-approval process. *Low interest financing options available.

Elevate your lifestyle with extra living space or see immediate value with competitive rental income. Build your opportunity today.