Accessory Dwelling Units (ADU)
What is an Accessory Dwelling Unit?
Accessory dwelling unit (ADU), Granny flat, in-law suite, converted garage, backyard cottage, basement apartment – second units go by many names, but are always a self-contained home smaller than the main house and legally part of the same property. Second units can take many forms and vary in size, but always contain everything someone needs to live, including a kitchen, bathroom and place to sleep. Second units typically range from 220 square foot studios to over 1,000 square foot houses with multiple bedrooms.
There are many different types of second units, but they are generally one of these types.
Reasons To Build An ADU
People build second units for lots of reasons, but the most common are rental income and/or to house relatives. Having a second unit is a simple and old idea to convert unused space. Second units are a relatively affordable type of construction, because they do not require purchasing land or major new infrastructure. Here are some of the reasons to build a second unit:
• Rental Income
• Housing for Relatives
• Downsizing
• Flexible Space
• Sound Investment
• Community Benefits
Check Your Zone Eligibility
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. Most standard lots are 3,500 sq ft or more, and may comfortably fit an ADU. Lots under 3,500 sq ft may face feasibility issues. Here are some additional guidelines to your ADU eligibility:
• Your lot must have an existing house
• Only one ADU per lot is permitted
• The ADU cannot be sold separately from the house.
• You must provide space for parking
See How to begin your ADU Project in These 5 Easy Steps!
You now have an idea of why people build second units, how they are used and what they look like. If you’re ready to begin the process of building your own second unit, here’s how to get started! There are generally five steps to building a second unit: research, design, permits, construction and move in. More information and specific details on each phase can be discussed by contacting us at MZN Construction and Engineering.
Fill out the form below, and we will schedule a time to meet with you.
Frequently Asked Questions
1. How much will my ADU cost? Since the size and construction of each ADU will differ, it is impossible to estimate the cost of your ADU. The cost per-square-foot of an ADU is likely to be the same as any other new residential construction; builders and architects can give you rough estimates.
2. How do I pay for my ADU? There are a number of ways to pay for the construction of an ADU. A common way is to borrow from a home equity line of credit if you have equity in your existing house. Other ways can be more complicated: 1. You could refinance your existing mortgage to take out a larger loan to provide cash for ADU construction (this will require equity in the home); 2. You may be able to obtain a private construction loan to build the ADU and refinance the loan with a new mortgage when construction is complete. You should start by talking to the bank that holds your current mortgage.
3. How do I tell if I’m Near Transit? Many lots in LA are within a half-mile of transit, so that ADU parking will not be required. The City publishes a transit map at media.metro.net/riding_metro/maps/images/system_map.pdf. First, see if your lot appears to be within a half-mile radius of a bus stop, rail station, or a dedicated space where a shared-vehicle is parked. Second, call the Dept. of Building and Safety to give your property address. They can confirm whether you need to provide parking for your ADU.
4. Can I Sell my ADU? No, you can only sell your house and ADU together. ADUs can be rental units or occupied by the homeowner or family members.
5. Must the homeowner live on the property? No, both the existing house and the ADU can be rental units.
6. What if my current garage is in the front of my lot? If your existing garage is at the front of your house, in most cases you cannot convert it into an ADU. You may be able to build an ADU elsewhere on your property. You should check with the Dept. of City Planning.
7. Can I legalize an non-permitted ADU on my lot? Although this guidebook focuses on new construction, you may be able to get permits that will legalize an existing rental unit on your property. You can contact the Dept. of Building and Safety for more information.
8. How big can I make my 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.
9. My lot seems too small or unusual. Can I still Build an ADU? Almost every lot in LA is unique, so this guide-book addresses 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. Sketch your ideas as suggested in the guidebook, and talk them over with the Dept. of Building and Safety.
10. Is an ADU subject to the Rent Stabilization Ordinance? If you add an ADU to your home, you can rent one or both of the units. If your home was built before 1979, one or both of the units may become subject to the City’s Rent Stabilization Ordinance (RSO).