Los Angeles Garage Conversion ADU in 2023 – Your Complete Guide

(Updated August 2023)

I recently did a garage conversion with a detached garage behind my home.  The garage was 468 square feet with the dimensions 18’ x 26’. I always wanted to convert my garage into a living space, but I didn’t know where to start.

I’ve known about the new laws and regulations in Los Angeles regarding ADUs, but I didn’t have the budget nor space for a new, freestanding ADU (see ADU definition here), so a garage conversion was the perfect solution. Now that I’ve gone through the process myself, I can share the steps I took and the things I had to consider.

There’s a lot to know – everything from developing plans, evaluating the garage conversion cost, and considering various requirements, to picking a floor plan and hiring a contractor.

Note: This article discusses high-level information about garage conversion projects throughout Los Angeles County. For detailed ADU information regarding your specific city, please visit the links at the bottom of this page.

Garage Conversion in Los Angeles   Credit: Pardee Properties

Here at GreatBuildz, a free service that connects homeowners in Los Angeles, Orange County, Ventura or San Diego with reliable general contractors, we get inquiries every day about garage conversions in Los Angeles – here are some tips to get you started.

Garage Conversion Plans

The first step is to find a small architect or design firm to draw the garage conversion plans with your guidance.  This is a pretty basic project, so you don’t need an expensive architecture firm.

They’ll be able to discuss different garage conversion ideas with you, and give you advice on which options will work best for you – depending on if you want to convert your garage to include a bedroom and/or bathroom, convert your garage into a rentable unit, or any other layouts.

When it comes to converting you garage into a new room, ADUs are definitely an option. However, one can also create a multipurpose space from a narrow ex-garage as opposed to making it into an ADU. You can also rework the layout of the rooms that the garage connects to by turning the garage into a section of room.

One example of this is if your garage connects to your family room and kitchen, you could incorporate the garage to be part of your family room or kitchen. In addition, one can also add a second story to the ex-garage, turn the place into a utility or cloakroom, and/or connect it to a garden. Lastly, these garages can also be turned into home offices, extra bedrooms, playrooms for kids, or home gyms.

In most cases, you’re likely doing very little with the exterior of the garage – just adding one wall where the garage door is currently, and installing a front door, sliding door, and windows – so that part of the design is reasonably basic. 

Garage Conversion To Bedroom    Credit: Pardee Properties

In addition, there shouldn’t be any extensive structural design as the exterior load-bearing walls are already in place. However, the architect/designer will still have to involve a structural engineer to assess the existing structure and add any structural elements necessary. 

Garage Conversion plans should cost you between $6,000 – $15,000 and should include the architects design, structural plans, Title 24, and anything else required by your city or municipality. This price should also include having your architect/designer submit your plans to the city, make plancheck corrections and get you an approved set of plans that’s ready for permitting.

Most of the design work involves the interior layout. As you can see in my garage ADU conversion floor plan below, I designed a ‘great room’ that included a living area, kitchen, and small eating area. I left enough room for a small bedroom with a closet, as well as a small full bathroom. A small bedroom would ideally be a minimum of 10’x9’ and a full bathroom is a minimum of 5’x8’.

(GreatBuildz can recommend a reasonably priced garage conversion plan designer if you need one)  

Garage Conversion Floor Plan in Los Angeles – Great Room    Credit: Pardee Properties

Once you’re happy with your plans, the architect will submit the plans to the city building department for plancheck. This approval might take anywhere from 2 weeks to several months, depending on the city’s backlog.  During that time, you can start sharing your plans with several General Conversion Contractors and having them each provide you with a cost estimate for your garage-to-room conversion.

Although you could act as your own ‘general contractor’ and hire sub-contractors to complete such a project, I highly recommend against it.  It is likely to be cheaper in price, but much, much greater in time and headaches.  Also, it’s not something you should consider unless you know of good subcontractors for all the trades involved (ie. plumber, electrician, drywall, tile, etc).     

Once you start construction, the entire process should take 2-3 months. Although most of the work will be contained to your garage, keep in mind your general contractor will need to dig trenches and install sewer & water (and potentially gas/electric) lines that run from your garage to the connections on the side of your house or front yard. This is the messiest part of the job.

Even once the project is complete, it could take a while before the DWP or your gas company comes to install your meter. Finally, don’t forget to obtain insurance for your new garage conversion ADU structure.

How To Find A Los Angeles Garage Conversion Contractor

A couple of suggestions about finding the right garage conversion contractor in Los Angeles.  It’s best to search for only local, licensed General Contractors. No other contractors are qualified or equipped to do this sort of construction, and using an unlicensed contractor or handyman would be a mistake.

Any contractors you contact, always confirm they have experience with ADUs. You’ll want to hire a contractor who has built ADUs or garage conversions in the past and therefore knows the potential issues/pitfalls. 

There are several other important criteria you should use in selecting a garage conversion contractor. Check for a valid contractor’s license on the Contractors State License Board website to confirm it is active, there are no disciplinary actions, and it has Workers Compensation insurance associated with it (assuming the GC has employees).

Make sure they’re insured and get a copy of their insurance certificate. Ask your contractor for at least three references you can call. Lastly, read their reviews online on Google & other contractor search engines.

If you want more tips on how to find and vet an ADU contractor check out my blog: 10 Tips To Hire an ADU Contractor

(At GreatBuildz, we take contractor screening seriously. We take all the steps above, in addition to running a background/financial check and requiring contractors to sign our 20-point Code of Conduct.  You can call our free service, speak with our friendly staff about your project, and get connected to several fully vetted, trustworthy contractors who are experienced with ADUs in Los Angeles. For more info, visit www.GreatBuildz.com or call 818.317.3567 today)

Garage Conversion Requirements: It’s All In The Details

Your designer’s plans will give contractors a majority of the information they need to understand the garage conversion cost to bid on the job, but they won’t have everything.  Most cities don’t require your plans to include details about electrical, plumbing, HVAC, etc., so you’ll need to provide your contractor with details of what you want. 

• For plumbing: you’ll need to decide where you want your water heater and if it’ll be with a tank or tankless; gas or electric.
• For HVAC: do you want a full HVAC system like you have in your home or do you want a small ‘ductless’ unit that is cheaper but services a smaller area?
• For electrical: how many outlets, lights, and switches do you need and where do you want them? Also, you’ll need to discuss with your contractor what kind of electrical panel you’ll need for the ADU.

In addition to these ‘major’ trade decisions, you’ll also want to consider if you need other items included in your garage conversion ADU:

• Do you need the garage to be re-roofed?
• Do you need any concrete work like a footpath, driveway, front stoop, etc?
• How about new fencing or landscape work in the yard?
• Would you prefer flat or vaulted ceilings?
• Is your garage floor currently flat or sloping? It might need to be leveled. 
• Will you be painting the exterior of the ADU? 
• Is there any termite or water damage to the existing garage that needs to be repaired? 
• Do you want a bathtub or just a shower? 
• What will your kitchen design look like? 
• Are your appliances included in the bid? 

Finally, the more detail you can give on your desired materials, the more accurate your contractor’s price can be. Can you pick out your tile, flooring, kitchen cabinets, lights, faucets, doors, windows, etc. in advance? If not, the contractor will likely give you a material ‘allowance’ in their bid; in which case you would pay the difference if you choose materials that are more expensive than the allowance in the bid.  

Credit: Pardee Properties

Los Angeles Garage To ADU Conversion Costs

How much does it cost to convert a garage to ADU in Los Angeles?

$100,000 – $130,000, Depending on your specific situation, is what you can expect for your garage conversion cost, including plans, contractor labor, materials, and city garage conversion permits. This garage conversion cost will vary based on the size of your garage and the improvements you want to include.

A garage conversion is certainly not an inexpensive project. So if you’re looking to build an affordable garage conversion, here are a few tips to consider to save costs.

Consider locating the bathroom next to the kitchen so that all your plumbing will go into the same wall. For the same reason, look to install the water heater and laundry as nearby as possible.

Additionally, if you can make your garage conversion “all-electric” (range, dryer, water heater), you wont need to run a new gas line from your gas main.

Lastly, try to limit the use of tile, as it’s expensive to install. There are other options to use on all flooring areas, kitchen backsplash, and even in the shower (fiberglass tub surround).

There are many other ways you can save on garage conversion costs, check out our Top 5 Cost Saving Tips for ADUs.

Garage Conversion Rental Income Property Floor Plan

There are many potential uses for garage conversions which include a bonus room, guest house, fitness studio, granny flat, etc; many Los Angeles homeowners are building ADUs for rental purposes. The latest State ADU laws allow owners to build an ADU and rent it out to a tenant, or even rent out both the existing home and the ADU (essentially creating a duplex scenario).

There is a lot to consider if you’re planning to build an ADU for rental cash flow, so I suggest you review our complete blog on ADU rentals. When it comes to the Return on Investment (ROI) of an ADU Garage Conversion, there are two ways to look at it. First, it will increase the long-term value of your property when you decide to sell. The exact amount of increase is hard to gauge as ADUs are still a new concept that many appraisers don’t have a consistent method for evaluating. Regardless of the actual increase in value, there is no question that a buyer would pay more for a property with a garage conversion or accessory dwelling unit.

The other portion of financial return comes from the cash flow of renting the garage conversion. Rents are currently high in Los Angeles and Southern California, so you can expect your annual rental income to be reasonably high. Don’t forget to subtract expenses to calculate the true ROI. Expenses include insurance costs, utilities that aren’t paid by the tenant, maintenance, and leasing costs. Take your net annual income from the rental and divide by the money you spent building the garage conversion, and there you have your annual ROI.

If you’re an investor that’s planning on taking a single-family home and adding a garage conversion ADU so you can rent out both units to enhance the cash flow from a property, this blog about ADUs for Real Estate Investors has some information that will help in your research & planning.

Comparing Garage Conversion Costs

The next step is to compare your contractors’ bids. Be careful not to just look at the price, but also carefully compare the scope of work. Bids can be very inconsistent among contractors.

Let’s face it, when you meet with three different people, they may hear three different things (and maybe you even forgot to mention something in each case).  But, that’s why it’s important to carefully review and compare all bids for consistency. Garage Conversion ADU costs can vary drastically between contractors, so it’s important to review their bids carefully.

In a perfect world, you’d have your own ‘master list’ of all the items that should be in the bid that you can use to compare all bids against. See my ADU Checklist article for a full list of requirements you can use as a resource. Ideally, you can prepare this ADU checklist as you decide what you want to be included in your ADU garage conversion, and then hand it to every contractor you meet with.

That will help ensure your contractor bids are as consistent as possible. If any contractor’s bid is missing something or unclear, make sure they revise the bid so that you can review all your estimates ‘apples to apples’. 

A few more things to consider for an ADU Garage Conversion

Sewer line: The city will most likely require you to run a new sewer line from your ADU to the existing sewer lateral in your front yard.  I strongly suggest you have your contractor determine the location and depth of your existing lateral so that they know where they will need to connect your ADU sewer.

Running your new sewer line through a dirt area is much cheaper than running it under a concrete driveway; not to mention that a section of your driveway will need to be ripped up and patched.

Garage Foundation: Your garage is reasonably old and its foundation (the footings under the exterior walls) was built to an earlier standard and building code. These footings may or may not be deep enough to suffice for today’s standards. Your city inspector may require you to dig a hole next to the garage in order to see the depth of the footings. If they aren’t sufficiently deep, you may be required to install deepened footings, requiring the contractor to dig a hole under the existing foundation to add deepened concrete pads. Inquire with your contractor in advance whether they think this will be required and the costs to install these if necessary.

DWP powerlines: If you have DWP power lines at the back of your property, and your garage is currently under the powerlines, the city of LA will not allow you to convert it to an ADU. I suggest inquiring with DWP about relocating the line over your garage; it’s a bit costly & time-consuming, but it is possible.

Renting a garage conversion ADU: You can rent your ADU to a tenant, even if you don’t live on the property (so you can rent both your main house and ADU).  You cannot sell your ADU separately from your main house.

Building an Addition to Your ADU Garage Conversion: If you want to expand your garage before converting it to a living space, there are a few things to keep in mind. Although you can convert your garage to an ADU regardless of its location (even if it’s within the 4-foot setback requirements), any addition you want to build must meet the latest city ADU rules.

Specifically, that means any addition would have to be located at least 4 feet from your side and rear property lines (setback requirements). This applies to a single-story addition to the garage or a second-story built over the garage. In addition, once your garage conversion ADU is over 500 square feet, it will have to meet additional city requirements like LID-“Low Impact Development” (ask your architect more about this).

What are the city guidelines for a Los Angeles garage conversion/ADU? Every city will have different guidelines and requirements for converting your garage so it’s important to inquire with the city building department or hire a local architect who understands all the local guidelines. Depending on where you live, you can find resources for various municipalities in Los Angeles, Ventura, & Orange County in the following blogs:

• What You Need To Know About Ventura County Garage Conversions In 2023

• The New 2023 Orange County Granny Flat and Garage Conversions Guide

• Will 4 New California ADU Laws Help First-Time Home Buyers?

• Can Your Los Angeles Home Become a ‘Duplex’ Under The New ADU Regulations?

Laundry: Since a garage conversion is a living unit, including laundry machines is an important detail. It’s not great to have the garage conversion share laundry with the main house or use a laundromat.

Natural light: Garage conversions are generally pretty small and one way to make them feel larger is to create lots of natural light in the unit. This can be achieved by including the appropriate number of windows, skylights, and glass doors.

Privacy: It’s a smart idea to create privacy between the main home and the garage conversion by building fencing somewhere between the two homes. Also, consider building an access gate that can be used by the garage conversion occupant.

HVAC: Make sure to include a quality HVAC system in your garage conversion, so your occupant is comfortable year-round in the home.

Kitchen island: It may be hard to squeeze in a kitchen island in your garage conversion. But a small island will make a small kitchen more usable and convenient. It’s very practical because it can be used as both a kitchen preparation area and a table.

Storage: Garage conversions are often small and don’t include a garage, so it’s a good idea to include lots of areas for storage. These storage areas can be built-in cabinets, closets, attic areas, or even sheds (search: sheds for sale near me), etc.

Soundproofing: Especially in the case of attached garage conversions, you should ensure there is insulation and maybe even soundproofing material between each home so the occupants aren’t hearing noise coming from each other.

Outdoor area & patio: It’s nice to consider including outdoor private space for your garage conversion, assuming it’s a private space for the occupant. Making a concrete patio or even installing some pavers makes for a good surface for a table or some seating, etc. A few potted plants or landscaping are nice, but a lawn is probably unnecessary. Building a patio cover for shade is a very nice detail, but it may not always be cheap.

Note: If you’ve already got an unpermitted garage conversion, now is a good time to legalize your ADU. Your best first step would be to speak with a garage conversion contractor or architect about the construction that was already done and get their opinion of how much you’ll need to correct to legalize the garage conversion.

The process will be similar to a new garage conversion…start by creating plans, go through plancheck, then have a contractor perform any work necessary to bring it up to code. Finally, the city will inspect your work and issue a certificate of occupancy.

Having a legalized garage conversion will allow you to rent out space and adds value to your property when you go to sell it.

Garage Conversion Frequently Asked Questions (FAQ)

When it comes to finding the best ADU and garage conversion contractor in Los Angeles, Orange County, Ventura or San Diego – GreatBuildz is simplifying the contractor search. GreatBuildz is a free service that connects homeowners with reliable, thoroughly screened general contractors and provides project support from start to finish.

Call now (818.317.3567) to chat with a real person about your next renovation project or visit our website for more information: www.greatbuildz.com

ADU Guidelines for Every City in Los Angeles

• Los Angeles City Garage Conversion Guidelines