Kitchen Remodeling

Building an ADU Above Your Garage: Here’s the (Second) Story

Building an ADU Above Your Garage: Here’s the (Second) Story

March 22, 2023

The prospect of building an above garage ADU is enough to make anyone excited. Creating your very own customized space from design to finishing materials allows you to make something truly unique. With a project this big though, you may be wondering what the build process looks like before you jump in feet first. Who can blame you?

Luckily, there’s more than enough information to put your fears to rest before starting your project. Stick around and find out the different uses for ADUs, benefits and challenges of the build, the process of building, and the estimated costs. Armed with the full knowledge of the process laid out below, you can step confidently into your above garage build!

What is an ADU?

An ADU, or accessory dwelling unit, is a second housing structure that’s built on the same lot as a primary living unit. Generally, they act as a fully functional living space to include a bathroom, kitchen, rooms and the like. ADUs come in many shapes and sizes to fit the lifestyle and needs of all homeowners; There’s something to fit every existing structure!

For example, an ADU can be attached to a ground level structure like most envision when they think of a home addition. They can also be attached above a garage or upper floor. Converting a garage or creating a basement are also ADU options. Finally, you can have a detached ADU that offers an entirely separate structure from the original. All in all, for the purposes of this article we’ll be focusing on the above garage ADU.

Uses of an ADU Above Garage

One of the best parts of building your above garage ADU is that it can accommodate whatever you need. While there’s no set use for your ADU garage, here’s some of the common ones that might spark some inspiration.

  • Home Gym: These spaces can be the perfect set up for the home gym of your dreams. No more long trips to the gym or waiting for equipment!
  • Home Office: A quiet retreat to get all your work done, an ADU is often used as a home office; Take calls and get work done in the solitude you need.
  • Rental: Many homeowners use an above garage ADU as a rental space, producing extra income for their families while keeping their own home private.
  • Mother-in-law Suite: An ideal space for an elderly parent, have peace of mind as they live close in your above garage ADU.
  • Guest Suite: Give your guests the comfort of their own living space while keeping your privacy, but still having them close by.

Benefits of an ADU Above Garage

What’s in it for you? A great question for such a big investment. Luckily, there’s enough benefits to this project that you can rest assured it’s a worthy expenditure.

  • Extra Space : The most obvious benefit of an above garage ADU is the extra space you’ll gain. As mentioned above, this space has unlimited uses, some of which can even make you money! A little extra square footage never hurts, especially when it comes time to sell.
  • Increased ROI : Speaking of selling, you’re sure to see return on investment when it comes time to put your home on the market. Buyers love homes that have unique features or a little something “extra”. An above garage ADU easily fits that bill and will undoubtedly add value to your home.
  • More Eco-friendly : Any kind of construction has undeniable impacts whether through the actual build process itself or materials used. Even so, building up instead of taking up more green space on the ground’s surface makes it a bit more eco-friendly.
  • Added Privacy : A traditional ADU is typically built ground level and attached to the primary home. While the extra space is still valuable, it doesn’t lend itself to privacy when guests are in the home. An above garage ADU can be built in such a way that it has its own entrance, cook space, and the like; All equaling more privacy for you.

Challenges of Building an ADU Above Garage

While building an ADU above the garage will without doubt provide you with plenty of benefits, it’s not without its challenges. You should consider these before jumping into your project; Nothing’s worse than starting a project of this size only to run into major obstacles that cost you more time and money.

  • Cost : As with most things, your budget will determine whether or not you can take on a project like this. Considering the fact that you’re adding an entirely new area to your home from top to bottom; It should come as no shock that the price tag will reflect the magnitude and that might not be feasible for some.
  • Height Restrictions : Building codes aren’t always straightforward. While it may not seem like you’re disturbing much by building up instead of out, that’s not always the case. You’ll need to check local rules and regulations to ensure your above garage ADU is done legally.
  • HVAC Requirements : These days, most people rely on HVAC systems to keep them comfortable with both cooling and heating. Unfortunately, your existing system isn’t likely to support an above garage space. The existing HVAC unit will either need to be modified or an alternative installed like a split unit.
  • Exterior Style : Think about how an above garage ADU will look when it’s all said and done. Adding to an existing structure isn’t an easy task when it comes to style for the simple fact that the same materials aren’t always available. Architectural features will also need to be well thought out to be sure it blends in.
  • Plumbing : Providing proper plumbing to this area of the home can be quite a headache depending on what you’re dealing with. The location of your home’s main sewer pipe connection is what will determine the most. If it’s close to your garage, it could be a fairly simple connection. If it’s not, it could mean trenching out certain parts of the existing haedscape in order to plumb the ADU correctly.

Estimated Costs of Building an ADU Above Garage

With every ADU build comes its own set of detailed plans, materials, and labor needs. That makes the task of estimating ADU building costs a bit more difficult. Even so, there’s a few ways you can get an idea of what your above garage ADU may cost. TO start, here’s estimated costs based on size:

  • 400 square feet: $180,000 to $220,000
  • 600 square feet: $260,000 to $320,000
  • 750 square feet: $340,000 to $420,000
  • Average cost: $250,000

There’s plenty of factors that impact costs aside from square footage, material costs being one of those. Check out the main ones below:

  • Framing
  • Beams and Trusses
  • Roofing
  • Siding
  • Plumbing
  • Mechanical
  • Drywall
  • Insulation
  • Windows
  • Floors
  • Doors
  • Cabinetry
  • Trim
  • Paint

There’s a few other costs to keep in mind despite all of the above. From labor costs to miscellaneous fees, these aren’t aspects of your build you’d want to ignore.

  • Permitting
  • Demolition
  • Architect
  • Structural Engineer (foundation)
  • Plumber
  • Electrician
  • Project Clean-up
  • HVAC Installation

The Process to Build an ADU Above Garage

When you’re investing so much, it’s natural to be curious about what the actual building process looks like. While it’s an intricate project with no lack of moving parts, the steps below give you a birds eye view of the operation.

  1. Acquire Contractor: One of the most important decisions you’ll make in the ADU build process is your choice in contractor. It’s important to pick someone who is known for meeting deadlines and who communicates well. Be sure they’re licensed and insured and someone who specializes in or is at least familiar with the ADU building process. Price is always on consideration as well. To ensure you’re not being taken advantage of, try getting multiple bids on the project for comparison purposes.
  2. Financial Review: You’ll want to review your contractor’s bid. If you’re looking to cut costs, use the bid to see where you might be able to trim. Adjusting the overall design of your ADU may also cut the cost of your project’s total cost. In this phase, you’ll also need to decide which financing option best fits your needs. Between grants, loans, and lines of credit you have options.
  3. Feasibility Study: This study is a crucial part of the build process as it ensures your build is doable given the utilities from the main house, available lot space, local requirements, and the like. Ensuring that your space is viable for the project and meets building code will save you a huge headache in the end, avoiding possible pitfalls that are identified in the study itself.
  4. City Consult & Permitting: If all is well with the feasibility study, your contractor can now submit a complete set of drawings to the city. Alongside these drawings, they’ll begin working on the permitting needed for everything. Pulling these permits allows the work to be done legally and safely for all involved.
  5. Finalize Aesthetics: Probably the most fun step in the process is finalizing the materials used in your ADU build. Most people already have an idea of how they’d like their ADU to look both inside and out. If not, their contractor can supply them with 3D mock ups and material options from siding to flooring.
  6. Construction Begins: Finally, with all the nitty gritty details pegged down, your build out can officially begin! Completion times vary depending upon how big or small your project is and what customizations are being added. You can usually expect a build from beginning to end to take anywhere from 7 to 16 months.

Ideas and Tips for an ADU Above Garage

There’s no shortage of ideas and tips for your above garage ADU build. From prepping for your project to the details of your design, consider the ideas below as you move forward.

  • Clean out the attic: It sounds like a no-brainer, but you’d be surprised the amount of people who forget they’ve stored items in their attic; Then in comes their demolition crew only to find their workday delayed by having to get the homeowners to move their items out of the workspace. Check your attic before!
  • Choose timelines wisely: While an ADU garage build doesn’t cause as much disruption as a full second story addition, it’s still going to affect your day to day life. Consider the fact that your contractor will need your driveway and likely surrounding space for materials and equipment. Select a time of year that works best for your family, keeping in mind the short inconveniences of less parking, more noise, and the like.
  • Don’t neglect the light: An above garage ADU will undoubtedly provide you with added square footage but the space is still likely to be small. That’s where the power of natural light comes in as it can make the space feel bigger. Try to keep this in mind when designing your ADU garage to maximize light in your space.
  • Consider skylights: Speaking of natural light, skylights are both an excellent and unique way to introduce it into your space. They’re also a great way to ventilate your new ADU garage. Many skylights have the ability to open, so you have the added benefit of fresh air flowing through your unit.
  • Pick a functional design: What are you using the space for? It’s critical that you plan your ADU with this question in mind. Remembering your overall goal for your ADU will help you make design choices that make the most sense for how you plan to use the space. Do you need storage or shelving? Maybe a wide open space or a few separate rooms? Even a small cook space or built in seating.
  • Stair location: Depending on the size of your existing garage and the surrounding elements of your exterior, you may have the ability to choose whether you’d like the stairs to your ADU inside or outside. You can have a set inside the ground level of your garage that leads to the ADU’s door or a set of stairs on the exterior of the home that lead up to an exterior door.
  • Matching windows: A common mistake in above garage ADUs is mismatched windows. It’s a dead giveaway on the exterior that the space above the garage is in fact an addition and not original. To make the home’s exterior look cohesive, choose the same window size for your ADU garage as you have for the rest of your home.
  • Consider roof features: Another common error in above garage ADUs is building the roofline without features. Again, you can usually spot a second story addition easily when the roofline has been neglected. Choosing unique featured gables or dormers help solve this problem while creating an exterior that doesn’t look boring and boxy.

Why choose Structura Remodeling for your ADU garage in Los Angeles?

You may be asking yourself why you should choose Structura Remodeling for your project. There’s no shortage of contractors to choose from, so what sets Structura apart? Here’s more than enough reasons to make Structura your number one choice:

  • They have over 16 years of experience in the construction industry with the owner being a third generation contractor.
  • Their team is made up of the most qualified individuals in the field, between designers and craftsmen, you’re working with the best in the business.
  • They operate each project via a comprehensive process, starting with your vision, to full estimates, home design and the like.
  • The company is extremely detail oriented, making your dreams come to life down to every cabinet pull and color. With the help of 3D renderings and project planning, you can be sure your vision will come to fruition.
  • The level of professionalism on site is unparalleled. The team works to keep their work space clean while taking care of surrounding job site elements like pets, family schedules, and your possessions.
  • Structura Remodeling truly cares about the customer’s experience and end result so much so that they always aim for 100% satisfaction with each customer.
  • If all of these combined haven’t convinced you, let the reviews speak for themselves! Countless happy customers have rave reviews for Structura Remodeling!


An above garage ADU may be costly, but the price is definitely worth the reward. A versatile space you can use for nearly any purpose, it fits the needs of every family. Not every contractor can take on an intricate project like this though. You want an experienced company that can guide you through every step of the way.

Ready to get started on your above garage ADU? We’re ready to assist! Get a FREE ADU consultation in the Los Angeles area! Call Structura Remodeling at 1-800-922-4613 or schedule a free consultation here:


*Serving Los Angeles county and surrounding areas*


Is it cheaper to build out or up?

While above garage ADUs make an awesome addition to any home, building out is by far the cheapest option. Sure, when you build out you have to fork over money for excavation, surveying, added foundation and the like. Even so, starting from scratch helps to mitigate some major obstacles that adding a story to an existing garage just doesn’t present.

The fact is, building up requires a lot more detailed work to ensure the structure is on solid foundation and built to fit seamlessly into the existing home’s style. Extra materials and labor also add to the cost of building up. While it has its benefits, they come at a cost.

Are ADUs worth the investment?

An ADU is no small project and with it comes a price tag that may scare off some. For those who can see the long term value though, ADUs are well worth the investment. Surveys on the return on investment for these structures report an average of a 35% bump in sale value.

ROI aside, they’re worth the investment when it comes to extra space alone. They’re perfect for expanding families and a place for your out of town guests. Not to mention the possibility of using ADUs for an AirBnB site. They have endless potential!

What is a JADU?

Similar to an ADU, a JADU or junior accessory dwelling unit, is also a housing structure built with the intent for living with one caveat: it’s no bigger than 500 square feet. As a rule of thumb, JADUs are attached to the home and because of the smaller space they don’t have the full amenities of an ADU.

For instance, you’ll find JADUs likely share a bathroom with the main living quarters, not always a separate bathroom as with ADUs. Similarly, JADUs will have some type of space for prepping food but not a full kitchen for cooking.

What is a UDU?

A UDU, or unpermitted dwelling unit, is an ADU that has not been built under proper permitting. This is often the result of a DIY with the best intentions. While it can be tempting to construct an ADU on your own, the risk is not worth the reward in this case. Using a trusted contractor like Structura Remodeling ensures everything’s done legally.

If not, you run the risk of having to revert back to legalizing your ADU which is not only a hassle, but not always doable. You’ll need to study county codes, bring the unit to standard, submit plans, undergo inspections and so forth. If you’re lucky, you can make things right, but it’s not a chance you’ll want to take.