A three car garage with an apartment above is one of the most practical and rewarding building projects a homeowner can take on, combining room for vehicles, storage, and a workshop below with valuable living space up top. The garage level is also a finished space in its own right, with walls wide enough for garage wall art from Garage Graphics that gives the room real character. The right 3 car garage with apartment above plans balance parking, living space, and access in a single design. This guide walks through the layouts, dimensions, uses, and planning steps so you can choose a plan that fits your property and your goals.
What Is a 3 Car Garage With Apartment Above?
A three car garage with an apartment above combines a three bay garage on the ground floor with a self contained living unit on the second story. Often called a carriage house or garage apartment, the design uses the same footprint twice, putting parking, storage, and a workshop below and a private living space up top. It is a popular way to add usable square footage to a property without expanding the main house.
What These Plans Typically Include
A complete set of plans covers both levels. On the garage level you will find three parking bays, room for storage or a workshop, a staircase, and space for the mechanical systems that serve the apartment. The upper level holds the living space, which usually includes an open living and kitchen area, one or two bedrooms, a full bathroom, and often a laundry closet. The plans also detail the stair access, the rooflines and dormers that shape the living space, and the routing for plumbing, heating, and electrical service.
Typical Size and Dimensions
A three car garage with an apartment above usually has a footprint of about 32 to 40 feet wide and 22 to 26 feet deep. A common size of 36 by 24 feet gives roughly 860 square feet on each level. Once the staircase and the roofline are accounted for, the apartment above typically offers between 700 and 1,000 square feet of finished living space, which is enough for a comfortable studio, one bedroom, or two bedroom unit.
Ceiling height matters on both floors. The garage level often uses a 9 or 10 foot ceiling to leave room for tall vehicles and to support a comfortable floor above, while the apartment commonly has 8 to 9 foot ceilings, sometimes raised with dormers or a vaulted section for a more open feel.
Popular Layout Options
The right layout depends on how you plan to use the space and how much room the footprint allows.
Studio or One Bedroom Apartment
A studio places the living, sleeping, and kitchen areas in one open room with a separate bathroom, which suits guests, a home office, or short stays. A one bedroom layout adds a private bedroom along with a living room and kitchen, making it a strong choice for a rental or a family suite.
Two Bedroom Apartment
A larger footprint can support a two bedroom apartment with a full kitchen and living area. This layout works well as a long term rental or as living space for family members who want more room and privacy.
Interior vs Exterior Stair Access
Stair placement shapes both the design and the privacy of the apartment. An exterior staircase gives the apartment its own private entrance and frees up interior space, which is ideal for a rental. An interior staircase keeps the climb weather protected and feels more connected to the garage, which suits a guest suite or home office.
Common Uses for the Apartment
The living space above a three car garage is flexible. Many owners use it as a rental unit for steady income, since a private apartment with its own entrance is attractive to tenants. Others use it as an in law suite or guest suite for visiting family, aging parents, or adult children who want independence close to home. The space also serves well as a home office, studio, or quiet retreat away from the main house.
Apartment Layouts Compared
| Apartment Layout | Approximate Living Space | Best For | Key Features |
|---|---|---|---|
| Studio | Smaller | Guests, home office, short stays | Open living and sleeping area, full bath |
| One bedroom | Medium | Rental, in law or guest suite | Separate bedroom, kitchen, living room |
| Two bedroom | Larger | Family rental, long term living | Two bedrooms, full kitchen, larger living area |
Design and Planning Considerations
A few important details separate a plan that works from one that creates problems later.
Utilities and Fire Separation
The apartment needs its own plumbing for the kitchen and bathroom, heating and cooling, and electrical service, so the plans must route these systems from the start. If the unit will be rented, consider separate metering. Building codes also require a fire rated barrier between the garage and the living space above, which protects the apartment from fumes and fire.
Foundation and Structure
A second story adds significant weight, so the foundation and framing must be engineered to carry the load. This is one reason a garage apartment costs more to build than a simple garage, and it is best handled with professional plans and a qualified contractor.
Zoning, Permits, and ADU Rules
Many areas treat a garage apartment as an accessory dwelling unit, which comes with rules on size, parking, height, and whether you can rent it out. These rules vary widely by city and state, and some areas limit short term rentals or require the owner to live on the property. Check your local zoning office early, since these rules can shape the entire design.
Finishing the Garage Level
While the apartment gets most of the attention, the garage level deserves the same care. Durable flooring such as epoxy or sealed concrete handles daily use, and bright lighting makes the space easy to work in. The walls are a chance to add personality, and garage wall graphics or garage wall art turn the bays into a finished space that reflects your passion, from muscle cars to racing scenes. A well finished garage below makes the whole structure feel complete.
Final Thoughts
Three car garage with apartment above plans give you parking, storage, and valuable living space in a single, efficient design. Decide how you want to use the apartment, choose a layout and stair arrangement that match your goals, and plan the utilities, structure, and permits carefully from the start. With the right plan and a finished garage level below, this kind of build adds lasting value and flexibility to any property.
Frequently Asked Questions
How big is a 3 car garage with apartment above? The footprint is usually about 32 to 40 feet wide and 22 to 26 feet deep. The apartment above typically offers between 700 and 1,000 square feet of living space once stairs and the roofline are accounted for.
Can I rent out the apartment above my garage? In many areas, yes, but the rules vary. A garage apartment is often treated as an accessory dwelling unit, and some cities limit rentals or require owner occupancy, so check your local zoning before you build.
How much living space can you fit above a 3 car garage? Most designs provide between 700 and 1,000 square feet upstairs, which is enough for a studio, one bedroom, or two bedroom apartment depending on the footprint and roofline.
Do you need stairs inside or outside for a garage apartment? Both work. An exterior staircase gives the apartment a private entrance and saves interior space, which suits a rental, while an interior staircase keeps the climb weather protected and feels more connected to the garage.
Is a garage with an apartment considered an ADU? In many places, yes. A self contained living unit with a kitchen and bathroom is often classified as an accessory dwelling unit, which carries its own permit and zoning requirements.
What should I consider before building a garage apartment? Plan for the foundation to carry a second story, route utilities for the apartment, include a fire rated barrier between the levels, and confirm local zoning and permit rules before finalizing the design.