• March


  • 127741
  • 0
Featured Video Play Icon

How to Add a Bonus Room Above a Garage

Over-the-garage additions have become very popular addition style for homeowners in recent years. This is largely due to the fact that they are an easy way to add space within the home’s existing structure. Whether you want to add on a bedroom, a playroom for the kids, or even a “man cave,” there are tons of options for how to use your garage bonus room. Here’s a step by step guide on how to add a bonus room above your garage.
Benefits of Adding a Bonus Room Above Garage
There are multiple benefits to adding a room above your garage. Here are some of the top decision-influencers.
No Additional Footprint
Debatably the biggest perk of opting for an above-garage addition is that it doesn’t increase a house’s footprint. You can easily add on to the existing structure of your home by building up, rather than out. So the size of your lawn and property square footage remains exactly the same.  
Saved Cost
Another nice thing about building a bonus room over your garage is that when make the necessary structure additions, such as adding new support posts, beams and concrete footings, you don’t have to worry about destroying a finished room below. Since you’re building over the garage, the cost of remodeling the existing space as you add new structural elements is minimal.
Positive Impact on Curb Appeal
Over-the-garage additions have a huge impact on curb appeal of your home since they usually face the street and tend to be large. Considering the size of a typical two-car garage (24 feet by 24 feet, or bigger), installing a finely finished garage bonus room can drastically increase not only the visual appeal, but also the resale value of your home.
Difficulties of Adding a Bonus Room Above Garage
As with any home addition, there are inevitably some complexities and challenges to adding a bonus room above your garage. Here are three to be aware of.
Seamless Design
Since above-garage additions are so sizeable, it’s all the more important that the bonus room seamlessly blends with the exterior facade of your home.
This is especially difficult since many times the exterior finish of the garage and main house may be more than 20+ years old, and your bonus room addition will, of course, be brand new. Finding siding, shingles, brick, stone or other material to match the existing home can be a real challenge.
A few strategies, according to This Old House, that can help your bonus room addition appear seamless are: “making sure features such as gables and windows are harmonious with the house’s style, adding facade details, like trim, to break up expanses of siding, and, if possible, scheduling the project in tandem with an exterior upgrade, like repainting or re-siding.”
Possible Restrictions
Another potential issue with building above your garage is the possibility of running into restrictions. Before you move forward with any sort of planning, check with the city or local jurisdiction to see if they have any height restrictions for a detached garage. Some local jurisdictions may require additional parking build on site, or if the garage is closer than five feet to the property line, many codes will not allow you to build windows or doors.
Building a Stiff Floor
Due to the size of standard garages, the long, open spans of space can make it difficult to build a stiff floor that supports the people and rooms above without interfering with the car space below. The floor needs to be sturdy enough so it complies with any codes, does not bounce, and also doesn’t interfere with any functionality in the garage (such as the garage door opening).
Cost of Adding a Bonus Room Above the Garage
With any home renovation, cost and budget are some of the first questions that every homeowner has.
There are many factors to take into account when estimating approximate costs. Probably the biggest factor when determining the cost of your renovation is going to the size of your bonus room. Construction costs are estimated by square foot, so the larger the room is, the more it will cost.
Another significant factor is the scope of work that needs to be done in that space. Since you’re building a brand new room on top of the garage, the space may require extra insulation or wiring that an addition in a different part of the home might not.  
Aside from the cost of the space are the costs of the materials used to complete the renovation and the people who do the work. The great news about materials is that, in today’s day and age, it’s easier than ever to find cost-efficient materials, many of which emulate a higher dollar option. For example, engineered plank vinyl is significantly less expensive than true hardwood, but achieves almost the exact same look.
When it comes to personnel, this is definitely an area where to do not want to skimp. Depending on the level of work that needs to be done, you can certainly handle some elements on your own – such as laying down manufactured flooring or installing drywall. But for significant structural and design changes, you will definitely want to work with a contractor and/or architect to ensure your addition turns out exactly the way you envision.
Average Cost of Adding a Bonus Room Above a Garage
For all the reasons mentioned above, the cost of finishing a bonus room above your garage can vary.  According to Salter Spiral Stair, “the approximate cost of finishing the bonus room over your garage is approximately $35 per square foot. This is calculated from standard costs for all of the different finishing pieces, such as the insulation, flooring, and wiring.”
Step-by-Step Guide – How to Add Bonus Room Above a Garage
Here is a loose step-by-step breakdown of how to add a bonus room above a garage in your home.
1. Think from the Outside-In
When you are starting to envision your dream addition, sometimes it helps to think from the outside-in. Meaning, since over-garage additions are so visible, and usually of a significant size, start with what you want it to look like from the outside, and work backwards on how that might affect structure. As mentioned earlier, the design of your bonus room will need to be seamless with the facade of the rest of your home’s exterior.
If you’re looking for some inspiration for where to start with your bonus room above the garage, there’s no shortage of styles or aesthetics. You could go for a more contemporary design, or opt for traditional, like this addition design over a three-car garage in this Minneapolis home.
2. Verify the Structure
Once you have an idea of what you might want, you can start to think about your home’s structure and how to build on it. This means an engineer will need to verify that the garage’s existing framing and foundation can bear the weight of an addition.
For the foundation, a contractor will need to dig several holes to check its depth and condition along the garage’s perimeter. If the foundation isn’t supportive enough, it will need to be bolstered or replaced, which can be expensive.
3. Check Against Safety Codes
Safety concerns and regulations should be addressed early on in your bonus room-planning process. For example, building code requires 5/8-inch-thick fire-rated drywall, known as Type X, on the garage ceiling and walls when an addition is put on above. This drywall helps to protect the framing against the possibility of fire. In addition, penetrations in the drywall, for electrical conduit and the like, must be sealed tightly.
The walls are always one of the most important parts of finishing any room, and same definitely goes for a bonus room above the garage. The walls create the frame that you can then build on top of for the rest of your bonus room’s design.
The first thing you will want to do is ensure that your space in properly insulated.
In addition to standard, safety-mandated insulation, you may want to consider installing additional insulation in your above-garage addition to help keep the area more comfortable. Otherwise, your addition make take on a drafty quality, or you will waste money on heating and cooling the space.  
After you’ve installed insulation in the walls of your bonus room, you’ll want to hang drywall as the base of any other wall treatments you may want to apply over it. This “gives your bonus room a finished look and brings it into the same design style as your main home’s interior” (Salter Spiral Stair).
To finish your walls, paint is the most common, most affordable choice, but if you want to make your space truly unique, a custom finish, like wallpaper, decals, or even a material like shiplap can make all the difference.
When it comes to the floors of your bonus room above the garage, there are a few factors you’ll need to consider. First, most above-garage additions have basic frames that were not originally built for heavy foot traffic and regular use. So, the first thing you’ll want to do is reinforce your floor joists.
Once the floor joists are reinforced, you will need to add insulation. This will help with noise control as well as temperature control. You can also choose to add another layer of noise insulation to your garage loft by opting for carpet as your floor material. If you choose carpet, you will need to install subflooring underneath it, which will also help with support.
Hardwood flooring won’t be as sound efficient, but it can be a more cost-efficient option, with lots of materials to choose from.
4. Think About Plumbing & Utilities
Especially if you want to add a bathroom in your above-garage addition, you will need to spend some time considering plumbing and utilities.
Extending plumbing pipes and drains to a new bathroom or even a laundry room above a garage can be very challenging. Especially if your home’s existing wastewater drain is located a substantial distance from your addition, you can expect significant renovation costs.
Another noteworthy fact for planning a bathroom in your bonus room is that any pipes will need to stay in areas that are heated and not in exterior walls, where they would be susceptible to extreme cold or heat. Your contractor can certainly help you plan for this.
Your contractor can also help you with planning electrical needs. Your garage might be on your current power grid, but you will still need additional wiring to allow for more lighting and electronics that you may put in your bonus room.
5. Work With Available Space & Access
This reminder may seem obvious, but working with your existing space and framework will save you lots of headaches. Rule out impossible plans early on – if you have a single car garage, squeezing in two bedrooms and a bathroom in your “bonus room” is probably off the table.
Most two-car garages are about 400 square feet, so you should have enough room for a nice size sleeping room and a bathroom and closet, or a sizeable living space.
Creating Access Points
Once you’ve gone through all the time, cost and effort to create a beautiful bonus room above your garage, you’re going to want a safe and equally beautiful way to access your space. Namely, through a staircase.
Interior Access
If you plan to install your bonus room stairs inside your garage, you’ll want to ensure that you don’t take up a lot of space. You want to leave as much space available as possible.
Probably the most space-efficient option is a ladder, which is a very common loft stair design. Ladders are also nice since they can be moved around as needed. However, if you are turning your above-garage room into an in-law suite, or some other room that will be frequently accessed, a ladder probably isn’t your best option.

Another common option is the traditional straight staircases. This option is very stable and easy to use, but it definitely takes up the most space.

The more trendy option in recent years and a happy medium between a ladder and a straight staircase is the spiral staircase. This design takes up a small circle in the corner of your garage, leaving the maximum amount of space on both floors.
Exterior Access
To maximize the interior space in your bonus room and garage, you can also choose an outdoor access staircase. When it comes to exterior access, you can opt for a traditional outdoor staircase which is traditionally sealed wood, or a variation of a spiral staircase. Both options will carry a more casual look and feel, so you should definitely take that into account with the desired aesthetic of your bonus room addition.  



Subscribe to Newsletter
  • This field is for validation purposes and should be left unchanged.

Latest Posts

© Copyright 2016 - Remodel Works - Contractor License #781576